[Is cholecystectomy a risk factor for colorectal cancer? A meta-analysis].

The number of patients subjected to cholecystectomy has increased since the introduction of laparoscopic methods. Therefore, the question of an association between colorectal cancer (CR-Ca) and cholecystectomy (CHE) is again topical. Several studies have been performed investigating the possibility of a link between cholecystectomy and large bowel cancer. The findings recorded in these studies have been varied and in some cases contradictory. In meta-analyses of the different types of studies (prospective and retrospective) the main question, "Is the risk of colorectal cancer higher after cholecystectomy?" was examined. In prospective matched-pairs studies, 1158 patients who had undergone CHE were compared with 1222 controls. The relative risk (RR) was 1.48, and this result was not significant. The four prospective cohort studies compared the frequency of CR-Ca of 22,783 CHE patients with the expected frequency in the population (RR = 0.99). The retrospective studies compared the frequency of previous CHE in 11,797 patients with CR-Ca with the frequency in 33,940 controls without CR-Ca. The calculated odds ratio (O. R.) of the meta-analysis was 1.15, a significant but not clinically relevant increase in risk. Similar results was shown for evaluation of sex difference both in the prospective studies, with an RR of 0.99 for women and 1.00 for men, and in the retrospective studies, with a RR of 1.17 (p < 0.05) for women and 1.09 (n.s.) for men. The results for different location of the tumour show no significant risk differences in prospective studies either for the colon or for the rectum.(ABSTRACT TRUNCATED AT 250 WORDS)