Impact of adjuvant chemotherapy on survival in patients with intrahepatic cholangiocarcinoma: a multi-institutional analysis

Background: The benefit of adjuvant chemotherapy for resected intrahepatic cholangiocarcinoma (ICC) is unclear. The aim of the current study was to investigate the impact of adjuvant chemotherapy on survival among patients undergoing resection of ICC using a multi-institutional database. Methods: 1154 ICC patients undergoing curative-intent hepatectomy between 1990 and 2015 were identified from 14 institutions. Cox proportional hazard modeling was used to determine the impact of adjuvant chemotherapy on overall survival (OS). Results: Following resection, 347 (30%) patients received adjuvant chemotherapy, most commonly a gemcitabine-based regimen (n = 184, 52%). Patients with T2/T3/T4 disease were more likely to receive adjuvant therapy compared with patients with T1a/T1b disease (OR 2.5, 95% CI 1.89-3.23; P < 0.001). Among patients who did and did not receive adjuvant therapy, patients with T2/T3/T4 tumors had a 5-year OS of 37% (95% CI 28.9-44.4) versus 30% (95% CI 23.8-35.6), respectively (p = 0.006). Similarly patients with N1 disease who received adjuvant chemotherapy tended to have improved 5-year OS (18.3%, 95% CI 9.0-30.1 vs. no adjuvant therapy 12%, 95% CI 3.9-24.4; P = 0.050). Conclusions: While adjuvant chemotherapy did not influence the prognosis of all ICC patients following surgical resection, it was associated with a potential survival benefit in subgroups of patients at increased risk for recurrence, such as those with advanced tumors.