The Efficacy of S-1 as Adjuvant Chemotherapy for Resected Biliary Tract Carcinoma: A Propensity Score-Matching Analysis

Abstract

Even though S-1 is a widely used chemotherapeutic agent, there is no evidence for its use in an adjuvant setting for biliary tract carcinoma (BTC). Patients who underwent surgical treatment for BTC between August 2007 and December 2018 were selected. Propensity score matching was performed between patients who received S-1 as adjuvant chemotherapy (S-1 group) and those who underwent surgical treatment alone (observation group). Of 170 eligible patients, 38 patients were selected in each group after propensity score matching. Among those in the matched cohort, both the median recurrence-free survival (RFS) and overall survival (OS) in the S-1 group were significantly longer than those in the observation group (RFS, 61.2 vs. 13.1 months, p = 0.033; OS, not available vs. 28.2 months, p = 0.003). A multivariate analysis of the OS revealed that perineural invasion and adjuvant S-1 chemotherapy were independent prognostic factors. According to a subgroup analysis of the OS, the S-1 group showed significantly better prognoses than the observation group among patients with perineural invasion (p < 0.001). S-1 adjuvant chemotherapy might improve the prognosis of BTC, especially in patients with perineural invasion.

Clinical efficacy of adjuvant treatments for patients with resected biliary tract cancer: a systematic review and network meta-analysis

“…The main characteristics of the studies included in the network meta-analysis are presented in table 1. These 19 studies consisted of 3 RCTs16 74 75 and 16 retrospective studies 76–91. The patients of 6 studies16 75 79 83 84 91 were Westerners (Americans, French and British) and 13 studies74 76–78 80–82 85–90 were Asian (Japanese, Korean, Indian and Chinese).…”

“…These 19 studies consisted of 3 RCTs16 74 75 and 16 retrospective studies 76–91. The patients of 6 studies16 75 79 83 84 91 were Westerners (Americans, French and British) and 13 studies74 76–78 80–82 85–90 were Asian (Japanese, Korean, Indian and Chinese). Four studies80 87 88 91 assessed patients with GBC, and 11 studies74 76–79 82–86 89 assessed patients with CCA.…”

“…Of the 11 studies, 2 studies85 86 particularly examined the outcomes of iCCA, and 6 studies74 76 77 83 84 89 examined the outcomes of eCCA, including pCCA76 89 and dCCA 83 84. In the remaining four studies,16 75 81 90 the BTC subtypes involved were varied.…”

“…The quality assessment of 16 retrospective studies is listed in online supplemental table 4), which shows that 12 studies76–78 81–85 87 89–91 were judged to be of high quality, and 4 studies79 80 86 88 were judged to be of moderate quality. Of these studies, four were assigned only one star in ‘comparability’ due to the unreported RM79 86 or LN status 80 88.…”

“…Of these studies, four were assigned only one star in ‘comparability’ due to the unreported RM79 86 or LN status 80 88. Ten studies obtained 0 star in item 8 in relation to ‘outcome’ due to the inadequacy of follow-up 77 79–84 86–88 90 Online supplemental figure 1…”