Nathan Geonwoo Kim

All Publications

• Yttrium-90 radioembolization is associated with a lower risk of liver transplant waitlist dropout than chemoembolization in hepatocellular carcinoma. Journal of hepatology Kim, N. G., Yao, F. Y., Kwong, A. J., Mehta, N. 2026

  Abstract

  Recent small studies have suggested improved hepatocellular carcinoma (HCC)-related outcomes with trans-arterial radioembolization (TARE) compared to chemoembolization (TACE), although it remains unclear if this leads to superior transplant-related outcomes. Our aim was to compare waitlist outcomes for TARE vs. TACE as first local-regional treatment (LRT) for HCC in the contemporary Median Model for End-Stage Liver Disease (MELD) at Transplant minus 3 (MMaT-3) era with standardized wait times throughout the country.The study cohort comprised of 5677 adult liver transplant candidates from the United Network for Organ Sharing database with at least one approved HCC exception between May 14, 2019 and October 3, 2024, and received first LRT with TACE (50.0%) or TARE (50.0%).The TARE group had a slightly larger proportion of solitary initial tumor (76.4% vs. 70.5%) and median largest tumor size, although aggregate tumor size was similar. The TARE group had a higher proportion receiving only one LRT (80.6% vs. 57.8%) and a higher rate of complete necrosis in the explant (35.3% vs. 20.2%) versus the TACE group. The TARE group had a 22% decreased hazard of waitlist dropout in inverse probability of treatment-weighted competing risk analysis (hazard ratio 0.78, 95% confidence interval 0.69 - 0.89, p<0.001; cumulative incidence at 1 year: 8.9% vs. 11.4%; 2 years: 14.2% vs. 19.0%; 3 years: 16.8% vs. 22.1%) compared to TACE, adjusting for patient and tumor characteristics.In a large national cohort of liver transplant candidates with HCC, TARE compared to TACE as first LRT was associated with higher rates of complete necrosis on explant, lower likelihood of multiple LRTs, and lower risk of waitlist dropout.With nearly all hepatocellular carcinoma (HCC) patients in the US now receiving local regional therapies (LRT), better understanding of the optimal LRT type to achieve tumor control and maintain tumor stage is needed. In this contemporary study of over 5000 patients using the US national database (UNOS), we showed that trans-arterial radioembolization (TARE) may be the preferred bridging therapy over chemoembolization (TACE) based on a significantly lower probability of waitlist dropout after controlling for liver function and tumor characteristics. Additionally, TARE treated patients demonstrated higher probability of complete pathologic response and reduced tumor under-staging on explant, which taken together strongly suggests that TARE is a more effective tumor treatment compared to TACE.

  View details for DOI 10.1016/j.jhep.2026.01.008

  View details for PubMedID 41580092

• YTTRIUM-90 RADIOEMBOLIZATION HAS BECOME THE MOST UTILIZED BRIDGING TREATMENT FOR LIVER TRANSPLANT CANDIDATES IN THE UNITED STATES. Journal of vascular and interventional radiology : JVIR Salem, R., Kwong, A. J., Kim, N., Sze, D. Y., Mehta, N. 2024

  View details for DOI 10.1016/j.jvir.2024.10.034

  View details for PubMedID 39522866

• Identifying Quality Gaps in Preventive Care for Outpatients With Cirrhosis Within a Large, Academic Health Care System. Hepatology communications Kardashian, A., Patel, A. A., Aby, E. S., Cusumano, V. T., Soroudi, C., Winters, A. C., Wu, E., Beah, P., Delshad, S., Kim, N., Yang, L., May, F. P. 2020; 4 (12): 1802-1811

  Abstract

  We sought to identify specific gaps in preventive care provided to outpatients with cirrhosis and to determine factors associated with high quality of care (QOC), to guide quality improvement efforts. Outpatients with cirrhosis who received care at a large, academic tertiary health care system in the United States were included. Twelve quality indicators (QIs), including preventive care processes for ascites, esophageal varices, hepatic encephalopathy, hepatocellular carcinoma (HCC), and general cirrhosis care, were measured. QI pass rates were calculated as the proportion of patients eligible for a QI who received that QI during the study period. We performed logistic regression to determine predictors of high QOC (≥ 75% of eligible QIs) and receipt of HCC surveillance. Of the 439 patients, the median age was 63 years, 59% were male, and 19% were Hispanic. The median Model for End-Stage Liver Disease-Sodium score was 11, 64% were compensated, and 32% had hepatitis C virus. QI pass rates varied by individual QIs, but were overall low. For example, 24% received appropriate HCC surveillance, 32% received an index endoscopy for varices screening, and 21% received secondary prophylaxis for spontaneous bacterial peritonitis. In multivariable analyses, Asian race (odds ratio [OR]: 3.7, 95% confidence interval [CI]: 1.3-10.2) was associated with higher QOC, and both Asian race (OR: 3.3, 95% CI: 1.2-9.0) and decompensated status (OR: 2.1, 95% CI: 1.1-4.2) were associated with receipt of HCC surveillance. A greater number of specialty care visits was not associated with higher QOC. Conclusion: Receipt of outpatient preventive cirrhosis QIs was variable and overall low in a diverse cohort of patients with cirrhosis. Variation in care by race/ethnicity and illness trajectory should prompt further inquiry into identifying modifiable factors to standardize care delivery and to improve QOC.

  View details for DOI 10.1002/hep4.1594

  View details for PubMedID 33305151

  View details for PubMedCentralID PMC7706302

• Cardiovascular and metabolic disease in the liver transplant recipient. Best practice & research. Clinical gastroenterology Kim, N. G., Sharma, A., Saab, S. 2020; 46-47: 101683

  Abstract

  Liver transplantation has led to great improvements in long-term survival in patients with decompensated liver disease and hepatocellular carcinoma. Cardiovascular disease is the leading cause of non-graft-related deaths and has increased prevalence in liver allograft recipients. This is partly secondary to higher post-transplant rates of metabolic risk factors-notably obesity, hypertension, dyslipidemia, and diabetes mellitus, which comprise metabolic syndrome. Post-transplantation metabolic syndrome is expected to be a growing factor in morbidity and mortality as transplant candidates trend older, the rates of metabolic risk factors in the general population increase, non-alcoholic steatohepatitis grows disproportionally as an indication for transplantation, and post-transplantation survival lengthens. This review discusses the incidence and contributory factors for post-transplant increases in metabolic disease, as well as the burden of cardiovascular disease in the liver allograft recipient. Patients with pre-transplant diabetes or obesity are at particularly high risk for post-transplant metabolic syndrome, and would likely benefit from closer surveillance and more aggressive medical management of risk factors. In metabolic disease resistant to initial medical therapies, tailoring of immunosuppressive regimens may further assist in minimizing long-term cardiovascular disease, although this must be done with caution to avoid worsening the risk of graft failure.

  View details for DOI 10.1016/j.bpg.2020.101683

  View details for PubMedID 33158470

• Meeting the WHO hepatitis C virus elimination goal: Review of treatment in paediatrics. Journal of viral hepatitis Kim, N. G., Kullar, R., Khalil, H., Saab, S. 2020; 27 (8): 762-769

  Abstract

  Over 3 million paediatric patients globally and ~50 000 in the United States are estimated to be infected with HCV. Eradicating HCV in children helps prevent liver fibrosis, cirrhosis and hepatocellular carcinoma; reduces extra-hepatic manifestations of HCV; improves quality of life; and increases survival. The 2019 American Association for the Study of Liver Diseases-Infectious Diseases Society of America (AASLD-IDSA) guidelines now recommend direct-acting antiviral (DAA) treatment with an approved regimen for all children and adolescents with HCV infection aged ≥3 years. We conducted a descriptive review of the new DAA treatments for HCV infection in the paediatric population. Ledipasvir/sofosbuvir (LDV/SOF) and sofosbuvir with ribavirin (SOF/RBV) are now approved for those ≥3 years old under specific clinical scenarios; sofosbuvir/velpatasvir (SOF/VEL) is the only pangenotypic agent approved for those ≥6 years or ≥17 kg, and glecaprevir/pibrentasvir (GLE/PIB) is approved for adolescents ≥12 years old or ≥45 kg. These DAA regimens are well-tolerated and have comparable sustained virologic response rates at 12 weeks post-treatment compared to those reported in adults (close to 100%). The introduction of DAAs has significantly changed the landscape of HCV treatment in adults and children with HCV infection and has increased confidence that the 2030 World Health Organization elimination goal may be attainable. Further studies are warranted to determine the optimal treatment for children with HCV infection, including timing, regimen and duration. Additionally, with the recent paediatric approvals, long-term safety data are needed.

  View details for DOI 10.1111/jvh.13317

  View details for PubMedID 32386099

• Practical Tips on TIPS: When and When Not to Request It. The American journal of gastroenterology Saab, S., Kim, N. G., Lee, E. W. 2020; 115 (6): 797-800

  View details for DOI 10.14309/ajg.0000000000000611

  View details for PubMedID 32427674

• Cost Effectiveness of Endoscopic Resection vs Transanal Resection of Complex Benign Rectal Polyps CLINICAL GASTROENTEROLOGY AND HEPATOLOGY Yu, J. X., Russell, W., Ching, J. H., Kim, N., Bendavid, E., Owens, D. K., Kaltenbach, T. 2019; 17 (13): 2740-+

  View details for DOI 10.1016/j.cgh.2019.02.041

  View details for Web of Science ID 000497972200024

• Cost Effectiveness of Endoscopic Resection vs Transanal Resection of Complex Benign Rectal Polyps. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association Yu, J. X., Russell, W. A., Ching, J. H., Kim, N., Bendavid, E., Owens, D. K., Kaltenbach, T. 2019

  Abstract

  BACKGROUND & AIMS: Complex benign rectal polyps can be managed with transanal surgery or with endoscopic resection (ER). Though the complication rate after ER is lower than transanal surgery, recurrence is higher. Patients lost to follow up after ER might therefore be at increased risk for rectal cancer. We evaluated the costs, benefits, and cost effectiveness of ER compared to 2 surgical techniques for removing complex rectal polyps, using a 50-year time horizon-this allowed us to capture rates of cancer development among patients lost from follow-up surveillance.METHODS: We created a Markov model to simulate the lifetime outcomes and costs of ER, transanal endoscopic microsurgery (TEM), and transanal minimally invasive surgery (TAMIS) for the management of a complex benign rectal polyp. We assessed the effect of surveillance by allowing a portion of the patients to be lost to follow up. We calculated the cost, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratio or each intervention over a 50-year time horizon.RESULTS: We found that TEM was slightly more effective than TAMIS and ER (TEM, 19.54 QALYs; TAMIS, 19.53 QALYs; and ER19.53, QALYs), but ER had a lower lifetime discounted cost (ER cost $7161, TEM cost $10,459, and TAMIS cost $11,253). TEM was not cost effective compared to ER, with an incremental cost-effectiveness ratio of $485,333/QALY. TAMIS was ruled out by extended dominance. TEM became cost effective when the mortality from ER exceeded 0.63%, or if loss to follow up exceeded 25.5%.CONCLUSIONS: Using a Markov model, we found that ER, TEM, and TAMIS have similar effectiveness, but ER is less expensive, in management of benign rectal polyps. As the rate of loss to follow up increases, transanal surgery becomes more effective relative to ER.

  View details for PubMedID 30849517

• Immersion medicine programme for secondary students CLINICAL TEACHER Minhas, P. S., Kim, N., Myers, J., Caceres, W., Martin, M., Singh, B. 2018; 15 (5): 370-376

  View details for DOI 10.1111/tct.12694

  View details for Web of Science ID 000445741700004

• Temporal Trends in Disease Presentation and Survival of Patients With Hepatocellular Carcinoma: A Real-World Experience From 1998 to 2015 CANCER Kim, N. G., Nguyen, P. P., Dang, H., Kumari, R., Garcia, G., Esquivel, C. O., Nguyen, M. H. 2018; 124 (12): 2588–98

  View details for DOI 10.1002/cncr.31373

  View details for Web of Science ID 000434350700019

• Temporal trends in disease presentation and survival of patients with hepatocellular carcinoma: A real-world experience from 1998 to 2015. Cancer Kim, N. G., Nguyen, P. P., Dang, H. n., Kumari, R. n., Garcia, G. n., Esquivel, C. O., Nguyen, M. H. 2018

  Abstract

  Hepatocellular carcinoma (HCC) is one of the few cancers whose incidence continues to increase. The goal of the current study was to investigate the presentation and survival trends of patients with HCC presenting to a university hospital between 1998 and 2015.Study data were ascertained by individual chart review with survival data also supplemented by National Death Index query up to December 31, 2015. Patients were divided into three 6-year groups by diagnosis date (1998-2003, 2004-2009, and 2010-2015).A total of 2106 consecutive patients with HCC were included. The majority of patients had either hepatitis C (56.7%) or hepatitis B (22.1%), but cases of nonalcoholic steatohepatitis HCC increased by 68% over the most recent time period. Screening/surveillance identified 61% of HCC cases, but only 31% of these patients underwent curative treatment, which did not increase significantly over time. The overall median survival was 29.8 months (2.48 years) and without improvement over time. On multivariable analysis, Asian or Hispanic ethnicity, meeting Milan criteria, and receiving any of the standard HCC treatments were found to be significantly associated with improved survival, but diagnosis time period and liver disease etiology were not.Over the last 18 years, the percentage of cases of nonalcoholic steatohepatitis HCC has increased but not overall survival. It is interesting to note that only 31% of patients with HCC identified via screening/surveillance received any curative treatment. Further research is needed to better understand the barriers to curative care for patients with HCC and the causes of the lack of improvement in survival in the more recent patient cohort. Cancer 2018. © 2018 American Cancer Society.

  View details for PubMedID 29624631

• Donor Age and Allograft Survival in Recipients with Hepatitis C Virus in the Direct-Acting Antiviral Era Kwong, A. J., Kim, N. G., Stoltz, D., Mannalithara, A., Kim, W. WILEY. 2017: 886A–887A

  View details for Web of Science ID 000412089802019

• Cost Effectiveness of Endoscopic Mucosal Resection Compared to Transanal Resection of Complex Rectal Polyps Yu, J. X., Russell, W. A., Kim, N. G., Ching, J., Bendavid, E., Owens, D. K., Kaltenbach, T. R. MOSBY-ELSEVIER. 2017: AB371

  View details for DOI 10.1016/j.gie.2017.03.858

  View details for Web of Science ID 000403087401055

• Increased Prevalence of Metabolic Risk Factors in Asian Americans With Hepatocellular Carcinoma. Journal of clinical gastroenterology Kutsenko, A., Ladenheim, M. R., Kim, N., Nguyen, P., Chen, V., Jayasekera, C., Yang, J. D., Kumari, R., Roberts, L., Nguyen, M. H. 2017; 51 (4): 384-390

  Abstract

  We used metabolic risk factors to estimate the prevalence and clinical significance of nonalcoholic fatty liver disease in Asian Americans with hepatocellular carcinoma (HCC).This is a retrospective cohort study of 824 consecutive Asian HCC patients at Stanford University Medical Center from 1998 to 2015. Patients were subdivided as: Chinese, other East Asian (Japanese and Korean), South East Asian (Vietnamese, Thai, and Laotian), Maritime South East Asian (MSEA: Malaysian, Indonesian, Filipino, and Singaporean), and South West Asian (Indian, Pakistani, and Middle Eastern). Metabolic risk factors studied were body mass index, hypertension, type II diabetes, and hyperlipidemia.Most patients were male (76%) with mean age 63 years. Metabolic risk factors were highly prevalent on presentation and increased over time (P<0.001), as did the prevalence of cryptogenic HCC (P<0.004). Compared with other Asian subgroups, MSEAs had the highest body mass index (26.3) and higher rates of type II diabetes (44% vs. 23% to 35%, P=0.004), hypertension (59% vs. 38% to 55%, P=0.04), and cryptogenic HCC (15% vs. 4% to 10%, P=0.01). They were more likely to be symptomatic on presentation (44% vs. 32% to 58%, P=0.07), less likely to present within Milan criteria (34% vs. 35% to 63%, P<0.0001), and trended toward decreased 10-year survival rates compared with other ethnic subgroups (9% vs. 25% to 32%, P=0.07).Metabolic risk factors were increasingly prevalent among Asian Americans with HCC. MSEAs, who had the highest incidence of these risk factors, had more advanced tumor stage and trended toward worse survival.

  View details for DOI 10.1097/MCG.0000000000000689

  View details for PubMedID 27636408

• Effects of Cirrhosis on Short-term and Long-term Survival of Patients With Hepatitis B-related Hepatocellular Carcinoma CLINICAL GASTROENTEROLOGY AND HEPATOLOGY Chen, V. L., Le, A. K., Kim, N. G., Kim, L. H., Nguyen, N. H., Nguyen, P. P., Zhao, C., Nguyen, M. H. 2016; 14 (6): 887-?

  Abstract

  Hepatitis B virus (HBV) is the most common cause of hepatocellular carcinoma (HCC) worldwide. Unlike other liver diseases, HBV can cause HCC in the absence of cirrhosis. We investigated whether features of HCC in patients with HBV infection without cirrhosis and survival times differ from those of patients who develop HCC after cirrhosis.We performed a retrospective cohort study of 487 consecutive cases of HBV-related HCC who were seen from 2000 through 2014 at a tertiary care center. Laboratory values, imaging results, and treatment information were obtained from subjects' medical records. Symptoms of HCC included weight loss, abdominal pain, or new hepatic decompensation. The primary outcome was overall survival, which was categorized as short-term survival (up to 3 years after the diagnosis of HCC) or long-term survival (3-10 years after diagnosis).The mean tumor size at diagnosis was significantly larger in patients without cirrhosis (6.4 ± 4.3 cm) than in patients with cirrhosis (5.0 ± 3.8 cm) (P = .0009). A significantly larger proportion of patients without cirrhosis had symptoms at diagnosis (43.8% vs 35.4% in patients without cirrhosis, P = .09). A significantly higher proportion of patients without cirrhosis survived for the long-term (P = .003), but there was no significant difference between groups in short-term survival (P = .37). Notably, the same proportions of asymptomatic patients with and without cirrhosis survived for the short-term (64.3% vs 64.2%, P = .73), but a lower proportion of asymptomatic patients with cirrhosis survived for the long-term (P = .015). In multivariate Cox regression analysis, cirrhosis was an independent predictor of death in 3-10 years (hazard ratio, 3.76; P = .003) but not in less than 3 years (P = .48). Symptoms at diagnosis predicted death within 3 years (hazard ratio, 1.76; P =.006) but not in 3-10 years (P = .15).Patients with HBV infection and HCC without cirrhosis present with larger tumors, and a larger percentage have symptoms of cancer than patients with cirrhosis. This may indicate that HCC surveillance is less than optimal for patients with HBV infection without cirrhosis. Despite this suboptimal surveillance, patients without cirrhosis have higher long-term survival than those with cirrhosis, especially when asymptomatic at diagnosis.

  View details for DOI 10.1016/j.cgh.2015.12.044

  View details for Web of Science ID 000376456400023

  View details for PubMedID 26820401

• Sex differences in disease presentation, treatment and clinical outcomes of patients with hepatocellular carcinoma: a single-centre cohort study. BMJ open gastroenterology Ladenheim, M. R., Kim, N. G., Nguyen, P., Le, A., Stefanick, M. L., Garcia, G., Nguyen, M. H. 2016; 3 (1)

  Abstract

  Although sex differences in hepatocellular carcinoma (HCC) risk are well known, it is unclear whether sex differences also exist in clinical presentation and survival outcomes once HCC develops.We performed a retrospective cohort study of 1886 HCC patients seen in a US medical centre in 1998-2015. Data were obtained by chart review with survival data also by National Death Index search.The cohort consisted of 1449 male and 437 female patients. At diagnosis, men were significantly younger than women (59.9±10.7 vs 64.0±11.6, p<0.0001). Men had significantly higher rates of tobacco (57.7% vs 31.0%, p<0.001) and alcohol use (63.2% vs 35.1%, p<0.001). Women were more likely to be diagnosed by routine screening versus symptomatically or incidentally (65.5% vs 58.2%, p=0.03) and less likely to present with tumours >5 cm (30.2% vs 39.8%, p=0.001). Surgical and non-surgical treatment utilisation was similar for both sexes. Men and women had no significant difference in median survival from the time of diagnosis (median 30.7 (range=24.5-41.3) vs 33.1 (range=27.4-37.3) months, p=0.84). On multivariate analysis, significant predictors for improved survival included younger age, surgical or non-surgical treatment (vs supportive care), diagnosis by screening, tumour within Milan criteria and lower Model for End-Stage Liver Disease score, but not female sex (adjusted HR=1.01, CI 0.82 to 1.24, p=0.94).Although men have much higher risk for HCC development, there were no significant sex differences in disease presentation or survival except for older age and lower tumour burden at diagnosis in women. Female sex was not an independent predictor for survival.

  View details for DOI 10.1136/bmjgast-2016-000107

  View details for PubMedID 27493763

  View details for PubMedCentralID PMC4964155

• Differences in Presentation and Long-Term Survival of Patients with Hepatocellular Carcinoma (HCC) with Hepatitis B Virus (HBV) Compared to Hepatitis C Virus (HCV) or Non-Viral Etiology Chen, V. L., Kim, N. G., Le, A. K., Ladenheim, M. R., Nguyen, P., Zhao, C., Nguyen, M. H. WILEY-BLACKWELL. 2015: 406A

  View details for Web of Science ID 000368375401271

• A Single Center Experience with Hepatocellular Carcinoma (HCC): Shifts in Patient Ethnicity and HCC Etiology but No Improvement in Survival over Time Chen, V. L., Kim, N. G., Le, A. K., Ladenheim, M. R., Nguyen, P., Zhao, C., Nguyen, M. H. WILEY-BLACKWELL. 2015: 425A

  View details for Web of Science ID 000368375401311

• Enhanced Antitumor Efficacy of Low-Dose Etoposide with Oncolytic Herpes Simplex Virus in Human Glioblastoma Stem Cell Xenografts CLINICAL CANCER RESEARCH Cheema, T. A., Kanai, R., Kim, G. W., Wakimoto, H., Passer, B., Rabkin, S. D., Martuza, R. L. 2011; 17 (23): 7383-7393

  Abstract

  Glioblastoma (GBM) inevitably recurs despite surgery, radiation, and chemotherapy. A subpopulation of tumor cells, GBM stem cells (GSC), has been implicated in this recurrence. The chemotherapeutic agent etoposide is generally reserved for treating recurrent tumors; however, its effectiveness is limited due to acute and cumulative toxicities to normal tissues. We investigate a novel combinatorial approach of low-dose etoposide with an oncolytic HSV to enhance antitumor activity and limit drug toxicity.In vitro, human GBM cell lines and GSCs were treated with etoposide alone, oncolytic herpes simplex virus (oHSV) G47Δ alone, or the combination. Cytotoxic interactions were analyzed using the Chou-Talalay method, and changes in caspase-dependent apoptosis and cell cycle were determined. In vivo, the most etoposide-resistant human GSC, BT74, was implanted intracranially and treated with either treatment alone or the combination. Analysis included effects on survival, therapy-associated adverse events, and histologic detection of apoptosis.GSCs varied in their sensitivity to etoposide by over 50-fold in vitro, whereas their sensitivity to G47Δ was similar. Combining G47Δ with low-dose etoposide was moderately synergistic in GSCs and GBM cell lines. This combination did not enhance virus replication, but significantly increased apoptosis. In vivo, the combination of a single cycle of low-dose etoposide with G47Δ significantly extended survival of mice-bearing etoposide-insensitive intracranial human GSC-derived tumors.The combination of low-dose etoposide with G47Δ increases survival of mice-bearing intracranial human GSC-derived tumors without adverse side effects. These results establish this as a promising combination strategy to treat resistant and recurrent GBM.

  View details for DOI 10.1158/1078-0432.CCR-11-1762

  View details for Web of Science ID 000298133600020

  View details for PubMedID 21976549

  View details for PubMedCentralID PMC3229640