Incidental versus non-incidental gallbladder cancer: index cholecystectomy before oncologic re-resection negatively impacts survival in T2b tumors.

BACKGROUND: Conflicting data exists whether non-oncologic index cholecystectomy (IC) leading to discovery of incidental gallbladder cancer (IGBC) negatively impacts survival. This study aimed to determine whether a subgroup of patients derives a disadvantage from IC.

METHODS: Patients with IGBC and non-IGBC treated at an academic USA and Chilean center during 1999-2016 were compared. Patients with T1, T4 tumor or preoperative jaundice were excluded. T2 disease was classified into T2a (peritoneal-side tumor) and T2b (hepatic-side tumor). Disease-specific survival (DSS) and its predictors were analyzed.

RESULTS: Of the 196 patients included, 151 (77%) had IGBC. One hundred thirty-six (90%) patients of whom 118 (87%) had IGBC had T2 disease. Three-year DSS rates were similar between IGBC and non-IGBC for all patients. However, for T2b patients, 3-year survival rate was worse for IGBC (31% vs 85%; p = 0.019). In multivariate analysis of T2 patients, predictors of poor DSS were hepatic-side tumor hazard ratio [HR], 2.9; 95% CI, 1.6-5.4; p = 0.001) and N1 status (HR, 2.4; 95% CI, 1.6-3.6; p < 0.001).

CONCLUSIONS: Patients with T2b gallbladder cancer specifically benefit from a single operation. These patients should be identified preoperatively and referred to hepatobiliary center.