A randomized controlled trial has started in Japan to evaluate the role of splenectomy in the surgical management of gastric cancer. Patients with T2 or deeper carcinoma in the proximal third of the stomach are intra-operatively randomized to either splenectomy or spleen preservation. Tumors invading the greater curvature of the stomach or those with apparent nodal involvement in the splenic hilum are excluded. Surgeons in 29 specialized institutions will recruit 500 patients. Endpoints are overall survival, operative morbidity, operative time and blood loss.