Analysis of the efficacy and factors influencing survival of adjuvant radiotherapy for stage II-III biliary tract carcinoma

BACKGROUND: To determine the efficacy of adjuvant radiotherapy for stage II–III biliary tract carcinoma. METHODS: We retrospectively analyzed the data of 37 patients who underwent radical resection of biliary tract carcinomas at the Affiliated Hospital of Inner Mongolia Medical University between 2016 and 2020. We analyzed survival differences between patients who did (n = 17) and did not (n = 20) receive postoperative adjuvant radiotherapy by using Kaplan–Meier analysis. The log-rank test and Cox univariate analysis were used. The Cox proportional risk regression model was used for the multifactorial analysis of factors influencing prognosis. RESULTS: The median survival time (28.9 vs. 14.5 months) and the 1-year (82.40% vs. 55.0%) and 2-year survival rates (58.8% vs. 25.0%) were significantly higher among patients who received adjuvant radiotherapy than among those who did not (χ(2) = 6.381, p = 0.012). Multifactorial analysis showed that pathological tumor type (p = 0.004), disease stage (p = 0.021), and adjuvant radiotherapy (p = 0.001) were independent prognostic factors in biliary tract carcinoma. Subgroup analyses showed that compared to no radiotherapy, adjuvant radiotherapy significantly improved median survival time in patients with stage III disease (21.6 vs. 12.7 months; p = 0.017), positive margins (28.9 vs. 10.5 months; p = 0.012), and T3 or T4 tumors (26.8 vs. 16.8 months; p = 0.037). CONCLUSION: Adjuvant radiotherapy significantly improved the survival of patients with biliary tract carcinoma, and is recommended especially for patients with stage III disease, positive surgical margins, or ≥ T3.