Clinical benefit of adjuvant chemotherapy in resected T2N0 distal cholangiocarcinoma: a retrospective cohort study.

PURPOSE: Several studies have reported that adjuvant chemotherapy (AC) improves survival outcomes in patients with distal cholangiocarcinoma (dCCA). However, definitive evidence supporting the efficacy of AC in dCCA patients with early T-stage and node-negative disease remains lacking. This study aimed to investigate the clinical benefit of AC and prognostic factors in patients with the early stage of dCCA, with a focus on resected T2N0 dCCA. METHODS: A total of 123 patients who underwent curative surgery with pathological confirmation of T2N0 dCCA between 2000 and 2022 were reviewed using prospectively collected clinicopathologic data. RESULTS: No significant between-group differences were observed in 5-year overall survival (OS) (64.8% vs. 68.5%, P = 0.247) and recurrence-free survival (RFS) (54.6% vs. 59.4%, P = 0.317). Furthermore, no significant differences were observed in locoregional RFS (71.7% vs. 75.5%, P = 0.269) and distant metastasis-free survival (71.7% vs. 76.5%, P = 0.414). Multivariate analysis revealed that the effect of AC was not meaningful and only R1 resection was an independent negative prognostic factor for both OS and RFS. In subgroup analysis, neither AC nor adjuvant radiotherapy was associated with survival outcomes in the R1 resection group. CONCLUSION: Routine use of AC did not significantly improve postoperative survival outcomes in patients with completely resected T2N0 dCCA, nor was its clinical benefit remarkably even in the high-risk group (positive resection margins). Therefore, achieving an R0 resection appears to be more important for improving postoperative survival outcomes in T2N0 dCCA.