A Multicenter Retrospective Study on Adjuvant S-1 Chemotherapy Versus Observation Following Major Hepatectomy for Perihilar Cholangiocarcinoma

The prognosis of perihilar cholangiocarcinoma (PHC) is poor even after curative resection, highlighting the need for effective adjuvant chemotherapy. The efficacy of adjuvant S-1 chemotherapy following major hepatectomy for PHC is unclear, and thus the aim of this study was to elucidate this.

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 0, 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.

Overall, 373/480 patients were eligible, of whom 81 underwent adjuvant S-1 chemotherapy and 146 underwent observation. In the global cohort, DSS was similar in the S-1 and observation groups (p = 0.18), while in the matched cohort (S-1, n = 44; observation, n = 44), DSS was similar between the S-1 and observation groups (p = 0.09). On multivariate analysis, percutaneous biliary drainage (PTBD), CA19-9 levels of ≥ 300 U/mL at operation, 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 was better in the S-1 group than in the observation group (p = 0.001).

Adjuvant S-1 chemotherapy following major hepatectomy might be effective in PHC patients with LN metastasis.