Prognostic impact of tumor location in resected gallbladder cancer: A national cohort analysis

Background and Objectives: Tumor location (peritoneal vs hepatic) has been incorporated in the 8th edition of the American Joint Committee on Cancer Staging system for gallbladder cancer. However, larger studies are needed to confirm the prognostic impact of tumor location. Methods: Patients with pathologically-confirmed gallbladder cancer with information on primary tumor location were included from the National Cancer Database (2009-2012). We compared patients with hepatic-side tumors to those on the peritoneal side. Survival data were plotted using the Kaplan-Meier method. Prognostic factors were modeled with a multivariate Cox Proportional Hazards Model. Primary outcome was overall survival (OS). Results: A total of 1251 patients were included. In comparison to patients with peritoneal-sided tumors, patients with hepatic-sided tumors were more likely to: be of higher pT stage (pT3: 49% vs 24%; P <.001); node positive (31% vs 24%; P =.016); undergo liver resection (53% vs 25%; P <.001); or have positive margins (29% vs 16%; P <.001). However, on multivariate analysis, there was no difference in OS between the groups (HR, 0.97; 95% CI, 0.79-1.18; P =.753). Liver resection was associated with improved survival regardless of tumor location in pT2 tumors (peritoneal: HR, 0.57; P =.034; hepatic: HR, 0.67; P <.001). Conclusions: This study failed to demonstrate the independent prognostic value of primary tumor location in patients with gallbladder cancer.