Prognostic significance of mucinous carcinoma of colon and rectum: a prospective case-control study.

Abstract

The clinical meaning of mucinous type of colonic and rectal carcinoma is still controversial. We used clinicopathological and follow-up data prospectively recorded for our series of colon and rectum cancer to compare 2 matched groups of mucinous and nonmucinous cancer patients. Two-hundred-forty-eight patients operated for colon and rectum cancer between January 1986 and January 1997 were considered. Thirty-six patients showed mucinous pattern on histologic examination but only 29 (11.7%) had more than 50% of mucin-secreting acini and could be classified as mucinous type. The 29 mucinous cancer patients were compared with 212 nonmucinous cancer patients to evaluate differences in epidemiological and clinical features. A control group from the nonmucinous patients was sorted by matching for age, sex, location, and Dukes stage. In the case-control groups, survival was better for nonmucinous than for mucinous tumours. Many of the epidemiological findings already observed for mucinous carcinoma were also confirmed. The existence of prognostic, clinical, and epidemiological differences between mucinous and nonmucinous colorectal carcinoma, together with the preliminary reports about their difference as to genetic features, could support the hypothesis that mucinous type is a distinct biological entity.