Factors correlated with number of metastatic lymph nodes in gastric cancer

Objective: We had previously reported a reasonable categorization of the number of positive lymph nodes (LN: 0, 1-4, 5-8, and > 8) as a prognostic indicator. This study was an extension, to see which factors correlated with number of positive lymph nodes. Methods: A total of 533 patients with gastric adenocarcinoma, who underwent curative surgery between January 1988 and December 1995, were entered into this study. Patients were divided into four groups according to metastatic LN number (0, 1-4, 5-8, and > 8). Their survival and clinicopathological factors were analyzed. Results: A total of 16,457 LNs, with an average of 30.9 per specimen, were removed, of which 1686 (10.2%) showed metastases. The 5-yr cumulative survival rate decreased as the number of metastatic LNs increased, i.e., 91.3% for LN 0; 67.4% for LN 1-4; 37.2 for LN 5-8, and 14.1% for LN > 8. Multivariate analyses showed that depth of cancer invasion (odds ratio: 2.4), gross appearance (odds ratio: 1.9), size (odds ratio: 1.9), and location (odds ratio: 1.4) of tumor were four independent factors correlated with the number of metastatic LNs. Number of metastatic LNs increased with advanced Japanese nodal stage and UICC-TNM stage. Conclusions: Depth of tumor invasion, and gross appearance, size, and location of tumor were four pathological factors independently correlated with number of metastatic LNs in gastric cancer.