Depth of subserosal invasion predicts long-term survival after resection in patients with T2 gallbladder carcinoma

Background: This study aimed to identify a subgroup of patients with inapparent T2 gallbladder carcinoma who may be best suited for radical second resection. Methods: A retrospective analysis was conducted of 126 patients with pathologic stage T2 (pT2) gallbladder carcinoma (51 with clinically evident tumor and 75 with inapparent tumor). Depth of subserosal invasion was measured histologically in each gallbladder specimen. The median follow-up period was 113 months. Results: In all 126 patients, depth of subserosal invasion was the strongest independent prognostic factor by univariate (P < .0001) and multivariate (relative risk, 9.27; P < .0001) analyses. Among the 75 patients with inapparent tumor, the outcome after resection was significantly better in patients who had undergone radical second resection than in patients who had undergone cholecystectomy alone (P = .0006). When depth of subserosal invasion was divided into less than or equal to2 vs. >2 mm, the effectiveness of radical second resection remained only in patients with subserosal invasion >2 mm (P = .0004). Conclusions: Depth of subserosal invasion best predicts postresectional long-term survival of pT2 gallbladder carcinoma patients. Among patients with inapparent pT2 tumors, those with subserosal invasion >2 mm are good candidates for radical second resection.