I am a gastroenterologist who seeks to use both science and clinical practice to improve the prevention, diagnosis, and therapy of digestive malignancies. My clinical practice is focused on the use of advanced endoscopic imaging procedures (such as endoscopic ultrasound, chromoendoscopy, and confocal endomicroscopy) to improve cancer detection, and therapeutic endoscopic procedures to remove or destroy cancer and precancerous lesions.

My research is aimed at improving digestive cancer outcomes and reducing cancer disparities through data science, cohort building, and biomarker development. My research is currently supported by an NIH Mentored Career Development Award (K08CA252635). I have formal pre-doctoral (NIH-Clinical Research Training Program) and post-doctoral (T32DK007056) training in epidemiology and clinical research.

Clinical Focus

  • Gastroenterology
  • ERCP, endoscopic ultrasound, luminal stenting, small bowel endoscopy
  • gastric cancer, gastric intestinal metaplasia and premalignant lesions

Academic Appointments

Honors & Awards

  • Fellow, American Society of Gastrointestinal Endoscopy (ASGE) (2024)
  • Diversity Investigator Award, Stanford Department of Medicine (2021)
  • Health Disparities Research Institute Scholar, NIMHD (2021)
  • K08 Mentored Career Development Award (CA252635), National Cancer Institute (2021)
  • Resource Center for Minority Aging Career Development Grant, National Institutes of Aging (P30AG0059304) / Rutgers University (2021)
  • Young Physician Leadership Scholar, American College of Gastroenterology (2020)
  • North American International Training Grant, American College of Gastroenterology (2019)
  • Top Reviewer, Annals of Internal Medicine (2018)
  • Chief Fellow, Division of Gastroenterology, Stanford University (2016-2017)
  • T32 Institutional Research Training Grant (DK007056), National Institutes of Health (2015-2017)
  • William G. Anlyan Scholarship, Duke University School of Medicine (2010)
  • NIH-Clinical Research Training Program (CRTP), National Institutes of Health (2009-2010)
  • Harvard College Scholar, Harvard College (2003-2005)

Professional Education

  • Fellowship: Stanford University Gastroenterology Fellowship (2017) CA
  • Residency: Stanford University Internal Medicine Residency (2014) CA
  • Board Certification: American Board of Internal Medicine, Gastroenterology (2018)
  • Board Certification: American Board of Internal Medicine, Internal Medicine (2014)
  • Residency, Stanford Hospital and Clinics, Internal Medicine (2014)
  • Medical Education: Duke University School of Medicine (2011) NC
  • M.D., Duke University School of Medicine (2011)
  • A.B., Harvard College, Biochemical Sciences, magna cum laude (2007)

Current Research and Scholarly Interests

Epidemiology of gastric cancer
Racial and ethnic disparities in gastric cancer
Gastric intestinal metaplasia and other precancerous lesions
Molecular marker development

Clinical Trials

  • The Gastric Cancer Foundation: A Gastric Cancer Registry Recruiting

    The Gastric Cancer Registry will combine data acquired directly from patients with gastric cancer; with a family history of gastric cancer in a first or second degree relative; or persons with a known germline mutation in their CDH1 (E-Cadherin) gene via an online questionnaire with genomic data obtained from saliva, blood and tissue samples. The purpose of this registry is to gain better understanding of the causes of gastric cancer, both environmental and genetic; whether certain genomic data can predict outcomes of treatment and survival.

    View full details

  • The GAstric Precancerous Conditions Study Recruiting

    Gastric cancer afflicts 27,000 Americans annually and carries a dismal prognosis. One reason for poor outcomes is late diagnosis, as the majority of gastric cancers in the United States are diagnosed at a relatively advanced stage where curative resection is unlikely. Gastric intestinal metaplasia (GIM) is a precancerous change of the stomach which increases risk for subsequent gastric cancer multiple-fold. The Gastric Precancerous Conditions Study (GAPS) is an observational study with two over-arching objectives: 1) improve the non-invasive identification of patients with GIM, and 2) develop biological markers to predict the subset of GIM which will progress onto gastric cancer. To achieve Aim 1, a case-control study (N=300 pairs) matching cases of GIM with age-/gender-matched controls will be recruited form the population of subjects undergoing clinically-indicated endoscopy. Determination of gastric pathology will be made by two, independent gastrointestinal pathologists. At time of endoscopy, a detailed clinical questionnaire is administered by face-to-face interview. Saliva and blood is collected prior to endoscopy. At time of endoscopy, protocoled clinical biopsies (per Revised Sydney Protocol) as well as additional research specimens are collected. Scoring of GIM will be performed based on the Operative Link for GIM scoring system. To achieve Aim 2, patients with histologically-confirmed GIM (N=300) will be followed longitudinally. Biennial endoscopic surveillance will be performed, with repeat biopsies, specimen collection, and histologic scoring. Progression of GIM will be defined as upstaging of GIM score, or development of either dysplasia or carcinoma on any biopsy.

    View full details


  • The Stanford Gastric Precancerous Conditions Study (GAPS)

    The goal of the Stanford GPC Study is to 1) identify non-invasive markers to identify patients at high risk for advanced GPCs and 2) develop molecular risk stratification models to predict which patients with advanced GPCs will progress onto gastric cancer. We are seeking to recruit subjects between the ages of 30 to 84 with 1) a personal history of GPC (either intestinal metaplasia or gastric atrophy) 2) a family history of gastric cancer or 3) dyspepsia or abdominal pain. The research involves a brief questionnaire, blood draw, saliva specimen, and gastric biopsies. We hope that through this research we will develop molecular tests which will improve the early detection of gastric cancer.


    Stanford, CA

All Publications

  • Risk of Gastric Adenocarcinoma in a Multiethnic Population undergoing Routine Care: an Electronic Health Records Cohort Study. Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology Huang, R. J., Huang, E. S., Mudiganti, S., Chen, T., Martinez, M. C., Ramrakhiani, S., Han, S. S., Hwang, J. H., Palaniappan, L. P., Liang, S. Y. 2024


    Gastric adenocarcinoma (GAC) is often diagnosed at advanced stages and portends a poor prognosis. We hypothesized that electronic health records (EHR) could be leveraged to identify individuals at highest risk for GAC from the population seeking routine care.This was a retrospective cohort study, with endpoint of GAC incidence as ascertained through linkage to an institutional tumor registry. We utilized 2010-2020 data from the Palo Alto Medical Foundation, a large multispecialty practice serving Northern California. The analytic cohort comprised individuals aged 40-75 receiving regular ambulatory care. Variables collected included demographic, medical, pharmaceutical, social, and familial data. Electronic phenotyping was based on rules-based methods.The cohort comprised 316,044 individuals and ~2 million person-years (p-y) of observation. 157 incident GACs occurred (incidence 7.9 per 100,000 p-y), of which 102 were non-cardia GACs (incidence 5.1 per 100,000 p-y). In multivariable analysis, male sex (HR 2.2, 95% CI 1.6-3.1), older age, Asian race (HR 2.5, 95% CI 1.7-3.7), Hispanic ethnicity (HR 1.9, 95% CI 1.1-3.3), atrophic gastritis (HR 4.6, 95% CI 2.2-9.3), and anemia (HR 1.9, 95% CI 1.3-2.6) were associated with GAC risk; use of non-steroidal anti-inflammatory drug was inversely associated (HR 0.3, 95% CI 0.2-0.5). Older age, Asian race, Hispanic ethnicity, atrophic gastritis, and anemia were associated with non-cardia GAC.Routine EHR data can stratify the general population for GAC risk.Such methods may help triage populations for targeted screening efforts, such as upper endoscopy.

    View details for DOI 10.1158/1055-9965.EPI-23-1200

    View details for PubMedID 38231023

  • COVID-19 pandemic impact on opioid overdose deaths among racial groups within the United States: an observational cross-sectional study. British journal of anaesthesia Chu, R., Sarnala, S., Doan, T., Cheng, T., Chen, A. W., Jamal, A., Kim, G., Huang, R., Srinivasan, M., Palaniappan, L., Gross, E. R. 2023

    View details for DOI 10.1016/j.bja.2023.10.024

    View details for PubMedID 37977954

  • The association between local area immigrant fraction and prevalence of cardiovascular diseases in the United States: an observational study. Lancet regional health. Americas Shokeen, D., Wang, N., Nguyen, N. P., Bakal, E., Tripathi, O., Palaniappan, L. P., Huang, R. J. 2023; 27: 100613


    Local area immigrant fraction is strongly and positively correlated with local life expectancy in the United States. The aim of the study was to determine the relationship between local area immigrant fraction and local prevalence of coronary heart disease (CHD) and stroke.Cross-sectional study design, with ZIP code as the unit of observation. Demographic data was obtained from the American Community Survey, and linked to indicators of health access (e.g., insurance, annual check-ups, cholesterol screening), obesity, behavior (smoking, exercise), and cardiovascular outcomes data from the 2020 Population Level Analysis and Community Estimates. Multivariable regression and path analyses were used to assess both direct and indirect relationships among variables.CHD prevalence was lower in the second (3.9% relative difference, 95% CI: 3.1-4.5%), third (6.5%, 95% CI: 5.8-7.1%), and fourth (14.8%, 95% CI: 14.1-15.8%) quartiles of immigrant fraction compared to the lowest (p-trend <0.001). These effects remained robust in multivariable analysis following adjustment for indicators of access, obesity, and behavioral variables (p-trend <0.0001). For stroke, only the highest quartile demonstrated a significant difference in prevalence (2.1%, 95% CI: 1.2-3.0% with full adjustment). In CHD path analysis, ∼45% of the association of immigrant fraction was direct, and ∼55% was mediated through lower prevalence of deleterious behaviors (e.g., smoking). In stroke path analysis, the effect was entirely mediated through indirect effects.In the United States, ZIP codes with higher immigrant fractions have lower prevalence of cardiovascular diseases. These associations are partially mediated through differences in health behaviors at the community level.NIH (K08CA252635, P30AG0059304, K24HL150476), Stanford University, Rutgers University.

    View details for DOI 10.1016/j.lana.2023.100613

    View details for PubMedID 37860751

    View details for PubMedCentralID PMC10582736

  • Detection and surveillance of gastric cancer precursors: evolving guidelines and technologies ANNALS OF LAPAROSCOPIC AND ENDOSCOPIC SURGERY Koh, J., Shunt, M., Hwang, J., Huang, R. J. 2023; 8
  • A spatially mapped gene expression signature for intestinal stem-like cells identifies high-risk precursors of gastric cancer. bioRxiv : the preprint server for biology Huang, R. J., Wichmann, I. A., Su, A., Sathe, A., Shum, M. V., Grimes, S. M., Meka, R., Almeda, A., Bai, X., Shen, J., Nguyen, Q., Amieva, M. R., Hwang, J. H., Ji, H. P. 2023


    Gastric intestinal metaplasia (GIM) is a precancerous lesion that increases gastric cancer (GC) risk. The Operative Link on GIM (OLGIM) is a combined clinical-histopathologic system to risk-stratify patients with GIM. The identification of molecular biomarkers that are indicators for advanced OLGIM lesions may improve cancer prevention efforts.This study was based on clinical and genomic data from four cohorts: 1) GAPS, a GIM cohort with detailed OLGIM severity scoring (N=303 samples); 2) the Cancer Genome Atlas (N=198); 3) a collation of in-house and publicly available scRNA-seq data (N=40), and 4) a spatial validation cohort (N=5) consisting of annotated histology slides of patients with either GC or advanced GIM. We used a multi-omics pipeline to identify, validate and sequentially parse a highly-refined signature of 26 genes which characterize high-risk GIM.Using standard RNA-seq, we analyzed two separate, non-overlapping discovery (N=88) and validation (N=215) sets of GIM. In the discovery phase, we identified 105 upregulated genes specific for high-risk GIM (defined as OLGIM III-IV), of which 100 genes were independently confirmed in the validation set. Spatial transcriptomic profiling revealed 36 of these 100 genes to be expressed in metaplastic foci in GIM. Comparison with bulk GC sequencing data revealed 26 of these genes to be expressed in intestinal-type GC. Single-cell profiling resolved the 26-gene signature to both mature intestinal lineages (goblet cells, enterocytes) and immature intestinal lineages (stem-like cells). A subset of these genes was further validated using single-molecule multiplex fluorescence in situ hybridization. We found certain genes (TFF3 and ANPEP) to mark differentiated intestinal lineages, whereas others (OLFM4 and CPS1) localized to immature cells in the isthmic/crypt region of metaplastic glands, consistent with the findings from scRNAseq analysis.using an integrated multi-omics approach, we identified a novel 26-gene expression signature for high-OLGIM precursors at increased risk for GC. We found this signature localizes to aberrant intestinal stem-like cells within the metaplastic microenvironment. These findings hold important translational significance for future prevention and early detection efforts.

    View details for DOI 10.1101/2023.09.20.558462

    View details for PubMedID 37786704

    View details for PubMedCentralID PMC10541579

  • Software Application Profile: dynamicLM-a tool for performing dynamic risk prediction using a landmark supermodel for survival data under competing risks. International journal of epidemiology Fries, A. H., Choi, E., Wu, J. T., Lee, J. H., Ding, V. Y., Huang, R. J., Liang, S., Wakelee, H. A., Wilkens, L. R., Cheng, I., Han, S. S. 2023


    MOTIVATION: Providing a dynamic assessment of prognosis is essential for improved personalized medicine. The landmark model for survival data provides a potentially powerful solution to the dynamic prediction of disease progression. However, a general framework and a flexible implementation of the model that incorporates various outcomes, such as competing events, have been lacking. We present an R package, dynamicLM, a user-friendly tool for the landmark model for the dynamic prediction of survival data under competing risks, which includes various functions for data preparation, model development, prediction and evaluation of predictive performance.IMPLEMENTATION: dynamicLM as an R package.GENERAL FEATURES: The package includes options for incorporating time-varying covariates, capturing time-dependent effects of predictors and fitting a cause-specific landmark model for time-to-event data with or without competing risks. Tools for evaluating the prediction performance include time-dependent area under the ROC curve, Brier Score and calibration.AVAILABILITY: Available on GitHub [].

    View details for DOI 10.1093/ije/dyad122

    View details for PubMedID 37670428

  • Why Are We Going Backward? Barriers to Disaggregated Racial Information in Federal Data Sets. American journal of public health Jamal, A., Srinivasan, M., Kim, G., Huang, R. J., Palaniappan, L. 2023: e1-e4

    View details for DOI 10.2105/AJPH.2023.307339

    View details for PubMedID 37319392

  • ASGE Upper GI Tract: A Potpourri of AI, Imaging, Resection and Myotomy AN ANALYSIS OF RISK FACTORS FOR GASTRIC INTESTINAL METAPLASIAdTHE STANFORD GAPS STUDY Shum, M., Huang, R., Kim, J., Hwang, J. MOSBY-ELSEVIER. 2023: AB1234-AB1235
  • Controlling Gastric Cancer in a World of Heterogeneous Risk. Gastroenterology Huang, R. J., Laszkowska, M., In, H., Hwang, J. H., Epplein, M. 2023


    Gastric cancer (GC) is a leading cause of global mortality, but also a cancer whose footprint is highly unequal. This review aims to define global disease epidemiology, critically appraise strategies of prevention and disease attenuation, and assess how these strategies could be applied to improve outcomes from GC in a world of variable risk and disease burden. Strategies of primary prevention focus on improving the detection and eradication of the main environmental risk factor, Helicobacter pylori. In certain countries of high incidence, endoscopic or radiographic screening of the asymptomatic general population has been adopted as a means of secondary prevention. By contrast, identification and targeted surveillance of individuals with precancerous lesions (such as intestinal metaplasia) is being increasingly embraced in nations of low incidence. This review will also highlight existing knowledge gaps in GC prevention, as well as the role of emerging technologies for early detection and risk stratification.

    View details for DOI 10.1053/j.gastro.2023.01.018

    View details for PubMedID 36706842

  • Low rates of structured advance care planning documentation in electronic health records: results of a single-center observational study. BMC palliative care Wu, A., Huang, R. J., Colon, G. R., Zembrzuski, C., Patel, C. B. 2022; 21 (1): 203


    BACKGROUND: Proper advance care planning (ACP) documentation both improves patient care and is increasingly seen as a marker of high quality by governmental payers. The transition of most medical documentation to electronic health records (EHR) allows for ACP documents to be rapidly disseminated across diverse ambulatory practice settings. At the same time, the complexity and heterogeneity of the EHR, as well as the multiple potential storage locations for documentation, may lead to confusion and inaccessibility. There has been movement to promote structured ACP (S-ACP) documentation within the EHR.METHODS: We performed a retrospective cohort study at a single, large university medical center in California to analyze rates of S-ACP documentation. S-ACP was defined as ACP documentation contained in standardized locations, auditable, and not in free-text format. The analytic cohort composed of all patients 65 and older with at least one ambulatory encounter at Stanford Health Care between 2012 and 2020, and without concurrent hospice care. We then analyzed clinic-level, provider-level, insurance, and temporal factors associated with S-ACP documentation rate.RESULTS: Of 187,316unique outpatient encounters between 2012 and 2020, only 7,902 (4.2%) contained S-ACP documentation in the EHR. The most common methods of S-ACP documentation were through problem list diagnoses (3,802; 40.3%) and scanned documents (3,791; 40.0%). At the clinic level, marked variability in S-ACP documentation was observed, with Senior Care (46.6%) and Palliative Care (25.0%) demonstrating highest rates. There was a temporal trend toward increased S-ACP documentation rate (p<0.001).CONCLUSION: This retrospective, single-center study reveals a low rate of S-ACP documentation irrespective of clinic and specialty. While S-ACP documentation rate should not be construed as a proxy for ACP documentation rate, it nonetheless serves as an important quality metric which may be reported to payers. This study highlights the need to both centralize and standardize reporting of ACP documentation in complex EHR systems.

    View details for DOI 10.1186/s12904-022-01099-9

    View details for PubMedID 36419072

  • Catching Up with the World: Pepsinogen Screening for Gastric Cancer in the United States. Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology Zhou, M. J., Huang, R. J. 2022; 31 (7): 1257-1258


    Gastric cancer remains a deadly cancer with poor outcomes in the United States. There is a need for screening strategies for gastric cancer in the U.S. population. With progressive Helicobacter pylori-mediated inflammation of the gastric mucosa, pepsinogen I levels decrease and the pepsinogen I/II ratio decreases. Pepsinogen test positivity (PG+) has been evaluated as a promising screening test among Asian and European populations; however, its utility in multiethnic U.S. populations is poorly described. In this case-control study nested within the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial, In and colleagues evaluate the discrimination of PG+ in serum collected from individuals prior to the development of gastric cancer. The authors find that PG+ individuals were at nearly 10-fold increased risk for developing gastric cancer, and this effect remained robust after adjusting for Helicobacter pylori status, family history, education, smoking, and obesity. In subgroup analysis, the predictive ability of the test was particularly robust for noncardia gastric cancers, and nonpredictive of cardia gastric cancers. Serum pepsinogen testing holds promise as a noninvasive screening strategy to triage individuals at heightened risk for gastric cancer, and may help to improve early diagnosis in the United States. See related article by In et al., p. 1426.

    View details for DOI 10.1158/1055-9965.EPI-22-0372

    View details for PubMedID 35775231

  • The Gastric Cancer Registry: A Genomic Translational Resource for Multidisciplinary Research in Gastric Cancer. Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology Almeda, A. F., Grimes, S. M., Lee, H., Greer, S., Shin, G., McNamara, M., Hooker, A. C., Arce, M. M., Kubit, M., Schauer, M. C., Van Hummelen, P., Ma, C., Mills, M. A., Huang, R. J., Hwang, J. H., Amieva, M. R., Han, S. S., Ford, J. M., Ji, H. P. 2022


    Gastric cancer (GC) is a leading cause of cancer morbidity and mortality. Developing information systems which integrate clinical and genomic data may accelerate discoveries to improve cancer prevention, detection, and treatment. To support translational research in GC, we developed the GC Registry (GCR), a North American repository of clinical and cancer genomics data.Participants self-enrolled online. Entry criteria into the GCR included the following: (1) diagnosis of GC, (2) history of GC in a first- or second-degree relative, or (3) known germline mutation in the gene CDH1. Participants provided demographic and clinical information through a detailed survey. Some participants provided specimens of saliva and tumor samples. Tumor samples underwent exome sequencing, whole genome sequencing and transcriptome sequencing.From 2011-2021, 567 individuals registered and returned the clinical questionnaire. For this cohort 65% had a personal history of GC, 36% reported a family history of GC and 14% had a germline CDH1 mutation. 89 GC patients provided tumor samples. For the initial study, 41 tumors were sequenced using next generation sequencing. The data was analyzed for cancer mutations, copy number variations, gene expression, microbiome, neoantigens, immune infiltrates, and other features. We developed a searchable, web-based interface (the GCR Genome Explorer) to enable researchers access to these datasets.The GCR is a unique, North American GC registry which integrates clinical and genomic annotation.Available for researchers through an open access, web-based explorer, the GCR Genome Explorer will accelerate collaborative GC research across the United States and world.

    View details for DOI 10.1158/1055-9965.EPI-22-0308

    View details for PubMedID 35771165

  • A Comparison of Logistic Regression Against Machine Learning Algorithms for Gastric Cancer Risk Prediction Within Real-World Clinical Data Streams. JCO clinical cancer informatics Huang, R. J., Kwon, N. S., Tomizawa, Y., Choi, A. Y., Hernandez-Boussard, T., Hwang, J. H. 2022; 6: e2200039


    Noncardia gastric cancer (NCGC) is a leading cause of global cancer mortality, and is often diagnosed at advanced stages. Development of NCGC risk models within electronic health records (EHR) may allow for improved cancer prevention. There has been much recent interest in use of machine learning (ML) for cancer prediction, but few studies comparing ML with classical statistical models for NCGC risk prediction.We trained models using logistic regression (LR) and four commonly used ML algorithms to predict NCGC from age-/sex-matched controls in two EHR systems: Stanford University and the University of Washington (UW). The LR model contained well-established NCGC risk factors (intestinal metaplasia histology, prior Helicobacter pylori infection, race, ethnicity, nativity status, smoking history, anemia), whereas ML models agnostically selected variables from the EHR. Models were developed and internally validated in the Stanford data, and externally validated in the UW data. Hyperparameter tuning of models was achieved using cross-validation. Model performance was compared by accuracy, sensitivity, and specificity.In internal validation, LR performed with comparable accuracy (0.732; 95% CI, 0.698 to 0.764), sensitivity (0.697; 95% CI, 0.647 to 0.744), and specificity (0.767; 95% CI, 0.720 to 0.809) to penalized lasso, support vector machine, K-nearest neighbor, and random forest models. In external validation, LR continued to demonstrate high accuracy, sensitivity, and specificity. Although K-nearest neighbor demonstrated higher accuracy and specificity, this was offset by significantly lower sensitivity. No ML model consistently outperformed LR across evaluation criteria.Drawing data from two independent EHRs, we find LR on the basis of established risk factors demonstrated comparable performance to optimized ML algorithms. This study demonstrates that classical models built on robust, hand-chosen predictor variables may not be inferior to data-driven models for NCGC risk prediction.

    View details for DOI 10.1200/CCI.22.00039

    View details for PubMedID 35763703

  • ALTEN: A High-Fidelity Primary Tissue-Engineering Platform to Assess Cellular Responses Ex Vivo. Advanced science (Weinheim, Baden-Wurttemberg, Germany) Law, A. M., Chen, J., Colino-Sanguino, Y., Fuente, L. R., Fang, G., Grimes, S. M., Lu, H., Huang, R. J., Boyle, S. T., Venhuizen, J., Castillo, L., Tavakoli, J., Skhinas, J. N., Millar, E. K., Beretov, J., Rossello, F. J., Tipper, J. L., Ormandy, C. J., Samuel, M. S., Cox, T. R., Martelotto, L., Jin, D., Valdes-Mora, F., Ji, H. P., Gallego-Ortega, D. 2022: e2103332


    To fully investigate cellular responses to stimuli and perturbations within tissues, it is essential to replicate the complex molecular interactions within the local microenvironment of cellular niches. Here, the authors introduce Alginate-based tissue engineering (ALTEN), a biomimetic tissue platform that allows ex vivo analysis of explanted tissue biopsies. This method preserves the original characteristics of the source tissue's cellular milieu, allowing multiple and diverse cell types to be maintained over an extended period of time. As a result, ALTEN enables rapid and faithful characterization of perturbations across specific cell types within a tissue. Importantly, using single-cell genomics, this approach provides integrated cellular responses at the resolution of individual cells. ALTEN is a powerful tool for the analysis of cellular responses upon exposure to cytotoxic agents and immunomodulators. Additionally, ALTEN's scalability using automated microfluidic devices for tissue encapsulation and subsequent transport, to enable centralized high-throughput analysis of samples gathered by large-scale multicenter studies, is shown.

    View details for DOI 10.1002/advs.202103332

    View details for PubMedID 35611998

  • Leading causes of death in Asian Indians in the United States (2005-2017). PloS one Fernandez Perez, C., Xi, K., Simha, A., Shah, N. S., Huang, R. J., Palaniappan, L., Chung, S., Au, T., Sharp, N., Islas, N., Srinivasan, M. 2022; 17 (8): e0271375


    OBJECTIVE: Asian Indians are among the fastest growing United States (US) ethnic subgroups. We characterized mortality trends for leading causes of death among foreign-born and US-born Asian Indians in the US between 2005-2017.STUDY DESIGN AND SETTING: Using US standardized death certificate data, we examined leading causes of death in 73,470 Asian Indians and 20,496,189 non-Hispanic whites (NHWs) across age, gender, and nativity. For each cause, we report age-standardized mortality rates (AMR), longitudinal trends, and absolute percent change (APC).RESULTS: We found that Asian Indians' leading causes of death were heart disease (28% mortality males; 24% females) and cancer (18% males; 22% females). Foreign-born Asian Indians had higher all-cause AMR compared to US-born (AMR 271 foreign-born, CI 263-280; 175.8 US-born, CI 140-221; p<0.05), while Asian Indian all-cause AMR was lower than that of NHWs (AMR 271 Indian, CI 263-278; 754.4 NHW, CI 753.3-755.5; p<0.05). All-cause AMR increased for foreign-born Asian Indians over time, while decreasing for US-born Asian Indians and NHWs.CONCLUSIONS: Foreign-born Asian Indians were 2.2 times more likely to die of heart disease and 1.6 times more likely to die of cancer. Asian Indian male AMR was 49% greater than female on average, although AMR was consistently lower for Asian Indians when compared to NHWs.

    View details for DOI 10.1371/journal.pone.0271375

    View details for PubMedID 35947608

  • The risk of diffuse-type gastric cancer following diagnosis with gastric precancerous lesions: a systematic review and meta-analysis. Cancer causes & control : CCC Wang, J. E., Kim, S. E., Lee, B. E., Park, S., Hwang, J. H., Huang, R. J. 2021


    PURPOSE: Gastric cancers are classified as diffuse-type (DTGC) or intestinal-type (ITGC). DTGCs have distinct clinical and histopathologic features, and carry a worse overall prognosis compared to ITGCs. Atrophic gastritis (AG) and intestinal metaplasia (IM) are known precursors to ITGC. It is unknown if AG and IM increase risk for DTGC.METHODS: We performed a systematic review to identify studies reporting on the association of AG/IM and DTGC. We extracted the odds ratio (OR) of the association from studies, and performed pool analysis. Subgroup analysis was performed on studies reporting histologic severity (using operative link systems) to assess if histologic severity of AG/IM was associated with higher risk.RESULTS: We identified six case-control and eight cohort studies for inclusion. Both AG (pooled OR=1.9, 95% CI 1.5 to 2.4, p<0.001) and IM (pooled OR=2.3, 95% CI 1.9 to 2.9, p<0.001) demonstrated an association with DTGC. High AG severity was associated with increased risk for DTGC compared to low AG severity (OR=1.7, 95% CI 1.2 to 2.3, p=0.002). Similarly, high IM severity was associated with increased risk compared to low IM severity (OR=1.9, 95% CI 1.3 to 2.7, p=0.001).CONCLUSION: Both AG and IM are associated with DTGC. Increasing histologic severity of both AG and IM increases risk for DTGC. There may exist a common pathway between ITGC and some DTGCs mediated through mucosal precursor lesions. These data may inform future strategies of cancer risk attenuation and control.

    View details for DOI 10.1007/s10552-021-01522-1

    View details for PubMedID 34797436

  • Diverging Patterns of Cardia and Non-Cardia Gastric Adenocarcinoma Incidence by Race and Age in the United States From 2000-2018 Kim, S., Huang, R. J., Hwang, J. LIPPINCOTT WILLIAMS & WILKINS. 2021: S635-S636
  • Impact of Race and Ethnicity on Risks of Cardia and Non-Cardia Gastric Adenocarcinomas in the US, 2000-2019: A Large Single-Center Retrospective Cohort Study Kim, S., Hwang, J., Huang, R. J., Kwon, S., Park, S., Choi, C., Lee, B. LIPPINCOTT WILLIAMS & WILKINS. 2021: S635
  • Improving the Early Diagnosis of Gastric Cancer. Gastrointestinal endoscopy clinics of North America Huang, R. J., Hwang, J. H. 2021; 31 (3): 503-517


    Gastric cancer (GC) remains a leading cause of cancer morbidity and mortality worldwide. Outcomes from GC remain poor, especially in Western nations where cancer diagnosis is usually at advanced stages where curative resection is not possible. By contrast, nations of East Asia have adopted methods of population-level screening with improvements in stage of diagnosis and survival. In this review, the authors discuss the epidemiology of GC in Western populations, highlight at-risk populations who may benefit from screening, overview screening modalities, and discuss promising approaches to early GC detection.

    View details for DOI 10.1016/j.giec.2021.03.005

    View details for PubMedID 34053636

  • Reply to Letter to the Editor. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association Huang, R., Hwang, J. H. 2021

    View details for DOI 10.1016/j.cgh.2021.03.010

    View details for PubMedID 33716138

  • Disaggregated Mortality from Gastrointestinal Cancers in Asian Americans: Analysis of United States Death Records. International journal of cancer Huang, R. J., Sharp, N., Talamoa, R., Kapphahn, K., Sathye, V., Lin, B., Srinivasan, M., Palaniappan, L. P. 2021


    Asian Americans (AAs) are heterogeneous, and aggregation of diverse AA populations in national reporting may mask high-risk groups. Gastrointestinal (GI) cancers constitute one-third of global cancer mortality, and an improved understanding of GI cancer mortality by disaggregated AA subgroups may inform future primary and secondary prevention strategies. Using national mortality records from the United States from 2003-2017, we report age-standardized mortality rates, standardized mortality ratios, and annual percent change trends from GI cancers (esophageal, gastric, colorectal, liver, and pancreatic) for the six largest AA subgroups (Asian Indians, Chinese, Filipinos, Japanese, Koreans and Vietnamese). Non-Hispanic Whites (NHWs) are used as the reference population. We found that mortality from GI cancers demonstrated nearly 3-fold difference between the highest (Koreans, 61 per 100 000 person-years) and lowest (Asian Indians, 21 per 100 000 person-years) subgroups. The distribution of GI cancer mortality demonstrates high variability between subgroups, with Korean Americans demonstrating high mortality from gastric cancer (16 per 100 000), and Vietnamese Americans demonstrating high mortality from liver cancer (19 per 100 000). Divergent temporal trends emerged, such as increasing liver cancer burden in Vietnamese Americans, which exacerbated existing mortality differences. There exist striking differences in the mortality burden of GI cancers by disaggregated AA subgroups. These data highlight the need for disaggregated data reporting, and the importance of race-specific and personalized strategies of screening and prevention. This article is protected by copyright. All rights reserved.

    View details for DOI 10.1002/ijc.33490

    View details for PubMedID 33527405

  • Quality metrics in the performance of EUS: a population-based observational cohort of the United States. Gastrointestinal endoscopy Huang, R. J., Barakat, M. T., Park, W. n., Banerjee, S. n. 2021


    There exist few data on the quality of endoscopic ultrasound (EUS) in the community setting. We characterized EUS performance at the individual facility level in 3 large American states, using need for repeat biopsy (NRB) as a metric for procedural failure, and rate of unplanned hospital encounter (UHE) as a metric for adverse event.We collected data on 76,614 EUS procedures performed at 166 facilities in California, Florida, and New York (2009-2014). The endpoints for the study were 7-day rate of UHE after EUS, and 30-day rate of NRB after EUS with fine-needle aspiration. Facility-level factors analyzed included annual procedure volume, urban/rural location, and free-standing status (facilities not attached to a larger hospital). Predictors for UHE and NRB were analyzed in both multivariable regression and nonparametric local regression.Facility volume did not predict risk for UHE. However, high facility volume protected against NRB (p-trend <0.001) even after adjustment for other facility-level factors. When regressing facility volume against risk for NRB in local regression, a join-point (inflection point) was identified at 97 procedures per annum. Once facilities reached this threshold volume, there appeared little additional protective effect of higher volume. Rural facility location (OR, 1.81; 95% CI, 1.36-2.40) and free-standing status (OR, 1.57; 95% CI, 1.16-2.13) also associated with NRB.Facility volume does not predict risk for adverse events after EUS. However, high facility volume is associated with decreased rates of technical failure (as assessed by NRB). These data provide one of the first descriptions of EUS practice in community settings and highlight opportunities to improve endoscopic quality nationally.

    View details for DOI 10.1016/j.gie.2020.12.055

    View details for PubMedID 33476611

  • An Approach to the Primary and Secondary Prevention of Gastric Cancer in the United States. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association Huang, R. J., Epplein, M., Hamashima, C., Choi, I. J., Lee, E., Deapen, D., Woo, Y., Tran, T., Shah, S. C., Inadomi, J. M., Greenwald, D. A., Hwang, J. H. 2021


    /Aims: Gastric cancer (GC) remains a leading cause of mortality among certain racial, ethnic, and immigrant groups in the United States (US). The majority of GCs are diagnosed at advanced stages, and overall survival remains poor. There exist no structured national strategies for GC prevention in the US.On March 5-6, 2020 a Summit of researchers, policy makers, public funders, and advocacy leaders was convened at Stanford University to address this critical healthcare disparity. Following this Summit, a writing group was formed to critically evaluate the effectiveness, potential benefits, and potential harms of methods of primary and secondary prevention through structured literature review. This White Paper represents a consensus statement prepared by the writing group.The burden of GC is highly inequitably distributed in the US, and disproportionately falls on Asian, African American, Hispanic, and American Indian/Alaskan Native populations. In randomized controlled trials, strategies of Helicobacter pylori testing and treatment have been demonstrated to reduce GC-specific mortality. In well-conducted observational and ecological studies, strategies of endoscopic screening have been associated with reduced GC-specific mortality. Notably however, all randomized controlled trial data (for primary prevention), and the majority of observational data (for secondary prevention) are derived from non-US sources.There exists substantial, high-quality data supporting GC prevention derived from international studies. There is an urgent need for cancer prevention trials focused on high-risk immigrant and minority populations in the US. The authors offer recommendations on how strategies of primary and secondary prevention can be applied to the heterogeneous US population.

    View details for DOI 10.1016/j.cgh.2021.09.039

    View details for PubMedID 34624563

  • Pepsinogens and Gastrin Demonstrate Low Discrimination for Gastric Precancerous Lesions in a Multi-Ethnic United States Cohort. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association Huang, R. n., Park, S. n., Shen, J. n., Longacre, T. n., Ji, H. n., Hwang, J. H. 2021

    View details for DOI 10.1016/j.cgh.2021.01.009

    View details for PubMedID 33434656

  • A Summary of the 2020 Gastric Cancer Summit at Stanford University. Gastroenterology Huang, R. J., Koh, H., Hwang, J. H., Summit Leaders, Abnet, C. C., Alarid-Escudero, F., Amieva, M. R., Bruce, M. G., Camargo, M. C., Chan, A. T., Choi, I. J., Corvalan, A., Davis, J. L., Deapen, D., Epplein, M., Greenwald, D. A., Hamashima, C., Hur, C., Inadomi, J. M., Ji, H. P., Jung, H., Lee, E., Lin, B., Palaniappan, L. P., Parsonnet, J., Peek, R. M., Piazuelo, M. B., Rabkin, C. S., Shah, S. C., Smith, A., So, S., Stoffel, E. M., Umar, A., Wilson, K. T., Woo, Y., Yeoh, K. G. 2020

    View details for DOI 10.1053/j.gastro.2020.05.100

    View details for PubMedID 32707045

  • A case-control study of risk factors for advanced gastric intestinal metaplasia in a multiethnic United States population (The Stanford GAPS Study) Huang, R. J., Park, S., Chitre, T., Shen, J., Longacre, T., Ha Hwang, J. AMER ASSOC CANCER RESEARCH. 2020
  • Regional disparities in gastric cancer survival in the United States: An observational cohort study of the Surveillance Epidemiology and End Results Program, 2004-2016 Huang, R., Hsing, A., Palaniappan, L., Hwang, J. AMER ASSOC CANCER RESEARCH. 2020
  • Disaggregation of gastric cancer risk Between Asian American subgroups Huang, R. J., Hwang, J., Hsing, A., Palaniappan, L. AMER ASSOC CANCER RESEARCH. 2020
  • County Rurality and Socioeconomic Deprivation is Associated with Reduced Survival from Gastric Cancer in the United States. Gastroenterology Huang, R. J., Shah, S. C., Camargo, M. C., Palaniappan, L., Hwang, J. H. 2020

    View details for DOI 10.1053/j.gastro.2020.05.006

    View details for PubMedID 32387539

  • The Management of Gastric Intestinal Metaplasia in the United States - A Controversial Topic. Gastroenterology Huang, R. J., Hwang, J. H. 2020

    View details for DOI 10.1053/j.gastro.2020.02.066

    View details for PubMedID 32234304

  • Goff Septotomy Is a Safe and Effective Salvage Biliary Access Technique Following Failed Cannulation at ERCP. Digestive diseases and sciences Barakat, M. T., Girotra, M., Huang, R. J., Choudhary, A., Thosani, N. C., Kothari, S., Sethi, S., Banerjee, S. 2020


    BACKGROUND: Biliary cannulation is readily achieved in>85% of patients undergoing endoscopic retrograde cholangiopancreatography (ERCP). When standard cannulation techniques fail, salvage techniques utilized include the needle knife precut, double wire technique, and Goff septotomy.METHODS: Records of patients undergoing ERCP from 2005 to 2016 were retrospectively examined using a prospectively maintained endoscopy database. Patients requiring salvage techniques for biliary access were analyzed together with a control sample of 20 randomly selected index ERCPs per study year. Demographic and clinical variables including indications for ERCP, cannulation rates, and adverse events were collected.RESULTS: A total of 7984 patients underwent ERCP from 2005 to 2016. Biliary cannulation was successful in 94.9% of control index ERCPs, 87.2% of patients who underwent Goff septotomy (significantly higher than for all other salvage techniques, p≤0.001), 74.5% of patients in the double wire group and 69.6% of patients in the needle knife precut group. Adverse event rates were similar in the Goff septotomy (4.1%) and index ERCP control sample (2.7%) groups. Adverse events were significantly higher in the needle knife group (27.2%) compared with all other groups.CONCLUSIONS: This study represents the largest study to date of Goff septotomy as a salvage biliary access technique. It confirms the efficacy of Goff septotomy and indicates a safety profile similar to standard cannulation techniques and superior to the widely employed needle knife precut sphincterotomy. Our safety and efficacy data suggest that Goff septotomy should be considered as the primary salvage approach for failed cannulation, with needle knife sphincterotomy restricted to Goff septotomy failures.

    View details for DOI 10.1007/s10620-020-06124-6

    View details for PubMedID 32052216

  • Risk of ambulatory colonoscopy in patients with cirrhosis: a propensity-score matched cohort study. Endoscopy international open Huang, R. J., Banerjee, S. n., Friedland, S. n., Ladabaum, U. n. 2020; 8 (10): E1495–E1501


    Background and study aims  Patients with cirrhosis demonstrate alterations in physiology, hemodynamics, and immunity which may increase procedural risk. There exist sparse data regarding the safety of performing ambulatory colonoscopy in patients with cirrhosis. Patients and methods  From a population-based sample of three North American states (California, Florida, and New York), we collected data on 3,590 patients with cirrhosis who underwent ambulatory colonoscopy from 2009 to 2014. We created a control cohort propensity score-matched for cirrhotic severity who did not undergo colonoscopy (N = 3,590) in order to calculate the attributable risk for adverse events. The primary endpoint was the rate of unplanned hospital encounters (UHEs) within 14 days of colonoscopy (or from a synthetic index date for the control cohort). Predictors for UHE were assessed in multivariable regression. Results  The attributable risk for any UHE following colonoscopy was 3.1 % (confidence interval [CI] 2.1-4.1 %, P  < 0.001). There was increased risk for infection (0.9 %, CI 0.7-1.1 %), spontaneous bacterial peritonitis (0.1 %, CI 0.0-0.3 %), decompensation of ascites (0.3 %, CI 0.2-0.4 %), and cardiovascular event (0.4 %, CI 0.3-0.5 %). There was no increased attributable risk for gastrointestinal bleeding, perforation, or development of the hepatorenal syndrome. The presence of ascites at time of procedure was the only predictor for UHE in the fully-adjusted model (OR 2.6, CI 1.9-3.5, P  < 0.001). Conclusions  There is a moderate though detectable increase in risk for adverse event following ambulatory colonoscopy in patients with cirrhosis. The presence of ascites in particular portends higher risk. These data may guide clinicians when counseling patients with cirrhosis on the choice of colorectal cancer screening modality.

    View details for DOI 10.1055/a-1242-9958

    View details for PubMedID 33043119

    View details for PubMedCentralID PMC7541192

  • One Size Does Not Fit All: Marked Heterogeneity in Incidence of and Survival from Gastric Cancer among Asian American Subgroups. Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology Huang, R. J., Sharp, N. n., Talamoa, R. O., Ji, H. P., Hwang, J. H., Palaniappan, L. P. 2020


    Asian Americans are at higher risk for non-cardia gastric cancers (NCGCs) relative to non-Hispanic Whites (NHWs). Asian Americans are genetically, linguistically, and culturally heterogeneous, yet have mostly been treated as a single population in prior studies. This aggregation may obscure important subgroup-specific cancer patterns.We utilized data from 13 regional United States cancer registries from 1990-2014 to determine secular trends in incidence and survivorship from NCGC. Data were analyzed for NHWs and the six largest Asian American subgroups: Chinese, Japanese, Filipino, Korean, Vietnamese, and South Asian (Indian/Pakistani).There exists substantial heterogeneity in NCGC incidence between Asian subgroups, with Koreans (48.6 per 100,000 person-years) having seven-fold higher age-adjusted incidence than South Asians (7.4 per 100,000 person-years). Asians had generally earlier stages of diagnosis and higher rates of surgical resection compared to NHWs. All Asian subgroups also demonstrated higher five-year observed survival compared to NHWs, with Koreans (41.3%) and South Asians (42.8%) having survival double that of NHWs (20.1%, p<0.001). In multivariable regression, differences in stage of diagnosis and rates of resection partially explained the difference in survivorship between Asian subgroups.We find substantial differences in incidence, staging, histology, treatment, and survivorship from NCGC between Asian subgroups, data which challenge our traditional perceptions about gastric cancer in Asians. Both biological heterogeneity and cultural/environmental differences may underlie these findings.These data are relevant to the national discourse regarding the appropriate role of gastric cancer screening, and identifies high-risk racial/ethnic subgroups who many benefit from customized risk attenuation programs.

    View details for DOI 10.1158/1055-9965.EPI-19-1482

    View details for PubMedID 32152216

  • Single cell genomic characterization reveals the cellular reprogramming of the gastric tumor microenvironment. Clinical cancer research : an official journal of the American Association for Cancer Research Sathe, A. n., Grimes, S. M., Lau, B. T., Chen, J. n., Suarez, C. n., Huang, R. J., Poultsides, G. A., Ji, H. P. 2020


    The tumor microenvironment (TME) consists of a heterogenous cellular milieu that can influence cancer cell behavior. Its characteristics havean impact on treatments such as immunotherapy. These features can be revealed with single-cell RNA sequencing (scRNA-seq). We hypothesized that scRNA-seq analysis ofgastric cancer (GC) together with paired normal tissue and peripheral blood mononuclear cells (PBMCs) would identify critical elements of cellular deregulation not apparent with other approaches.scRNA-seq was conducted on seven patients with GC and one patient with intestinal metaplasia. We sequenced 56,167 cells comprising GC (32,407 cells), paired normal tissue (18,657 cells) and PBMCs (5,103 cells). Protein expression was validated by multiplex immunofluorescence.Tumor epithelium had copy number alterations, a distinct gene expression program from normal, with intra-tumor heterogeneity. GC TME was significantly enriched for stromal cells, macrophages, dendritic cells (DCs) and Tregs. TME-exclusive stromal cells expressed distinct extracellular matrix components than normal. Macrophages were transcriptionally heterogenous and did not conform to a binary M1/M2 paradigm. Tumor-DCs had a unique gene expression program compared to PBMC DCs. TME-specific cytotoxic T cells were exhausted with two heterogenous subsets. Helper, cytotoxic T, Treg and NK cells expressed multiple immune checkpoint or costimulatory molecules. Receptor-ligand analysis revealed TME-exclusive inter-cellular communication.Single-cell gene expression studies revealed widespread reprogramming across multiple cellular elements in the GC TME. Cellular remodeling was delineated by changes in cell numbers, transcriptional states and inter-cellular interactions. This characterization facilitates understanding of tumor biology and enables identification of novel targets including for immunotherapy.

    View details for DOI 10.1158/1078-0432.CCR-19-3231

    View details for PubMedID 32060101

  • Risk Factors for Advanced Gastric Intestinal Metaplasia in a Multi-Ethnic United States Cohort Huang, R., Park, S., Chitre, T., Shen, J., Longacre, T., Hwang, J. LIPPINCOTT WILLIAMS & WILKINS. 2019: S689–S690
  • Disaggregation of Gastric Cancer Risk Between Asian American Subgroups Huang, R., Hwang, J., Palaniappan, L. LIPPINCOTT WILLIAMS & WILKINS. 2019: S688–S689
  • Diagnosis and Management of Gastric Intestinal Metaplasia: Current Status and Future Directions. Gut and liver Huang, R. J., Choi, A. Y., Truong, C. D., Yeh, M. M., Hwang, J. H. 2019


    Gastric intestinal metaplasia (GIM) is a known premalignant condition of the human stomach along the pathway to gastric cancer (GC). Histologically, GIM represents the replacement of normal gastric mucosa by mucin-secreting intestinal mucosa. Helicobacter pylori infection is the most common etiologic agent of GIM development worldwide. The prevalence of GIM is heterogeneous among different regions of the world and correlates with the population endemicity of H. pylori carriage, among other environmental factors. GC remains the third leading cause of cancer-related mortality globally. GIM is usually diagnosed by upper endoscopy with biopsy, and histologic scoring systems have been developed to risk-stratify patients at highest risk for progression to GC. Several recent endoscopic imaging modalities may improve the optical detection of GIM and early GC. Appropriate surveillance of GIM may be cost effective and represents an opportunity for the early diagnosis and therapy of GC. Certain East Asian nations have established population-level programs for the screening and surveillance of GIM; guidelines regarding GIM surveillance have also recently been published in Europe. By contrast, few data exist regarding the appropriateness of surveillance of GIM in the United States. In this review, we discuss the pathogenesis, epidemiology, diagnosis, and management of GIM with an emphasis on the role of appropriate endoscopic surveillance.

    View details for DOI 10.5009/gnl19181

    View details for PubMedID 31394893

  • A Chance to Cut Is a Chance to Cure: Endoscopic Submucosal Dissection for Early Gastric Cancer DIGESTIVE DISEASES AND SCIENCES Huang, R. J., Charville, G. W., Hwang, J., Friedland, S. 2019; 64 (5): 1129–32
  • Unplanned Hospital Encounters After Endoscopic Retrograde Cholangiopancreatography in 3 Large North American States GASTROENTEROLOGY Huang, R. J., Barakat, M. T., Girotra, M., Lee, J. S., Banerjee, S. 2019; 156 (1): 119-+
  • ASGE review of adverse events in colonoscopy. Gastrointestinal endoscopy Kothari, S. T., Huang, R. J., Shaukat, A. n., Agrawal, D. n., Buxbaum, J. L., Abbas Fehmi, S. M., Fishman, D. S., Gurudu, S. R., Khashab, M. A., Jamil, L. H., Jue, T. L., Law, J. K., Lee, J. K., Naveed, M. n., Qumseya, B. J., Sawhney, M. S., Thosani, N. n., Yang, J. n., DeWitt, J. M., Wani, S. n. 2019


    Colonoscopy is the most commonly performed endoscopic procedure and overall is considered a low-risk procedure. However, adverse events (AEs) related to this routinely performed procedure for screening, diagnostic, or therapeutic purposes are an important clinical consideration. The purpose of this document from the American Society for Gastrointestinal Endoscopy's Standards of Practice Committee is to provide an update on estimates of AEs related to colonoscopy in an evidence-based fashion. A systematic review and meta-analysis of population-based studies was conducted for the 3 most common and important serious AEs (bleeding, perforation, and mortality). In addition, this document includes an updated systematic review and meta-analysis of serious AEs (bleeding and perforation) related to EMR and endoscopic submucosal dissection for large colon polyps. Finally, a narrative review of other colonoscopy-related serious AEs and those related to specific colonic interventions is included.

    View details for DOI 10.1016/j.gie.2019.07.033

    View details for PubMedID 31563271

  • Prevalence, Risk Factors, and Surveillance Patterns for Gastric Intestinal Metaplasia Among Patients Undergoing Upper Endoscopy with Biopsy. Gastrointestinal endoscopy Huang, R. J., Ende, A. R., Singla, A. n., Higa, J. T., Choi, A. Y., Lee, A. B., Whang, S. G., Gravelle, K. n., D'Andrea, S. n., Bang, S. J., Schmidt, R. A., Yeh, M. M., Hwang, J. H. 2019


    Gastric intestinal metaplasia (GIM) is an important precursor lesion to gastric cancer (GC), the second leading cause of cancer deaths worldwide. There exist few data regarding the prevalence of, risk factors for, and clinical practice patterns regarding gastric intestinal metaplasia (GIM) in the United States. Furthermore, there are currently no U.S. guidelines regarding screening/surveillance for GIM.All consecutive upper endoscopic procedures from 2 academic medical centers in Seattle between 1999 and 2014 are reviewed. Demographic, clinical, and endoscopic covariates are recorded at time of endoscopy. Procedures with gastric biopsy are matched to final histologic diagnoses, including presence of Helicobacter pylori. Cases of GIM and dysplasia are recorded and compared with non-GIM controls using univariate and multivariable regression. Surveillance patterns for cases of GIM are recorded.Data from 36,799 upper endoscopies, 17,710 gastric biopsies, 2,073 cases of GIM, 43 cases of dysplasia, and 78 cases of GC were captured. The point prevalence of GIM is 11.7% in patients who underwent gastric biopsy. Non-white race (P<0.001), increasing age (P<0.001), and presence of H pylori (P<0.001) associated with GIM. Once GIM is present, increasing age (P<0.001) and male gender (P<0.001) associate with progression, and presence of H pylori (P<0.001) inversely associates with progression to dysplasia/GC. Few cases of GIM/dysplasia/GC are made during procedures for GIM screening/surveillance. Only 16% of patients with a diagnosis of GIM received a recommendation for surveillance.There is a high prevalence of GIM among non-white and Hispanic Americans. Risk factors for development of GIM may be distinct from risk factors for progression to GC.

    View details for DOI 10.1016/j.gie.2019.07.038

    View details for PubMedID 31425693

  • Routine gastric biopsies: Should we be doing more? Gastrointestinal endoscopy Huang, R. J., Hwang, J. H. 2019; 89 (6): 1150–51

    View details for DOI 10.1016/j.gie.2019.02.010

    View details for PubMedID 31104747

  • Recent Trends and the Impact of the Affordable Care Act on Emergency Department Visits and Hospitalizations for Gastrointestinal, Pancreatic, and Liver Diseases. Journal of clinical gastroenterology Barakat, M. T., Mithal, A., Huang, R. J., Sehgal, A., Sehgal, A., Singh, G., Banerjee, S. 2018


    BACKGROUND: The Affordable Care Act (ACA) with Medicaid expansion implemented in 2014, extended health insurance to >20-million previously uninsured individuals. However, it is unclear whether enhanced primary care access with Medicaid expansion decreased emergency department (ED) visits and hospitalizations for gastrointestinal (GI)/pancreatic/liver diseases.METHODS: We evaluated trends in GI/pancreatic/liver diagnosis-specific ED/hospital utilization over a 5-year period leading up to Medicaid expansion and a year following expansion, in California (a state that implemented Medicaid expansion) and compare these with Florida (a state that did not).RESULTS: From 2009 to 2013, GI/pancreatic/liver disease ED visits increased by 15.0% in California and 20.2% in Florida and hospitalizations for these conditions decreased by 2.6% in California and increased by 7.9% in Florida. Following Medicaid expansion, a shift from self-pay/uninsured to Medicaid insurance was seen California; in addition, a new decrease in ED visits for nausea/vomiting and GI infections, was evident, without associated change in overall ED/hospital utilization trends. Total hospitalization charges for abdominal pain, nausea/vomiting, constipation, and GI infection diagnoses decreased in California following Medicaid expansion, but increased over the same time-period in Florida.CONCLUSIONS: We observed a striking payer shift for GI/pancreatic/liver disease ED visits/hospitalizations after Medicaid expansion in California, indicating a shift in the reimbursement burden in self-pay/uninsured patients, from patients and hospitals to the government. ED visits and hospitalization charges decreased for some primary care-treatable GI diagnoses in California, but not for Florida, suggesting a trend toward lower cost of gastroenterology care, perhaps because of decreased hospital utilization for conditions amenable to outpatient management.

    View details for PubMedID 30285976

  • Unplanned Hospital Encounters Following Endoscopic Retrograde Cholangiopancreatography in 3 Large American States. Gastroenterology Huang, R. J., Barakat, M. T., Girotra, M., Lee, J. S., Banerjee, S. 2018


    BACKGROUND & AIMS: We have few population-level data on the performance of endoscopic retrograde cholangiopancreatography (ERCP) in the United States. We investigated the numbers of unplanned hospital encounters (UHEs), patient and facility factors associated with UHEs, and variation in quality and outcomes in the performance of ERCP in 3 large American states.METHODS: We collected data on 68,642 ERCPs, performed at 635 facilities in California, Florida, and New York from 2009 through 2014. The primary endpoint was number of UHEs with an ERCP-related event within 7 days of ERCP; secondary endpoints included numbers of UHE within 30 days and mortality within 30 days. Each facility was assigned a risk-standardized cohort, and variations in numbers of UHE were analyzed using multivariable analysis.RESULTS: Among all ERCPs, 5.8% resulted in an UHE within 7 days, and 10.2% by 30 days. Performance of sphincterotomy was significantly associated with a higher risk of UHE at 7 and 30 days (P<.001). Younger age, female sex, and more advanced comorbidity associated with UHE. There was substantial heterogeneity in rates of UHE among facilities: 4.2% at facilities in the lower 5th percentile and 25.2% at facilities in the 95th percentile. Increasing facility volume and ability to perform endoscopic ultrasound associated inversely with risk. The median number of ERCPs performed each year was 68.7, but 69% of facilities performed 100 or fewer ERCPs per year. Risk for UHE following sphincterotomy decreased with increasing facility volume until an inflection point of 157 ERCPs per year was reached.CONCLUSIONS: In an analysis of outcomes of 68,642 ERCPs performed in three states, we found a higher than expected number of UHEs. There is substantial unexplained variation in risk for adverse event following ERCPs among facilities-volume is the strongest predictor of risk. Annual facility volumes above approximately 150 ERCPs per year may protect against UHE.

    View details for PubMedID 30243620

  • Chronic pancreatitis changes in high-risk individuals for pancreatic ductal adenocarcinoma. Gastrointestinal endoscopy Thiruvengadam, S. S., Chuang, J., Huang, R., Girotra, M., Park, W. G. 2018


    BACKGROUND AND AIMS: Pancreatic intraepithelial neoplasia is associated with chronic pancreatitis (CP) changes on EUS. The objective of this study was to determine whether CP changes were more common in high-risk individuals (HRIs) than in controls and whether these changes differed among higher-risk subsets of HRIs.METHODS: HRIs and controls were identified from an endoscopy database. HRIs were defined as having predisposing mutations or a family history (FH) of pancreatic ductal adenocarcinoma. HRIs were classified as vHRIs who met cancer of the pancreas screening (CAPS) criteria for high risk and mHRIs who did not. Multivariable logistic regression was used to adjust for confounders and CP risk factors.RESULTS: 65 HRIs (44 vHRIs, 21 mHRIs) and 118 controls were included. HRIs were included for FH (25), Lynch syndrome (5), Peutz-Jeghers syndrome (2), and mutations in BRCA1/2 (26), PALB2 (3), ATM (3), and CDKN2A (1). After adjustment for relevant variables, HRIs were 16 times more likely to exhibit 3 or more CP changes than controls (95% CI, 2.6-97.0; P = .003). HRIs were also more likely to have hypoechoic foci (OR, 8.0; 95% CI, 1.9-32.9; P = .004). vHRIs and mHRIs did not differ in frequency of three or more CP changes on EUS.CONCLUSIONS: HRIs were more likely to exhibit CP changes and hypoechoic foci on EUS compared with controls. HRIs with these findings may require closer surveillance. HRIs who did or did not meet CAPS criteria did not differ with regard to CP findings, supporting a more inclusive approach to screening.

    View details for DOI 10.1016/j.gie.2018.08.029

    View details for PubMedID 30145314

  • Video-based performance assessment in endoscopy: Moving beyond "see one, do one, teach one"? GASTROINTESTINAL ENDOSCOPY Huang, R. J., Limsui, D., Triadafilopoulos, G. 2018; 87 (3): 776–77

    View details for PubMedID 29454450

  • A Chance to Cut Is a Chance to Cure: Endoscopic Submucosal Dissection for Early Gastric Cancer. Digestive diseases and sciences Huang, R. J., Charville, G. W., Hwang, J. H., Friedland, S. n. 2018

    View details for PubMedID 30350240

  • Practice Patterns for Cholecystectomy Following Endoscopic Retrograde Cholangio-Pancreatography for Patients With Choledocholithiasis. Gastroenterology Huang, R. J., Barakat, M. T., Girotra, M., Banerjee, S. 2017


    Cholecystectomy (CCY) following an episode of choledocholithiasis requiring endoscopic retrograde cholangio-pancreatography (ERCP) with stone extraction reduces recurrent biliary events, compared to expectant management. We studied practice patterns for performance of CCY following ERCP for choledocholithiasis using data from 3 large states and evaluated the effects of delaying CCY.We conducted a retrospective cohort study using the ambulatory surgery, inpatient, and emergency department databases from the states of California (years 2009-2011), New York (2011-2013), and Florida (2012-2014). We collected data from 4516 patients hospitalized with choledocholithiasis who underwent ERCP. We compared outcomes of patients who underwent CCY at index admission (early CCY), elective CCY within 60 days of discharge (delayed CCY), or did not undergo CCY (no CCY), calculating rate of recurrent biliary events (defined as an emergency department visit or unplanned hospitalization due to symptomatic cholelithiasis, cholecystitis, choledocholithiasis, cholangitis, or biliary pancreatitis), mortality, and cost by CCY cohort. We also evaluated risk factors for not undergoing CCY. The primary outcome measure was the rate of recurrent biliary events in the 365 days following discharge from index admission.Of the patients who underwent ERCP for choledocholithiasis, 41.2% underwent early CCY, 10.9% underwent delayed CCY, and 48.0% underwent no CCY. Early CCY reduced relative risk of recurrent biliary events within 60 days by 92%, compared with delayed or no CCY (P<.001). After 60 days following discharge from index admission, patients with early CCY had an 87% lower risk of recurrent biliary events than patients with no CCY (P<.001) and patients with delayed CCY had an 88% lower risk of recurrent biliary events than patients with no CCY (P<.001). A strategy of delayed CCY performed on an outpatient basis was least costly. Performance of early CCY was inversely associated with low facility volume. Hispanic race, Asian race, Medicaid insurance, and no insurance associated inversely with performance of delayed CCY.In a retrospective analysis of over 4500 patients hospitalized with choledocholithiasis, we found that CCY was not performed following ERCP for almost half of the cases. Although early and delayed CCY equally reduce the risk of subsequent recurrent biliary events, patients are at 10-fold higher risk of recurrent biliary event while waiting for a delayed CCY compared with patients who underwent early CCY. Delayed CCY is a cost-effective strategy that must be balanced against the risk of loss to follow up, particularly among patients who are ethnic minorities or have little or no health insurance.

    View details for DOI 10.1053/j.gastro.2017.05.048

    View details for PubMedID 28583822

  • The Gastroenterology Fellowship Match: A Decade Later. Digestive diseases and sciences Huang, R. J., Triadafilopoulos, G., Limsui, D. 2017; 62 (6): 1412-1416


    Following a period of uncertainty and disorganization, the gastroenterology (GI) national leadership decided to reinstitute the fellowship match (the Match) under the auspices of the National Residency Matching Program (NRMP) in 2006. Although it has now been a decade since the rebirth of the Match, there have been limited data published regarding progress made. In this piece, we discuss reasons for the original collapse of the GI Match, including most notably a perceived oversupply of GI physicians and a poor job market. We discuss the negative impacts the absence of the Match had on programs and on applicants, as well as the impetus to reorganize the Match under the NRMP. We then utilize data published annually by the NRMP to demonstrate that in the decade since its rebirth, the GI Match has been remarkably successful in terms of attracting the participation of applicants and programs. We show that previous misguided concerns of an oversupply of GI physicians were not realized, and that GI fellowship positions remain highly competitive for internal medicine applicants. Finally, we discuss possible implications of recent changes in the healthcare landscape on the GI Match.

    View details for DOI 10.1007/s10620-017-4593-z

    View details for PubMedID 28474142

    View details for PubMedCentralID PMC5535767

  • Evolution in the utilization of biliary interventions in the United States: results of a nationwide longitudinal study from 1998 to 2013. Gastrointestinal endoscopy Huang, R. J., Thosani, N. C., Barakat, M. T., Choudhary, A., Mithal, A., Singh, G., Sethi, S., Banerjee, S. 2017


    Bile duct surgery (BDS), percutaneous transhepatic cholangiography (PTC), and ERCP are alternative interventions used to treat biliary disease. Our aim was to describe trends in ERCP, BDS, and PTC on a nationwide level in the United States.We used the National Inpatient Sample to estimate age-standardized utilization trends of inpatient diagnostic ERCP, therapeutic ERCP, BDS, and PTC between 1998 and 2013. We calculated average case fatality, length of stay, patient demographic profile (age, gender, payer), and hospital characteristics (hospital size and metropolitan status) for these procedures.Total biliary interventions decreased over the study period from 119.8 to 100.1 per 100,000. Diagnostic ERCP utilization decreased by 76%, and therapeutic ERCP utilization increased by 35%. BDS rates decreased by 78% and PTC rates by 24%. ERCP has almost completely supplanted surgery for the management of choledocholithiasis. Fatality from ERCP, BDS, and PTC have all decreased, whereas mean length of stay has remained stable. The proportion of Medicare-insured, Medicaid-insured, and uninsured patients undergoing biliary procedures has increased over time. Most of the increase in therapeutic ERCP and decrease in BDS occurred in large, metropolitan hospitals.Although therapeutic ERCP utilization has increased over time, the total volume of biliary interventions has decreased. BDS utilization has experienced the most dramatic decrease, possibly a consequence of the increased therapeutic capacity and safety of ERCP. ERCPs are now predominantly therapeutic in nature. Large urban hospitals are leading the shift from surgical to endoscopic therapy of the biliary system.

    View details for DOI 10.1016/j.gie.2016.12.021

    View details for PubMedID 28062313

  • Adenosine triphosphate bioluminescence for bacteriological surveillance and reprocessing strategies for minimizing risk of infection transmission by duodenoscopes. Gastrointestinal endoscopy Sethi, S., Huang, R. J., Barakat, M. T., Banaei, N., Friedland, S., Banerjee, S. 2016


    Recent outbreaks of duodenoscope-transmitted infections underscore the importance of adequate endoscope reprocessing. Adenosine triphosphate (ATP) bioluminescence testing allows rapid evaluation of endoscopes for bacteriologic/biologic residue. In this prospective study we evaluate the utility of ATP in bacteriologic surveillance and the effects of endoscopy staff education and dual cycles of cleaning and high-level disinfection (HLD) on endoscope reprocessing.ATP bioluminescence was measured after precleaning, manual cleaning, and HLD on rinsates from suction-biopsy channels of all endoscopes and elevator channels of duodenoscopes/linear echoendoscopes after use. ATP bioluminescence was remeasured in duodenoscopes (1) after re-education and competency testing of endoscopy staff and subsequently (2) after 2 cycles of precleaning and manual cleaning and single cycle of HLD or (3) after 2 cycles of precleaning, manual cleaning, and HLD.The ideal ATP bioluminescence benchmark of <200 relative light units (RLUs) after manual cleaning was achieved from suction-biopsy channel rinsates of all endoscopes, but 9 of 10 duodenoscope elevator channel rinsates failed to meet this benchmark. Re-education reduced RLUs in duodenoscope elevator channel rinsates after precleaning (23,218.0 vs 1340.5 RLUs, P < .01) and HLD (177.0 vs 12.0 RLUs, P < .01). After 2 cycles of manual cleaning/HLD, duodenoscope elevator channel RLUs achieved levels similar to sterile water, with corresponding negative cultures.ATP testing offers a rapid, inexpensive alternative for detection of endoscope microbial residue. Re-education of endoscopy staff and 2 cycles of cleaning and HLD decreased elevator channel RLUs to levels similar to sterile water and may therefore minimize the risk of transmission of infections by duodenoscopes.

    View details for DOI 10.1016/j.gie.2016.10.035

    View details for PubMedID 27818222

  • Colonoscopy with polypectomy is associated with a low rate of complications in patients with cirrhosis. Endoscopy international open Huang, R. J., Perumpail, R. B., Thosani, N., Cheung, R., Friedland, S. 2016; 4 (9): E947-52


    Cirrhotic patients are at a theoretically increased risk of bleeding. The safety of polypectomy in cirrhosis is poorly defined.We performed a retrospective review of patients with cirrhosis who underwent colonoscopic polypectomy at a tertiary-care hospital. Patient characteristics and polyp data were collected. Development of complications including immediate bleeding, delayed bleeding, hospitalization, blood transfusion, perforation, and death were recorded to 30-day follow-up. Clinical characteristics between bleeders and non-bleeders were compared, and predictors of bleeding were determined.A total of 307 colonoscopies with 638 polypectomies were identified. Immediate bleeding occurred in 7.5 % (95 % CI 4.6 % - 10.4 %) and delayed bleeding occurred in 0.3 % (95 % CI 0.0 % - 0.9 %) of colonoscopies. All cases of immediate bleeding were controlled endoscopically and none resulted in serious complication. The rate of hospitalization was 0.7 % (95 % CI 0.0 % - 1.6 %) and repeat colonoscopy 0.3 % (95 % CI 0.0 % - 0.9 %); no cases of perforation, blood transfusion, or death occurred. Lower platelet count, higher INR, presence of ascites, and presence of esophageal varices were associated with increased risk of bleeding. Use of electrocautery was associated with a lower risk of immediate bleeding. There was no significant difference between bleeding and non-bleeding polyps with regard to size, morphology, and histology.Colonoscopy with polypectomy appears safe in patients with cirrhosis. There is a low risk of major complications. The risk of immediate bleeding appears higher than an average risk population; however, most bleeding is self-limited or can be controlled endoscopically. Bleeding tends to occur with more advanced liver disease. Both the sequelae of portal hypertension and coagulation abnormalities are predictive of bleeding.

    View details for DOI 10.1055/s-0042-111317

    View details for PubMedID 27652299

    View details for PubMedCentralID PMC5025305

  • Response. Gastrointestinal endoscopy Huang, R. J., Draper, K. V., Gerson, L. B. 2015; 81 (3): 777-?

    View details for DOI 10.1016/j.gie.2014.09.056

    View details for PubMedID 25708772

  • Colonic plasmacytomas: a rare complication of plasma cell leukemia. Endoscopy Hang, C. T., Perumpail, R. B., Huang, R. J., Fernandez-Pol, S., Fernandez-Becker, N. Q. 2015; 47: E77-8

    View details for DOI 10.1055/s-0034-1390722

    View details for PubMedID 25926223

  • Locally advanced gastric cancer complicated by mesenteric invasion and intestinal malrotation. Digestive diseases and sciences Huang, R. J., Visser, B. C., Chen, A. M., Ladabaum, U. 2014; 59 (2): 267-269

    View details for DOI 10.1007/s10620-013-2869-5

    View details for PubMedID 24036993

  • Manometric abnormalities in the postural orthostatic tachycardia syndrome: a case series. Digestive diseases and sciences Huang, R. J., Chun, C. L., Friday, K., Triadafilopoulos, G. 2013; 58 (11): 3207-3211


    Postural orthostatic tachycardia syndrome (POTS) is a rare disease that is believed to be mediated by dysautonomia. Gastrointestinal complaints in POTS patients are common and disturbing but not well characterized.We hypothesized that gastrointestinal dysmotility may be contributory to these symptoms.We studied 12 POTS patients who presented with gastrointestinal symptoms to a tertiary referral center. Gastrointestinal symptoms were quantified using a previously validated symptom questionnaire. All patients underwent gastroduodenal manometry (GDM); select patients also underwent further testing including esophageal manometry (EM), anorectal manometry (ARM), plain abdominal radiography (AXR), abdominal computed tomography (CT), gastric emptying studies (GES), and colonic transit time (CTT) studies.The four most common symptoms were bloating, constipation, abdominal pain, and nausea/vomiting, all experienced by greater than 70 % of patients. On GDM testing, 93 % of patients demonstrated signs of neuropathy, and the most common abnormalities observed included bursts of uncoordinated phasic activity in both fasting (59 %) and post-prandial (42 %) states, low contractility in the post-prandial state (67 %), and lack of post-prandial pattern (42 %). A total of 67 % of patients undergoing EM and 86 % of those undergoing ARM demonstrated abnormalities consistent with dysmotility. On AXR or CT, 58 % demonstrated either dilated intestinal loops or air-fluid levels. On CTT 80 % demonstrated delayed colonic transit, while on GES 60 % demonstrated delayed gastric emptying.In this cohort of POTS patients with gastrointestinal symptoms, there is a high prevalence of abnormal manometric and radiographic findings suggestive of dysmotility.

    View details for DOI 10.1007/s10620-013-2865-9

    View details for PubMedID 24068608

  • Acute Fulminant Hepatic Failure Associated with Parvovirus B19 Infection in an Immunocompetent Adult DIGESTIVE DISEASES AND SCIENCES Huang, R. J., Varr, B. C., Triadafilopoulos, G. 2012; 57 (11): 2811-2813

    View details for DOI 10.1007/s10620-012-2110-y

    View details for Web of Science ID 000309867800028

    View details for PubMedID 22395961