Background and objectives: The relationship between the number of lymph nodes examined and the outcome in patients with node-negative (N(-)) gastric cancer was studied. We compared N(-) patients to those with nodal involvement (N(+)) to identify clinicopathologic characteristics of N(-) gastric cancer. Finally, we evaluated outcome indicators in this group of patients.
Methods: Of 367 patients, 130 (35.4%) were N(-). These patients were stratified according to the main prognostic variables, to assess differences with N(+) cases. A statistical analysis using the Cox model was performed to estimate outcome indicators.
Results: N(-) gastric carcinomas were significantly different from N(+) cases in terms of tumor depth and site, TNM stage, grading, residual disease, and vessel involvement. The overall 5-year survival rate was 72%. It was 82% in those patients with more than 15 nodes retrieved and 59% in the others. Serosal involvement, residual disease, and poor differentiation were independent prognostic factors.
Conclusions: The clinicopathologic factors and outcome of N(-) cases were similar to those of early gastric cancer. At least 15 examined nodes appears to be necessary to define a case as N(-). The prognostic value of D2 lymphadenectomy in N(-) patients suggests a biologic role of micrometastases.
Copyright 2000 Wiley-Liss, Inc.