Background: Retrospective studies using multivariate analysis of clinical and pathological features in gastric cancer have identified a number of high-risk, independent prognostic factors. In these clinical features, tumor size can be measured easily before or during the operation without the requirement of any special equipment, but its prognostic value in patients with gastric cancer is unclear. The aim of this study was to review the experience at our institution of gastric adenocarcinoma to determine the influence of tumor size on outcome.
Patients and methods: Between January 1985 and December 1995, 697 patients with gastric adenocarcinoma underwent resection of the stomach at the Department of Surgery, Sendai National Hospital, Japan. Data on age, gender, tumor location, structure and size, evidence of local invasion, and type of operation performed for each patient were obtained. The sizes of tumors were derived from measurements made in fresh resected specimens. The patients were divided into three groups: 102 patients with tumors of less than 2 cm in diameter, 392 patients with tumors of 2-7 cm in diameter, and 203 patients with tumors of more than 7 cm in diameter.
Results: In these three groups, there were statistical differences in tumor location, macroscopic type, depth of invasion, lymph node metastasis, histological type, lymphatic invasion, vascular invasion and cancer-stromal relationship. Patients with larger tumors had more invasion into the gastric wall in terms of depth of invasion and more frequent lymph node metastasis than did patients with smaller tumors. Histologically, diffuse, scirrhous-type was more common in the larger tumor group. The frequency of lymphatic and vascular permeation in the larger tumor group was higher than that in the other groups. The 5-year survival rates according to tumor size were 94.3% in cases of tumors of less than 2 cm, 75.1% in cases of tumors of 2-7 cm, and 26.3% in cases of tumors of more than 7 cm. Multivariate analysis revealed that the prognosis of gastric cancer patients was affected most by depth of invasion, followed by lymph node metastasis and tumor location. Tumor size is not an independent prognostic factor.
Conclusion: In conclusion, according to the results of univariate analysis, tumor size is clinically a predictor of survival of patients with gastric cancer. In multivariate analysis, however, it is not an independent factor, and the presence of lymph node metastasis, depth of invasion and tumor location are more important than tumor size.