Clinicopathologic Characteristics of Mucinous Gastric Adenocarcinoma

ABSTRACT

PURPOSE: Clinicopathological characteristics of mucinous gastric adenocarcinomas (MGC) are unclear. Also, whether the surgical results of a MGC are unfavorable is still controversial. A tumor is defined as a MGC when more than 30% of the tumor area has mucin pools. Also, MGC are subdivided into the well-differentiated (WD) and poorly differentiated (PD) types, according to the degree of glandular formation of the tumor cells. To clarify the significance of MGC, the clinicopathological profiles and prognoses of patients were studied. METHODS: Thirty-four patients with MGC and 1, 036 with non-mucinous gastric adenocarcinomas (NMGC) who were operated on between 1992 and 2002 at the Department of Surgery, Hanyang University Hospital, were included. Patients were evaluated with regard to age, gender, tumor location, size, depth of wall invasion, lymph node status, distant metastasis, stage at presentation, lymphatic and vascular permeation, operative curability, and preoperative serum levels of CEA and CA19-9. RESULTS: MGC tumors, compared with NMGC tumors, had larger sizes (8.0 vs. 5.9 cm), more frequent incidences of T2 or more invasion (91 vs. 66%), positive lymph node metastasis (85 vs. 57%), distant metastasis (18 vs. 6%), stage III and IV (74 vs. 45%), noncurative surgery (32 vs. 10%), lymphatic permeation (88 vs. 63%), and abnormal serum CEA level (32 vs. 14%). However, the overall survival rate of those patients with a MGC was not significantly different from that of those with a NMGC. With a MGC, there was no significant correlation between the degree of mucin content and the prognosis. Conversely, the survival rate was higher in the WD than in the PD types (100 vs. 45%, P=0.0185). CONCLUSION: The mucinous histological type itself is of no prognostic significance in patients with gastric carcinomas. The biological behavior of MGC is determined by the degree of glandular formation of the tumor cellss (i.e., histologic differentiation).