Impact of the latest TNM classification for gastric cancer: retrospective analysis on 94 D2 gastrectomies.

The aim of this study was to determine whether the latest edition of tumor-node-metastasis (TNM) classification provides reliable prognostic information. The fifth edition of TNM Classification of Malignant Tumors has introduced for gastric cancer the numeric count of involved lymph nodes whereas their topographic location was considered in earlier editions. For our study, data from 94 patients who underwent D2-gastrectomy were reviewed. The N-factor was scored according to both the Japanese Research Society for Gastric Cancer (JRSGC) classification (n) and, retrospectively, the latest TNM classification (N). Actuarial survival was calculated for both groups. The two staging systems showed similar stratification of actuarial survival with relation to N-stage; in the JRSGC classification no statistical differences were observed between n1 and n2 patients (62.7% vs. 52.5%; p = NS), whereas the 5th TNM classification showed a significant difference between N1 and N2 patients (68.5% vs. 45.0%; p = 0.04), and between N1 and the new category of N3 patients (68.5% vs. 45.0%, p = 0.03). It appears, therefore, that the numeric count of involved nodes may represent a more reliable indicator for single-case prognosis. Reclassification of all node-positive patients in our series caused an overall stage modification in 32.9% (31/94); 22 of those patients were reclassified to a less favorable stage (23.4%). In addition, 11.7% of patients (6/51) who were previously designated n1 were reclassified as N2, shifting from an expected actuarial survival after 72 months of 62.7% to 33.3%.