Colicinogeny in colorectal cancer.

Colicins, bacteriocins of Escherichia coli and related bacteria of Enterobacteriaceae family, form a very heterogeneous group of antibiotically active substances of proteinaceous material. Antitumorous effect of colicins have also been demonstrated experimentally. The large bowel has been found to be a site of their native action. Therefore, our work has been aimed at investigating colicinogenicity in patients with colorectal carcinoma. From a total number of 77 patients with colorectal carcinoma, colicinogenic Escherichia coli was found in 32 persons (41.6%), whereas from a total of 160 control clinically healthy persons, colicinogenic Escherichia coli was found in 102 persons (63.8%). The difference is statistically significant (p less than 0.05). The absence of colicinogenic Escherichia coli may be one of the factors contributing to the origin and development of colorectal carcinoma in some of the patients studied. Studies of patients with adenomatous polyps, members of colon cancer families, and large prospective studies of the general population will be necessary to prove this hypothesis.