Macroscopic typing with wall stricture sign may reflect tumor behaviors of advanced colorectal cancers.

No appropriate macroscopic classification of advanced colorectal cancers (A-CRC) is available for assessing their tumor behavior. In the present study, A-CRC were classified macroscopically as either stricture or nonstricture type, and the differences in clinicopathological features, mode of recurrence, and prognosis between the two types were investigated. The subjects were 166 patients with A-CRC invading beyond the muscular layer who had undergone curative surgical resection. Fresh resected specimens from these patients were used for the study. The A-CRC were classified as of stricture or nonstricture type according to whether or not they showed marked fold convergence and/or stricture of the intestinal tract (more than 30% wall shrinkage) that had the appearance of a "bow tie". Of the 166 A-CRC, 47 (28%) were classified as stricture type. This type was significantly more frequent in the colon (37%; 37/101) than in the rectum (15%; 10/65) (P = 0.003). The stricture type was more frequently associated with an abundance of fibrosis than the nonstricture type (76%; 28/37 vs 39%; 25/64 in colon; P < 0.001; 100%, 10/10 vs 42%, 23/55 in rectum; P < 0.001). The recurrence rate was also higher in the stricture type than in the non-stricture type in both the colon (51%, 19/37 vs 17%, 11/64; P = 0.003) and rectum (80%, 8/10 vs 38%, 21/55; P = 0.01). The time to recurrence was significantly shorter for the stricture type in both the colon (P < 0.001) and rectum (P = 0.02). These results indicate that the macroscopic typing of A-CRC according to the presence or absence of wall stricture sign may reflect their tumor behavior, although this behavior appears to be complex and related to tumor progression. This classification could be important clinically to assess tumor behavior in a simple way.