Adjuvant chemoradiotherapy in resected gallbladder cancer: A SEER-based study

Background: The prognosis of gallbladder cancer (GBC) is dismal. This study aimed to compare the outcomes of adjuvant chemoradiotherapy (ACR) with those of surgery alone (S) and adjuvant chemotherapy (AC).Method: The Surveillance, Epidemiology, and End Results (SEER) Program database was used to identify patients diagnosed with GBC and undergoing surgery between 2004 and 2015. The pa-tients were divided into the S, AC, and ACR groups according to their treatment. Categorical variables were compared by Pearson's chi-square test, and a 1:1:1 propensity score matching analysis (PSM) was performed. Overall survival was assessed by Kaplan-Meier curves with log -rank tests. Subgroup analyses were conducted.Result: A total of 5451 patients were identified in the SEER database. After PSM, the two-year survival among patients who received S, AC, and ACR was 36%, 39%, and 45%, respectively. ACR was associated with improved two-year survival (p < 0.001), while the survival rates were similar in the AC and S groups (p = 0.127) but better in the ACR group than in the AC group (p = 0.012). Subgroup analyses indicated that while the two-year survival rates did not differ signif-icantly in stage II GBC patients between the groups (all p > 0.05), ACR was associated with significantly improved two-year survival in stage IIIa (p = 0.008), IIIb (p < 0.001), and IVb (p < 0.001) GBC patients. Conclusion: The combination of surgery and ACR as the treatment modality provided greater survival benefits for GBC patients, particularly for those with advanced tumor staging.