Randomized clinical trial of D2 and extended paraaortic lymphadenectomy in patients with gastric cancer.

Background: The survival of patients with advanced gastric cancer after D2 dissection is still poor. Asian surgeons have proposed a more radical lymph node dissection, designated as D4 dissection, where paraaortic lymph nodes are removed in combination with D2 dissection. To evaluate the survival benefit of D4 dissection, a multi-institutional randomized trial of D2 vs D4 gastrectomy was conducted.