Background. This study evaluated the prognosis of patients with carcinoma in the gastric remnant stump after distal gastrectomy for benign disease (stump cancer). Methods. Twenty patients with resected stump cancer were studied and compared with 266 patients with resected primary cancer in the upper third of the stomach (primary cancer). Results. The percentages of lymph nodes with metastases located at the lesser curvature and the left gastric artery, respectively, were 50.0% and 25.2% in patients with primary cancer and 15.0% and 5.0% in patients with stump cancer. In patients with remnant gastric cancer, lymph node metastases at jejunal mesentery near anastomotic site were found in 2 of 20 (10.0%). Conclusion. The lymph flow from the remnant stomach seems to be changed by the initial operation, and as a result, in stump cancer, metastatic lymph nodes are located at different places from those associated with primary cancer. Even when curative surgery is performed in patients with stump cancer, it is important to follow up patients and check for possible metastasis to the liver. The 5‐year survival rates were 62.1% and 52.5% for patients with curatively resected primary cancer (n = 203) and stump cancer (n = 17), respectively, and there was no statistical difference between the two groups. There was a distinct difference in terms of patterns of recurrence between patients with curatively resected primary cancer and those with stump cancer. The percentages of peritoneal and hematogenic metastases, respectively, were 40.6% and 31.3% in primary cancer and 0% and 83.3% in stump cancers.

Thirteen samples of gastric tumors that had developed in the remnant stomach (remnant gastric cancer) were compared with 63 samples of primary gastric tumors located in the upper third of the stomach (primary gastric cancer) by both clinicopathologic and flow cytometric analysis. The depths of invasion of all these tumors corresponded to the mucosa, submucosa, or muscularis propria layers and the histological stages were stages I, II, or III. There was no significant difference between the two groups of samples either histopathologi-cally or clinically (the 5-year survival rates were 74.6% for patients with remnant gastric cancer and 90.4% for patients with primary gastric cancer). DNA aneuploidy was encountered in 23.1% of the cases of remnant gastric cancer and in 33.3% of the cases of primary gastric cancer. Little difference was found in the S-phase fractions between tumors and normal gastric mucosa of the upper third of the stomach and the remnant stomach. Thus, while the environments in the upper third of the stomach and in the remnant stomach are very different, histopathological and biological characteristics of adenocarcinomas that developed in the remnant stomach are very similar to those of adenocarcinomas in the upper third of the stomach.