Survival benefit of "D2-plus" gastrectomy in gastric cancer patients with duodenal invasion.

Background: The optimal extent of lymph node (LN) dissection for gastric cancer with duodenal invasion is yet to be clarified. This study sought to evaluate the significance of gastrectomy with D2-plus lymphadenectomy including posterior LNs along the common hepatic artery (no. 8p), hepatoduodenal ligament LNs along the bile duct (no. 12b) and those behind the portal vein (no. 12p), LNs on the posterior surface of the pancreatic head (no. 13), LNs along the superior mesenteric vein (no. 14v) and para-aortic LNs around the left renal vein (nos. 16a2 and 16b1) dissection.

Methods: Patients with gastric cancer with duodenal invasion undergoing R0 gastrectomy from January 2000 to December 2015 were enrolled. The therapeutic value index (TVI) of each LN dissection was calculated by multiplying the incidence of metastasis to each LN station by the 5-year overall survival (OS) rate of the patients with metastasis to the station.

Results: In total, 117 patients were eligible. The 5-year OS rates (and TVI) of the patients with metastasis to LNs were 40.4% (7.4) in no. 12b, 25.4% (6.8) in no. 13, 32.0% (6.1) in no. 14v, 50.0% (13.0) in no. 16a2 and 40.0% (10.0) in no. 16b1. None of the patients with metastasis in no. 8p or no. 12p survived 5 years or longer.

Conclusion: In a potentially curative gastrectomy for gastric cancer with duodenal invasion, there may be some survival benefit in dissection of nos. 12b, 13, 14v, 16a2 and 16b1 LNs, while no benefit was seen in dissection of nos. 8p or 12p LNs.