A multicenter study on adjuvant chemotherapy of S-1 versus observation for resected perihilar cholangiocarcinoma.

person Isamu Hosokawa Department of General Surgery, Chiba University Graduate School of Medicine, Chiba, Japan info_outline Isamu Hosokawa, Ryota Higuchi, Yuki Homma, Tsukasa Takayashiki, Yusuke Ome, Ryusei Matsuyama, Shigetsugu Takano, Shuichiro Uemura, Yasuhiro Yabushita, Daisuke Suzuki, Kentaro Miyake, Goro Honda, Itaru Endo, Masayuki Ohtsuka

Authors person Isamu Hosokawa Department of General Surgery, Chiba University Graduate School of Medicine, Chiba, Japan info_outline Isamu Hosokawa, Ryota Higuchi, Yuki Homma, Tsukasa Takayashiki, Yusuke Ome, Ryusei Matsuyama, Shigetsugu Takano, Shuichiro Uemura, Yasuhiro Yabushita, Daisuke Suzuki, Kentaro Miyake, Goro Honda, Itaru Endo, Masayuki Ohtsuka Organizations Department of General Surgery, Chiba University Graduate School of Medicine, Chiba, Japan, Department of Surgery, Institute of Gastroenterology, Tokyo Women’s Medical University, Tokyo, Japan, Tokyo, Japan, Department of Gastroenterological Surgery, Yokohama City University Graduate School of Medicine, Kanagawa, Japan, Department of Surgery, Institute of Gastroenterology, Tokyo Women’s Medical University, Tokyo, Japan, Department of Gastroenterological Surgery, Yokohama City University, Kanagawa, Japan, Tokyo Women's Medical University, Tokyo, Japan, Department of General Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan Abstract Disclosures Research Funding No funding received None. Background: The prognosis of perihilar cholangiocarcinoma (PHC) is poor even after curative resection. The efficacy of adjuvant S-1 chemotherapy for resected PHC is unclear. This study aimed to assess the efficacy of adjuvant S-1 chemotherapy after major hepatectomy for PHC. Methods: Consecutive patients with PHC who underwent major hepatectomy (hemihepatectomy or trisectionectomy extending to segment 1 with extrahepatic bile duct resection) at three high-volume centers in Japan from 2007 to 2020 were retrospectively evaluated. Patients with Clavien-Dindo grade V complications, pStage I or IVB disease, and those who underwent adjuvant radiation therapy were excluded from analysis. Propensity score matching analysis was performed to compare the disease-specific survival (DSS) of patients who underwent adjuvant S-1 chemotherapy with those who underwent observation. Results: Of 480 patients, 373 were eligible for the study, 81 of whom underwent adjuvant S-1 chemotherapy, and 146 underwent observation. In the global cohort, DSS in the S-1 and observation groups were similar ( P = 0.18). In the matched cohort as well (S-1: n=44, Observation: n=44), DSS was similar between the S-1 and observation groups ( P = 0.09). On multivariate analysis, performance of percutaneous biliary drainage, CA19-9 levels at operation ≥ 300 U/ml, and lymph node (LN) metastasis were independent predictors of poor survival following major hepatectomy for PHC. In subgroup analysis of patients with LN metastasis, DSS in the S-1 group was better than in the observation group ( P = 0.001). Conclusions: Adjuvant S-1 chemotherapy after major hepatectomy might be effective in PHC patients with LN metastasis.