Clinicopathologic characteristics and surgical outcomes of mucinous gastric carcinoma.

Background: The clinicopathologic characteristics of mucinous gastric carcinoma (MGC), an uncommon subtype of gastric carcinoma, were examined by comparing 45 MGC and 1255 non-MGC (NGC) cases.

Methods: Of 1300 gastric cancer patients, 1184 (early, n=568; advanced, n=616) underwent potentially curative or palliative resection. Age, sex, tumor location, tumor diameter, macroscopic appearance, depth of invasion, lymph node metastasis, lymphatic invasion, and venous invasion were monitored.

Results: In all registered patients, MGC patients' characteristics were as follows: advanced-stage disease (P=.0293), macroscopically ill-defined tumors (P=.0051), deeper invasion (P=.0046), and more lymph node involvement (P=.0008). Although there were no significant differences between curatively resected MGC and NGC advanced-cancer patients, in curatively resected early-cancer patients, depth of invasion (P=.0060) and lymphatic invasion (P=.0374) were significantly different. Survival time in all registered patients was shorter for MGC patients (P=.0489). Survival of curatively resected advanced and early gastric cancer patients was not significantly different. Age, macroscopic appearance, tumor diameter, depth of invasion, lymph node metastasis, and curability, but not histological type, were independent prognostic factors in all registered patients. Histological type also did not influence prognosis after curative resection. MGC patients had significantly more metastatic lymph nodes and lymphatic and venous invasion. Survival was significantly different (P=.0450) between all patients with undifferentiated and differentiated MGC, but not in curatively resected patients.

Conclusions: MGC patients' poor prognosis correlates with advanced disease at diagnosis. Therapeutic and follow-up plans after curative resected MGC and NGC should remain the same, possibly with alterations according to the former's histological subtype.