Incidental gallbladder cancer after routine cholecystectomy: when should we suspect it preoperatively and what are predictors of patient survival?

PURPOSE: In about 1% of cases, incidental gallbladder cancers (iGBC) are found after routine cholecystectomy. The aim of this study is to compare clinical features of iGBC with benign GB disease and to evaluate factors affecting recurrence and survival. METHODS: Between January 1998 and March 2014, 4,629 patients received cholecystectomy and 73 iGBC patients (1.6%) were identified. We compared clinical features of 4,556 benign GB disease patients with 73 iGBC patients, and evaluated operative outcomes and prognostic factors in 56 eligible patients. RESULTS: The iGBC patients were older and concomitant diseases such as hypertension and anemia were more common than benign ones. And an age of more than 65 years was the only risk factor of iGBC. Adverse prognostic factors affecting patients' survival were age over 65, advanced histology, lymph node metastasis, and lymphovascular invasion on multivariate analysis. Age over 65 years, lymph node involvement, and lymphovascular invasion were identified as unfavorable factors affecting survival in subgroup analysis of extended cholecystectomy with bile duct resection (EC with BDR, n = 22). CONCLUSION: Prior to routine cholecystectomy, incidental GB cancer should be suspected especially in elderly patients. And advanced age, lymph node metastasis, and lymphovascular invasion are important prognostic factors in EC with BDR cohorts.