Varying lymphadenectomies for gastric adenocarcinoma in the East compared with the west: effect on outcomes.

There are notable differences in surgical approaches to gastric adenocarcinoma throughout the world, particularly in terms of the extent of lymphadenectomy (LAD). In high-incidence countries such as Japan and South Korea, more extensive (e.g., D2) lymphadenectomies are standard, and these surgeries are generally done by experienced surgeons with low morbidity and mortality. In countries such as the United States, where the incidence of gastric adenocarcinoma is 10-fold lower, the majority of patients are treated at nonreferral centers with less extensive (e.g., D1 or D0) lymphadenectomy. There is little disagreement among gastric cancer (GC) experts that the minimum lymphadenectomy that should be performed for gastric adenocarcinoma should be at least a D1 lymphadenectomy, and many of these experts recommend a D2 lymphadenectomy. More extensive lymphadenectomies provide better staging of patient disease and likely reduce locoregional recurrence rates. Two large, prospective randomized trials performed in the United Kingdom and the Netherlands in the 1990s failed to demonstrate a survival benefit of D2 over D1 lymphadenectomy, but these trials have been criticized for inadequate surgical training and high surgical morbidity and mortality rates (10% to 13%) in the D2 group. More recent studies have demonstrated that Western surgeons can be trained to perform D2 lymphadenectomies on Western patients with low morbidity and mortality. The 15-year follow-up of the Netherlands trial now demonstrates an improved disease-specific survival and locoregional recurrence in the D2 group. Retrospective analyses and one prospective, randomized trial suggest that there may be a survival benefit to more extensive lymphadenectomies when performed safely, but this assertion requires further validation.