Neuzillet C, et al. - In this retrospective analysis utilizing a development cohort (28 French centers) and three validation cohorts from Italy, UK, and France, authors assessed 405 cases treated with standard first-line (L1) gemcitabine plus oxaliplatin (GEMOX) (91%) or gemcitabine plus cisplatin (GEMCIS) to study the prognostic factors for overall survival (OS) with second-line chemotherapy (L2) in advanced biliary tract cancer (aBTC). Four independent prognostic factors were performance status, the reason for L1 discontinuation, previous resection of primary tumor, and peritoneal carcinomatosis.