Extent of lymph node dissection in patients with gallbladder cancer

Background: Definitions of regional lymph nodes for gallbladder cancer differ according to staging system. Hence, the appropriate extent of lymph node dissection has not yet been standardized. Methods: Pathological stages and disease-specific survival (DSS) of patients who had undergone surgical resection of gallbladder cancer between 1990 and 2016 were reviewed. Patients with nodal metastases limited to the hepatoduodenal ligament or common hepatic artery, extending to the posterosuperior pancreatic head lymph nodes (PSPLNs), or in nodes along the coeliac axis or superior mesenteric vessels were grouped as having Na, Nb and Nc disease respectively. Metastases beyond these regions were defined as distant metastases (M1). Absence of distant metastasis was expressed as M0. Results: A total of 259 patients were evaluated. There were 74, 31 and nine patients respectively in the Na, Nb and Nc groups. Twenty-five, nine and four patients in the respective groups had M1 disease (P =0.682). The 5-year DSS rate was comparable between patients with Na M0 and those with NbM0 disease (36 versus 34 per cent respectively; P = B950), whereas the rate in patients with NcM0 status (0 per cent) was worse than that of patients with NbM0 (P=0.017) and comparable to that of patients with MI disease (14 per cent; P = 0.590). Among 22 patients with NbM0 disease, the 5-year DSS rate did not differ between those who had undergone pancreatoduodenectomy and those who had had dissection of PSPLNs without pancreatoduodenectomy (50 versus 30 per cent respectively; P= 0.499). Conclusion: PSPL,Ns and nodes along the hepatoduodenal ligament and hepatic artery should be considered regional nodes for gallbladder cancer, and should be resected.