Characteristic Clinical Behaviors of and Prognosis for Mucinous Adenocarcinomas in the Colon and Rectum

ABSTRACT

PURPOSE: The clinical significance of a mucinous-type colorectal adenocarcinoma is still controversial. Mucinous colorectal adenocarcinomas have been suggested to have distinct clinicopathologic features, i.e., early-onset, right-side dominancy, and poor prognosis. We aimed to verify the biological behaviors of and survivals for mucinous adenocarcinomas compared with non-mucinous adenocarcinomas. METHODS: Using a database of colorectal cancers at Asan Medical Center between 1989 and 2000, we enrolled 121 mucinous adenocarcinoma and 2,289 non-mucinous adenocarcinoma patients in this study. Clinical, pathological characteristics of and prognoses for mucinous adenocarcinomas were analyzed and compared with those for non-mucinous adenocarcinomas, retrospectively. The median follow-up period was 24 (0~113) months for mucinous adenocarcinomas and 32 (0~130) months for non-mucinous adenocarcinoma. RESULTS: Compared to non-mucinous adenocarcinomas, mucinous adenocarcinomas showed distinctive clinicopathologic features of early-onset (P<0.001), frequent family history (P<0.001), right-side dominancy (P=0.010), advanced stage at diagnosis (P<0.001), and common peritoneal seeding at diagnosis (P<0.001). The recurrence rate in the mucinous adenocarcinoma group was 45.2% during the follow-up period 21.6% distant metastasis, 14.3% peritoneal dissemination, 5.7% local recurrence, and 3.6% simultaneous local recurrence and distant metastasis. The five-year survival rates in stages II and III were 70% and 48.7%, respectively, for mucinous adenocarcinomas and 92% and 50.2%, respectively, for non-mucinous adenocarcinomas. This difference was statistically significant. CONCLUSIONS: Mucinous adenocarcinomas seem to have distinct biologic behaviors with different clinicopathologic features and poor prognosis. A surgical approach with a follow-up schedule considering the characteristics of mucinous adenocarcinomas is needed.