What is an adequate extent of resection for T1 gallbladder cancers?

Objective: The purpose of this study was to analyze clinicopathologic and surgical features and to determine what should be an adequate extent of resection for T1 gallbladder cancers. Summary Background Data: Simple cholecystectomy offers adequate treatment for T1a cancers; however, it remains debatable whether T1b cancers should be treated by simple cholecystectomy or by radical resection. Methods: Two hundred ninety patients with gallbladder cancer underwent surgical resection. A retrospective analysis was conducted on 52 patients with pathologic stage T1 (27 [52%] with T1a and 25 [48%] with T1b). Clinicopathologic features, extents of resection, and survival rates were investigated retrospectively. Results: No lymph node metastasis or lymphovascular or perineural infiltration was observed in those with T1a disease, but 2 of the 25 patients with T1b disease (3.8%) had lymph node metastasis and 1 patient (1.9%) had lymphatic infiltration. Twenty-one of the 52 study subjects (40.3%) underwent simple cholecystectomy. No peritoneal dissemination occurred regardless of the surgical method (laparoscopy or open surgery). Of the 23 radically resected patients (44.2%) in T1b group, 6 patients (11.5%) underwent cholecystectomy and hepatoduodenal lymph node dissection (CholeLN), and 17 patients (32.7%) underwent CholeLN combined with wedge resection of IVb and V segments of liver, common bile duct resection, or pancreaticoduodenectomy. No difference in locoregional recurrence, metastasis, or survival rate was observed regardless of combined resection of an adjacent organ. The overall survival rate for all patients was 96.2%, and for T1a and T1b these were 96.3% and 96%, respectively. Conclusion: When early gallbladder carcinoma is suspected on the basis of imaging findings, further evaluation of the depth of invasion by endoscopic ultrasonography or intraoperative frozen biopsy is advised. Then, if the disease stage is determined to be T1a, laparoscopic or open cholecystectomy alone is curative, and if T1b, cholecystectomy with hepatoduodenal lymph node dissection without combined resection of an adjacent organ is recommended.