[Labeling index in colonic cancer, polyps and polyposis and nonspecific colitis]

Thymidine historadiography was employed to study labelling index in tumors and grossly-unaltered mucosa of large bowel in 34 cases of colorectal cancer and 67 patients with single polyps, polyposis and villous tumors of large bowel and suffering from nonspecific colitis. Mean labelling index in tumor tissue was established at 5.49, in normal mucosa of large bowel of healthy subjects--1.19, and in colitis, polyps and villous tumors--2.32, 4.24 and 5.84%, respectively. Labelling index increased with the degree of pathologic changes in mucosal epithelium of large bowel. Thymidine historadiography should be used in formation of groups at risk for large bowel cancer.