Clinicopathological Analysis and Subclassification of Submucosal Gastric Adenocarcinoma

Kwon, Sung Joon; Kim, Gang Sik

Abstract

BACKGROUND: The aim of this study was to determine the independent prognostic factors in submucosal gastric adenocarcinomas, especially after subclassifying them according to their degree of invasion into the submucosal layer of the stomach.
METHODS
Among the gastric cancer patients who were diagnosed and operated on at the Department of General Surgery, Hanyang University Hospital, during the ten years from 1987 to 1996, 169 cases of submucosal tumors were analyzed. One hundred and twenty-eight cases of mucosal tumors and 132 cases of proper muscle tumors were compared with a control group of submucosal tumors. All the pathologic slides of the submucosal tumor cases were reviewed again and were subclassified into sm1, sm2, and sm3 according to their depth of invasion. Several clinico-pathological factors, including age, sex, lymph node metastasis, histologic differentiation, macroscopic type, depth of invasion, and size of tumor, were evaluated and analyzed.
RESULTS
The ratio of lymph node metastasis increased with the degree of submucosal invasion; however, there was no relation with the size of the tumor. Among various factors, the subclassification of the depth of submucosal invasion was the only factor influencing the ratio of lymph node metastasis; however, these subclassifications did not independently influence the survival rates. The survival rate of patients with larger submucosal tumors was better than that of patients with smaller ones. The univariate and the multivariate survival analyses applied to these factors showed that age, lymph node metastasis, and size of tumor were meaningful prognostic factors.
CONCLUSIONS
For the application of endoscopic mucosal resection for sm1 tumors, we should develop more delicate preoperative diagnostic methods which can accurately subclassify the submucosal tumor into sm1, sm2, or sm3.