The Prognosis of Mucinous Gastric Carcinoma

Lim, Sang Woo; Ryu, Seong Yeob; Kim, Hyeong Rok; Kim, Dong Yi; Kim, Young Jin

Abstract

PURPOSE: Mucinous gastric carcinoma (MGC) is a histopathologic subtype of gastric adenocarcinoma with a poor prognosis. It comprises about 3~10% of gastric carcinomas. The purpose of this study was to compare the disease course of MGC with non-MGC (NMGC) and study the clinicopathologic features that influence the prognosis of MGC patients.
METHODS
We reviewed the records of 2,383 patients with a confirmed histologic diagnosis of gastric carcinoma who underwent surgery at the Department of Surgery, Chonnam National University Hospital. There were 157 patients with MGC compared to 2,226 with NMGC. Patients were evaluated on the basis of gender, age, tumor size, tumor location, depth of invasion, region and number of lymph nodes with metastasis, hepatic or peritoneal metastasis, stage at presentation, estimate of surgical curability, and TNM stage based on the UICC classification. Multivariate analysis was performed to test the hypothesis that the histologic mucin contents themselves in MGC are an independent prognostic factor.
RESULTS
There was no gender or age-at-diagnosis distinction between these two groups. The mean tumor size of MGC was larger than that of NMGC, but the difference was not statistically significant. Most carcinomas of both types were located in the antrum with no statistical difference in location between MGC and NMGC. However, a depth of invasion greater than T3 was more frequently found in MGC than in NMGC, not to a statistically significant degree. The mean number of lymph node with metastases was 2.78 in MGC and 2.28 in NMGC (P<0.001). There were more MGC patients with TNM stages II through IV(UICC classification). The overall survival rate was lower for the MGC group(46.5%) than for the NMGC group (64.0%). Depth of invasion, lymph node metastasis, and stage at diagnosis were significant factors affecting the outcome. Mucinous histologic type itself was not an independent predictive factor in survival.
CONCLUSION
The factors that influence the poorer prognosis(lower 5-year survival rate) of MGC are advanced stage at the time of diagnosis, lymph node metastases, and a higher TNM status. The histologic subtype itself was not an independent prognostic factor.