[Cancer of the colon and cholelithiasis: bile bacteria, composition of the stones and the bile].

Our recent studies have shown a significant association between lithiasic biliary disease and colorectal cancer. This could be due to the existence of risk factors common to both disease or to a cause-effect correlation between them. This latter hypothesis is supported by the observation in gallstone patients of the increase of biliary and fecal concentrations in secondary biliary acids. These could have co-carcinogenic effect on the colon. With a view to singling out further elements which might help us to understand more clearly the possible cause-effect correlation between cholelithiasis and colon cancer, we examined 12 patients affected by both diseases. In these, we evaluated the composition of the gallbladder stones, by means of spectrophotometry and diffractometry. Bile samples were taken from the gallbladder and used to examine the lipidic composition and the cholesterol saturation index according to Carey. In addition bacteriological examinations were carried out. The results were compared with those of 10 patients with cholelithiasis but not cancer, 10 with cancer but not cholelithiasis and 10 with neither. Analysis of the results did not reveal significant differences in gallstone and bile composition between colon cancer patients with concomitant gallstones and control groups. However, in cancer patients with gallstones a higher incidence of bile bacteria (35.7%) was observed than in the other groups. Bile bacteria were observed more frequently in right colon cancer patients who had pigment stones in 75% of the cases. The results seem to evidence peculiarities in patients with a cancer of right colon.(ABSTRACT TRUNCATED AT 250 WORDS)