Incidental Carcinoma after Cholecystectomy for Benign Disease of the Gallbladder: A Meta-Analysis.

This study aimed to determine the incidence and the prognosis of incidental carcinoma of the gallbladder (IGBC) after cholecystectomy through a meta-analysis. This meta-analysis included 51 studies and 436,636 patients with cholecystectomy. The incidence rate of IGBC after cholecystectomy was 0.6% (95% confidence interval (CI) 0.5%-0.8%). The incidence rate of recent studies was not significantly different from those of past studies. The mean age and female ratio of the IGBC subgroup were not significantly different from those of the overall patient group. The estimated rates of IGBC were 13.0%, 34.1%, 39.7%, 22.7%, and 12.5% in the pTis, pT1, pT2, pT3, and pT4 stages, respectively. Patients with IGBC had a favorable overall survival rate compared to patients with non-IGBC (hazard ratio (HR) 0.574, 95% CI 0.445-0.739). However, there was no significant difference of disease-free survival between the IGBC and non-IGBC subgroups (HR 0.931, 95% CI 0.618-1.402). IGBC was found in 0.6% of patients with cholecystectomy. The prognosis of patients with IGBC was favorable compared to those with non-IGBC. In the pathologic examination after cholecystectomy for benign diseases, a sufficient examination for histology should be guaranteed to detect IGBC.