Mucinous Adenocarcinoma of the Colon and Rectum

ABSTRACT

PURPOSE: This study was to evaluate and compare the clinical characteristics of a mucinous adenocarcinoma with those of a non-mucinous adenocarcinoma in colorectal cancer patients. METHODS: Data were retrospectively reviewed on 3,232 colorectal cancer patients, including 221 mucinous adenocarcinoma patients (6.1%), who received surgery between 1990 and 2003. RESULTS: The mean tumor size (6.5 cm) of the mucinous adenocarcinomas was bigger than that (5.2 cm) of the non-mucinous adenocarcinomas. The locations of the mucinous adenocarcinomas were 95 (48.2%) in the proximal colon, 35 (17.8%) in the distal colon, and 67 (34.0%) in the rectum whereas those of the non-mucinous adenocarcinomas were 559 (18.9%) in the proximal colon, 861 (29.2%) in the distal colon, and 1,533 (51.9%) in the rectum. Stage distribution was as follows In mucinous adenocarcinomas, 7 stage A (3.3%), 84 stage B (39.3%), 76 stage C (35.5%), and 47 stage D (21.9%). In non-mucinous adenocarcinomas, 447 stage A (15.2%), 1,036 stage B (35.1%), 997 stage C (33.8%), and 469 stage D (15.9%). In the univariate analysis, the overall 5-year survival rate of patients with a mucinous adenocarcinoma was lower than that of patients with a non-mucinous adenocarcinoma (60% vs. 65%, P=0.016), but survival rates for each stage were not significantly different. The difference in recurrence rates was not statistically significant (33.3% vs. 24.2%, P=0.258). A multivariate analysis showed that the mucinous histologic type was not useful as an independent prognostic factor. CONCLUSIONS: Mucinous colorectal adenocarcinomas tend to be large, exist in a proximal location, have an advanced stage at diagnosis. The difference in survival rates for each stage was not statistically significant. A mucinous histologic type was not an independent prognostic factor.