Clinicopathological and prognostic differences between mucinous gastric carcinoma and signet-ring cell carcinoma

Objective: To analyze the differences in clinicopathologic characteristics and prognosis between mucinous gastric carcinoma (MGC) and signet-ring cell carcinoma (SRCC). Methods: Clinicopathologic and prognostic data of 1,637 patients with histologically confirmed MGC or SRCC who received surgical operations in the Department of Gastroenterological Surgery, Beijing Cancer Hospital between December 2004 and December 2009 were retrospectively collected and analyzed. The clinicopathological features were analyzed statistically using χ 2 test. Survival was analyzed using the Kaplan-Meier method and multivariate analysis of Cox proportional hazards regression model (backward, stepwise). Results: A total of 181 patients with gastric cancer (74 MGC, 107 SRCC) were included. MGC, when compared with SRCC, was featured by senile patients, stage III and IV, upper third stomach, large tumor size, positive lymph node metastasis, and positive lymphatic vascular invasion (P<0.05). The overall 5-year survival rate showed no difference between the two groups (48.8% vs. 44.8%, P>0.05). However, the survival rate for MGC patients was significant lower than that for SRCC patients when compared among the age <60 years, negative distant metastasis, and tumor localized at upper third stomach (P<0.05). Multivariate Cox proportional hazards models revealed that distant metastasis was a significant independent prognostic indicator in MGC group, and lymph node metastasis and distant metastasis was significant independent prognostic indicators in SRCC group. Conclusions: While compared with SRCC, MGC is associated with a more aggressive tumor biologic behavior. There is no statistically significant difference in distant metastasis, an independent prognostic indicator for both MGC and SRCC, which might be the reason for no significant difference of the overall survival rate between the patients with MGC and SRCC.