Clinicopathological study on poorly differentiated adenocarcinoma of the colon.

Clinicopathological characteristics and grading of poorly differentiated colon adenocarcinoma (Por) were discussed. A total of 1074 patients with colon cancer underwent surgical treatment at Kurume University Hospital in Fukuoka, between 1985 and 2005. Clinicopathological characteristics of 88 cases (8%) of Por and 986 cases (92%) of well differentiated tubular adenocarcinoma/moderately differentiated tubular adenocarcinoma (Tub1/Tub2) were studied. A multiple classification analysis showed that Por was more frequently observed in the right colon than Tub1/Tub2, and that the ratio of macroscopic types 3 and 4 was significantly higher in Por. Significant differences were also observed with regard to lymph vessel and perineural invasion. There were no significant differences between recurrence-free survivals of Por and Tub1/Tub2 after radical resection in Stages II and III. Recurrence of Por was significantly higher in peritonea and lymph nodes. These findings indicate that Por, which is generally considered to have a poor prognosis, has a similar recurrence rate to that of Tub1/Tub2 after the performance of radical surgery.