Outcome of patients with proximal gastric cancer depends on extent of resection and number of resected lymph nodes

Background: Studies have shown that the survival of patients with gastric adenocarcinoma is related to the number of regional lymph nodes with metastases. The probability of identifying node-positive cancers increases with the number of lymph nodes resected and examined. It has been recommended that at least 15 lymph nodes be removed and examined for adequate staging. Prospective randomized studies have shown the lymph node yield is much greater with the D2 resection than the D1. This study evaluated the relative contribution of both the number of resected lymph nodes and the extent of gastric resection (D1/D2) on the outcome of patients with proximal gastric cancer. Methods: The medical records of 114 patients with adenocarcinoma of the proximal stomach, who underwent a curative gastric resection, were reviewed. Patients were stratified into four groups, i.e., two groups, D1/D1.5 and D2/D2.5, based on the extent of resection, and two groups based on the number of lymph nodes removed, fewer than 15 lymph nodes and 15 or more lymph nodes. Survival was determined by the method of Kaplan-Meier and differences compared by the log-rank test. Multivariate analysis was performed by using the Cox model. Results: The number of resected lymph nodes had no effect on the survival of the group as a whole. A significant improvement in survival was noted for patients with a D2 or greater resection. The median survival of patients with 15 or more lymph nodes resected improved from 25 months to 42 months when treated with an extended resection, (D2 or D2.5). Resection of 15 or more lymph nodes alone, or combined with an extended resection, resulted in a statistically significant improvement in survival for patients in American Joint Committee on Cancer Staging (AJCC) stage II. Conclusions: Both resection of 15 or more lymph nodes and extended lymphadenectomy contributed to the survival advantage observed in patients with AJCC stage II gastric cancer. The D2 gastric resection prolonged the median survival time and improved the 5-year survival rate for patients with 15 or more resected lymph nodes.