Tumor Burden Score Stratifies Prognosis of Patients With Intrahepatic Cholangiocarcinoma After Hepatic Resection: A Retrospective, Multi-Institutional Study

Abstract

BackgroundThe prognostic significance of tumor burden score (TBS) on patients who underwent curative-intent resection of intrahepatic cholangiocarcinoma (ICC) has not been evaluated. The present study aimed to investigate the impact of TBS and its synergistic effect with CA19-9 (combination of TBS and CA19-9, CTC grade) on long-term outcomes.MethodsPatients who underwent radical resection of ICC between 2009 and 2017 were retrospectively identified from a multi-center database. The overall survival (OS) and recurrence-free survival (RFS) were examined in relation to TBS, serum preoperative CA19-9, and CTC grade.ResultsA total of 650 patients were included in our study (509 in the derivation cohort and 141 in the validation cohort). Kaplan–Meier curves showed that both TBS and CA19-9 levels were strong predictors of survival outcomes. Patients with elevated TBS grade or elevated CA19-9 were associated with worse OS and RFS (both p < 0.001). As expected, CTC grade also performed well in predicting long-term outcomes. Patients with low TBS/low CA19-9 (CTC grade 1) were associated with the best OS as well as RFS, while high TBS/high CA19-9 (CTC grade 3) correlated to the worst outcomes. In the validation cohort, TBS grade, preoperative CA19-9, and CTC grade also stratified prognosis among patients (p < 0.001 for each).ConclusionsBoth tumor morphology (tumor burden) and tumor-specific biomarker (serum CA19-9) were important when evaluating prognosis of patients with resectable ICC. Serum CA19-9 and TBS showed a synergistic effect on prognostic evaluation. CTC grade was a promising tool in stratifying prognosis of ICC patients after curative resection.