Tumor Size Improves the Accuracy of the Prognostic Prediction of Lymph Node-Negative Gastric Cancer

Background: Tumor size has been regarded as the "T" stage of many solid tumors because of its effect on prognosis. However, the prognostic impact of tumor size in gastric cancer (GC) is still controversial.

Materials And Methods: A total of 436 patients with curatively resected GC and those without lymph node metastasis in our center were retrospectively enrolled. The appropriate cutoff points for tumor size were determined. Potential prognostic factors were analyzed. In addition, a pathological tumor-size (pTS) classification system was proposed to evaluate the superiority of its prognostic prediction of node-negative GC patients compared with that of the pT staging system.

Results: The ideal cutoff points for tumor size were 4 and 8 cm. In the multivariate analysis, tumor size was identified as an independent prognostic factor for node-negative GC patients after surgery, as was pT stage. The pTS classification was found to be more appropriate for predicting the overall survival of node-negative GC patients after curative surgery than pT stage, and the -2 log-likelihood of the pTS classification (1680.782) was smaller than the value of pT (1695.239).

Conclusions: As an independent prognostic factor, tumor size should be incorporated into the pT staging system to enhance the accuracy of the prognostic prediction of node-negative GC patients.