“Biological R2” resection for intrahepatic cholangiocarcinoma: identification of patients at risk for poor oncologic outcomes after curative-intent resection

Introduction: We sought to define a cohort of patients with “biological R2” (bR2) resection, defined as recurrence within 12 weeks, following curative-intent resection for intrahepatic cholangiocarcinoma (ICC). In addition, we sought to identify factors associated with bR2 risk. Methods: Patients who underwent upfront curative-intent surgery for ICC were identified from an international, multi-institutional database. The weighted beta-coefficients of preoperative risk factors were used to construct an online tool to predict bR2. Results: Among 1138 patients, 106 (9.3 %) patients had a bR2 resection. Patients with bR2 were more likely to be younger (OR 0.97) and non-White (OR 2.19), as well as more often had cirrhosis (OR 2.11), a higher neutrophil-to-lymphocyte ratio (OR 1.07), a higher tumor burden score (OR 1.16), and metastatic nodal disease on preoperative imaging (OR 1.92). Patients categorized as low-risk had a 3.2 % risk of bR2, intermediate-risk patients had an 11.1 % risk of bR2, whereas patients in the high-risk category had a 27.6 % risk of bR2 (p < 0.001). An online tool was made available at https://junkawashima.shinyapps.io/bR2_ICC/, https://junkawashima.shinyapps.io/CRLMfollwingchemotherapy/. Conclusions: Approximately one in ten patients with resectable ICC had a bR2 resection. An online calculator can may help clinicians identify patients with ICC at highest risk of a bR2 resection.