Improving the AJCC/TNM classification for use in early gastric cancer.

PURPOSE

The current TNM classification is still unsatisfactory for collecting all the prognostic information from the clinical presentation of early gastric cancer: "T" is limited to two levels, the classes of "N" are still wide and "M" is generally absent.

PATIENTS AND METHODS

This study involved 99 patients who underwent radical gastric resection for early gastric cancer. Clinical and histological parameters were prognostically analyzed for both observed and relative survival. Univariate and multivariate analyses were applied to the proportional hazards model.

RESULTS

Number of metastatic lymph nodes and measure of the largest diameter of the tumor were the only independent prognosticators of observed and relative survival. Their similar relative hazards allowed an additive use of them in the N class. Two cut-off values of this composite clinical parameter are proposed for a good discrimination of the relative survival.

DISCUSSION

The number of metastatic lymph nodes is the cornerstone of the current TNM system and was confirmed as adequate. The possibility of adding tumor size to the number of the involved lymph nodes improves and amplifies the prognostic ability, which is presently limited by the rarity of lymph node involvement and the small number of the lymph nodes usually involved.