Adjuvant concurrent chemoradiation therapy in patients with microscopic residual tumor after curative resection for extrahepatic cholangiocarcinoma.

Purpose: We investigated the role of adjuvant concurrent chemoradiation therapy (CCRT) in patients with a microscopically positive resection margin (R1) after curative resection for extrahepatic cholangiocarcinoma (EHCC).

Methods/patients: A total of 84 patients treated with curative resection for EHCC were included. Fifty-two patients with negative resection margins did not receive any adjuvant treatments (R0 + S group). The remaining 32 patients with microscopically positive resection margins received either adjuvant CCRT (R1 + CCRT group, n = 19) or adjuvant radiation therapy (RT) alone (R1 + RT group, n = 13).

Results: During the median follow-up period of 26 months, the 2-year locoregional recurrence-free survival (LRRFS), disease-free survival (DFS), and overall survival rates (OS) were: 81.8, 62.6, and 61.5% for R0 + S group; 71.8, 57.8, and 57.9% for R1 + CCRT group; and 16.8, 9.6, and 15.4% for R1 + RT group, respectively. Multivariate analysis revealed that the R1 + CCRT group did not show any significant difference in survival rates compared with the R0 + S group. The R1 + RT group had lower LRRFS [hazard ratio (HR) 3.008; p = 0.044], DFS (HR 2.364; p = 0.022), and OS (HR 2.417; p = 0.011) when compared with the R0 + S and R1 + CCRT group.

Conclusions: A lack of significant survival difference between R0 + S group and R1 + CCRT group suggests that adjuvant CCRT ameliorates the negative effect of microscopic positive resection margin. In contrast, adjuvant RT alone is appeared to be inadequate for controlling microscopically residual tumor.