Tumor diameter as a prognostic factor in patients with gastric cancer

Background: The aim of this study was to evaluate the prognostic value of tumor diameter in gastric cancer. Methods: The study group comprised a series of 1215 patients who underwent curative gastrectomy. The appropriate tumor diameter cutoff value was determined. Prognostic factors were evaluated by univariate and multivariate analyses. Results: The tumor diameter cutoff value was 100 mm. Multivariate analysis showed that tumor site, macroscopic appearance, tumor diameter, depth of invasion, and presence of lymph node metastasis independently affected prognosis in all patients. Multivariate analysis of patients with larger tumors identified depth of invasion as an independent prognostic factor. A comparison between patients with smaller and larger tumors showed marked differences in the survival of those with stage II, IIIA, and IIIB tumors. A comparison of clinicopathological factors between stage II and III patients revealed that tumors occupying the entire stomach, ill-defined, undifferentiated, and serosa-penetrating tumors, and peritoneal metastases were far more frequent in patients with larger tumors. Conclusions: Tumor diameter in gastric cancer is a reliable prognostic factor that might be a candidate for use in the staging system. To improve outcomes for patients with tumors >= 100 mm in diameter, it is necessary to establish therapeutic strategies for peritoneal metastasis, particularly in stage II and III tumors.