Adjuvant systemic treatment in resected biliary tract cancer: State of the art, controversies, and future directions

Biliary tract cancer (BTC) includes a heterogeneous group of aggressive malignancies comprising gallbladder cancer (GBC), ampulla of Vater cancer (AVC), intrahepatic cholangiocarcinoma (iCCA), and extrahepatic cholangiocarcinoma (eCCA). Unfortunately, potentially curative resection is possible in approximately the 25% of presenting patients, and relapse rates are high, with a notable proportion of BTCs experiencing disease recurrence. Recent years have seen the publication of several prospective clinical trials evaluating the role of adjuvant systemic treatments, and among these, the phase III BILCAP study provided evidence supporting the use of capecitabine after radical surgery in BTC patients; in fact, although the study failed to meet its primary endpoint, the capecitabine arm showed improved clinical outcomes in terms of overall survival (pre-planned sensitivity analysis in the intention-to-treat population and in the per-protocol analysis) and relapse-free survival. However, the BILCAP has been widely criticized, with several authors that have not accepted adjuvant capecitabine as novel standard of care. In this review, we summarize current state of the art regarding adjuvant systemic treatment in BTC, highlighting advantages and disadvantages of recent clinical trials, and suggesting new research directions in this setting.