Incidental Gallbladder Cancer on Cholecystectomy: Strategy for Re-resection of Presumed Benign Diseases from a Retrospective Multicenter Study by the Yokohama Clinical Oncology Group

Current expert consensus recommends re-resection for incidental gallbladder cancer (IGBC) of pT1b-3. This study examined whether this consensus was reasonably applicable to patients with IGBC in one Japanese region. This was a multicenter, retrospective analysis of cholecystectomies for presumed benign diseases between January 2000 and December 2009. IGBC was diagnosed in 70 (1.0%) out of 6,775 patients undergoing cholecystectomy. Five-year disease-specific cumulative survival was 100% in 19 patients with pT1a, 80.0% in five with pT1b, 49.5% in 33 with pT2, and 23.1% in 13 with pT3. Re-resection was not performed for the 24 patients with pT1a/1b disease, whereas 24 out of 46 patients with pT2/3 underwent re-resection. Regardless of re-resection, independent factors associated with a poor prognosis on multivariate analysis were grade 2 or poorer disease and bile spillage at prior cholecystectomy. In the 24 patients with pT2/3 re-resection, 11 patients without either of these two factors had significantly better 5-year disease-specific cumulative survival than the 13 patients with one or two independent factors associated with a poor prognosis (72.7% vs. 30.8%, p=0.009). This Japanese regional study suggests that indication of re-resection for IGBC should not be determined by pT-factor alone and that much more attention should be paid to pathological and intraoperative findings at prior cholecystectomy.