Clinicopathologic variables affecting survival of distal colorectal cancer patients with macroscopic invasion into the adjacent organs

A total of 506 distal colorectal cancer patients were classified into two groups, to clarify the variables affecting survival of the patients with macroscopic invasion into the adjacent organs: 47 cases showed invasion (invasive group) while the other did not show invasion (noninvasive group). Differences between the invasive and noninvasive groups were found in eight variables; female, large tumor size, gross types 3 and 4, moderately or poorly differentiated adenocarcinomas and signet-ring cell or mucinous carcinomas, deep cancer invasion, lymphatic invasion, peritoneal and liver metastases, and curability B-C were found significantly more frequently in the invasive group. The survival curve of the former was significantly (P<0.05) lower than that of the latter. However, no significant difference was found between the survival curves of the patients with curability A (no residual tumors) in both groups. A multivariate analysis in the invasive groups revealed six variables to be significantly related to a good prognosis including a young age, females, a location above the peritoneal reflection, well differentiated adenocarcinoma, negative lymphatic invasion and curability A. Surgery with curability A should be performed to improve the survival in distal colorectal cancer patients with macroscopic invasion into the adjacent organs.