Background: Tumor location is a prognostic factor for survival in patients with T2 gallbladder cancer. However, the optimal extent of resection according to tumor location remains unclear.

Methods: We reviewed the records of 192 patients with T2 gallbladder cancer who underwent R0 or R1 resection at 6 institutions. Perioperative and oncologic outcomes were compared according to the extent of resection between hepatic-sided (n = 93) and peritoneal-sided (n = 99) tumors.

Results: After a median follow-up of 30 months, the 5-year overall survival (84.9% vs 71.8%, P = .048) and recurrence-free survival (74.6% vs 62.2%, P = .060) were greater in peritoneal-sided T2 patients than in hepatic-sided T2 patients. Among hepatic-sided T2 patients, the 5-year overall survival was greater in patients who underwent radical cholecystectomy including lymph node dissection with liver resection than in patients who underwent lymph node dissection without liver resection (80.3% vs 30.0%, P = .032), and the extent of liver resection was not associated with overall survival (P = .526). Lymph node dissection without liver resection was an independent prognostic factor for overall survival in hepatic-sided T2 gallbladder cancer (hazard ratio 5.009, 95% confidence interval 1.512-16.596, P = .008). In peritoneal-sided T2 patients, the 5-year overall survival was not significantly different between the lymph node dissection with liver resection and the lymph node dissection without liver resection subgroups (70.5% vs 54.8%, P = .111) and the extent of lymph node dissection was not associated with overall survival (P = .395).

Conclusion: In peritoneal-sided T2 gallbladder cancer, radical cholecystectomy including lymph node dissection without liver resection is a reasonable operative option. Radical cholecystectomy including lymph node dissection with liver resection is suitable for hepatic-sided T2 gallbladder cancer.