Rezaee‐Zavareh, Mohammad Saeid

Background: Hepatocellular carcinoma (HCC) has a poor long-term prognosis due to high recurrence and cirrhosis-related mortality, even after potentially curative treatments such as liver transplantation (LT), surgical resection, or ablation. This study aimed to identify factors associated with ≥10-year survival in HCC patients. Methods: A retrospective cohort study was conducted among HCC patients diagnosed between 2004 and 2022 using the National Cancer Database. Multivariable Cox regression was used to identify predictors of overall survival, and logistic regression was used to identify predictors of ≥10-year survival. Results: Among 249,600 HCC patients, 177,585 (71.2%) died within 5 years, 8613 (3.5%) died at 5–10 years, 54,988 (22.0%) were alive with <10 years of follow-up, and 8219 (3.3%) survived ≥10 years. LT, resection, and ablation were performed in 6.6%, 9.3%, and 11% of patients, respectively. Compared with ablation as the reference group, LT [adjusted odds ratio (aOR) 11.96, 95% confidence interval (CI): 11.27–13.29] and resection (aOR: 2.83, 95% CI: 2.57–3.08) increased the odds of ≥10-year survival, while non-curative treatments reduced the odds compared with ablation (aOR: 0.50, 95% CI: 0.47–0.55). Cox regression results were consistent with the logistic model, confirming the association. Decision tree analysis confirmed LT as the dominant determinant of long-term survival. Black individuals were associated with lower odds of ≥10-year survival (aOR: 0.88, 95% CI: 0.820–0.96) and decreased likelihood of receiving LT (aOR: 0.73, 95% CI: 0.55–0.96). Conclusions: LT offers the best chance of ≥10-year survival in HCC. Ensuring equitable access is essential, especially for Black patients who have lower transplant rates and worse outcomes.

INTRODUCTION: Immune checkpoint inhibitors (ICIs) have become the first-line treatment of unresectable hepatocellular carcinoma (HCC). The prognostic value of immune-related adverse events (irAEs) in these patients remains controversial. We aimed to investigate the association between irAEs and clinical outcomes in patients with HCC treated with ICIs. METHODS: We searched the PubMed, Scopus, Web of Science, and Central Register of Controlled Trials databases for articles published from inception to June 2024, using keywords including ICI, HCC, and irAEs. Statistical analysis was performed with a random effects model. RESULTS: Of 3,028 studies, 24 (4,127 patients) met the criteria for inclusion. Atezolizumab plus bevacizumab was the most common treatment regimen (n = 10 studies). IrAEs were associated with an increased objective response rate (pooled relative ratio: 1.73; 95% confidence interval [CI]: 1.36–2.21, I 2 = 41%), a higher disease control rate (pooled relative ratio: 1.45; 95% CI: 1.21–1.74, I 2 = 74%), and longer progression-free survival (pooled hazard ratio [HR]: 0.66; 95% CI: 0.52–0.84, I 2 = 71%). There was a trend toward longer overall survival for patients with irAEs compared with those without (pooled HR: 0.84; 95% CI: 0.63–1.12, I 2 = 73%). Subgroup analysis indicated a survival benefit for patients with grade 1–2 irAEs (pooled HR: 0.50; 95% CI: 0.36–0.67, I 2 = 0%) and for those with endocrine irAEs (pooled HR: 0.63; 95% CI: 0.48–0.83, I 2 = 12%). DISCUSSION: The development of irAEs is associated with favorable clinical outcomes in HCC, including improved progression-free survival and higher objective response rate. Overall survival benefit was noted in patients with mild irAEs but not those with severe irAEs.

566 Background: Immune checkpoint inhibitors (ICIs) have become the preferred treatment for unresectable hepatocellular carcinoma (HCC). Conflicting data exist regarding the prognostic value of immune-related adverse events (irAEs) in these patients. We aimed to explore potential the association between irAEs and prognosis in HCC patients treated with ICIs. Methods: We searched PubMed, Scopus, Web of Science, and CENTRAL databases for articles published from inception to June 2024 using keywords including ICI, HCC, and irAEs. Two reviewers independently screened studies for eligibility and relevant data. A random effects model was used for statistical analysis, and subgroup analysis was performed by the grade of irAEs. Results: Of 3,028 studies, 25 (n=4,116 patients) met criteria for inclusion. Atezolizumab plus bevacizumab was the most common treatment regimen (n=10 studies). About half (49.5%) of patients experienced irAEs. irAEs were associated with increased objective response rate (ORR) (pooled OR: 1.72; 95% CI: 1.36 – 2.19, I 2 =39%), higher complete response rate (pooled OR: 1.45; 95% CI: 1.21-1.74, I 2 =74%), and longer progression-free survival (PFS) (pooled HR: 0.66; 95% CI: 0.52-0.84, I 2 =71%). Although irAEs were associated with longer overall survival, this difference was not statistically significant (pooled HR: 0.83; 95% CI: 0.62 – 1.11, I 2 =73%). Subgroup analysis showed a survival benefit for patients with grade 1-2 irAEs (pooled HR: 0.50; 95% CI: 0.36-0.67, I 2 =0%) but not for those with grade 3-4 irAEs (pooled HR: 0.95; 95% CI: 0.24-3.72, I 2 =84%). Conclusions: The development of irAEs is associated with a favorable prognosis in HCC, including improved PFS and higher ORR. A survival benefit was noted in patients with mild irAEs, but not in those with severe irAEs. Future studies are needed to determine if a differential survival benefit relates to the continuation vs. discontinuation of ICI therapy.

573 Background: Immunotherapy has shown great efficacy in hepatocellular carcinoma (HCC). No clear consensus exists on when to stop the immune checkpoint inhibitor (ICI) after complete response (CR), and clinical course after stopping ICI remains unknown. Methods: We identified 138 HCC patients who received ICI at Cedars-Sinai Medical Center and Mayo Clinic Rochester from 2016-2023. Modified Response Evaluation Criteria In Solid Tumors (mRECIST) was used to assess treatment response. We further described the clinical course of patients who achieved CR after ICI discontinuation, including cancer recurrence, subsequent treatment, liver transplantation (LT) listing and outcomes. Results: The median age at ICI initiation was 68 years; 79% were male; 55.9% were white; 51.5% were BCLC stage C. 9.4% CRs, 25.4% partial responses, 39.9% stable diseases, and 25.4% progressive disease. Hepatitis C etiology was associated with higher likelihood of CR (P=0.005). Among 13 patients who achieved CR, 10 stopped ICI (60% for LT evaluation, 40% for toxicity). After stopping ICI, 40% had recurrence (Table). 3 patients underwent local therapy for recurrent HCC within Milan criteria and 1 patient restarted ICI for recurrence beyond Milan criteria. Among CR patients, 9 patients underwent LT evaluation after stopping ICI and 7 patients were waitlisted. After listing, 3 dropouts were observed, due to recurrent HCC beyond Milan criteria, sepsis leading to death, and personal preference. 4 patients underwent LT. 2 patients underwent local therapy before LT for recurrent HCC (Table). All transplanted patients had the last dose of ICI more than 1 year before LT (12, 21, 24, and 29 months). On explanted livers, 2 patients had no residual viable tumor and 2 patients had residual HCC within Milan criteria. 1 patient developed acute cellular rejection and was treated with immunosuppressants and maintained stable graft function. None had graft loss or evidence of HCC recurrence in the follow-up period at 8, 20, 28, and 51 months. Conclusions: Immunotherapy demonstrated excellent effects on a subset of HCC patients, including 9.4% who achieved CR. After stopping ICI, 40% had cancer recurrence but 3 out of 4 were within Milan criteria. 4 underwent successful LTs (2.9%) with excellent post LT outcome. Larger prospective data is needed to establish a protocol for ICI use, especially to determine the optimal timing for ICI discontinuation after CR. BCLC at ICI initiation ICI cycles before stopping, ICI Recurrence after last ICI (days) Within Milan at recurrence Treatment(s) received after recurrence and outcomes OS (days) Patient 1 B 7, Nivolumab 730 No Nivolumab. Died from GI bleeding 1065 Patient 2 B 64, Atezo/Bev 149 Yes TACE with CR, followed by LT without recurrence. 1203 Patient 3 A 8, Nivolumab 1393 Yes Y90 with CR. No recurrence. 1984 Patient 4 C NA, Pembrolizumab 407 Yes TACE and MWA with CR, followed by LT without recurrence. 1722