The relationship between cholecystectomy and colon cancer: an Iowa study.

The relationship between cholecystectomy and subsequent development of colon cancer was investigated in a case-control study of 165 patients with histologically proven adenocarcinoma of the colon. These patients were from a community in Iowa where incidence of colon cancer was considered to be higher than average in the United States. The relative risk of developing colon cancer after cholecystectomy was shown to be 2.11 (P = .009) for the entire series and 2.91 (P = .002) for the female group. There was a difference of frequency in developing colon cancer after cholecystectomy between the right- and left-sided colons; the relative risk of the right versus the left colon cancer was 2.31 (P = .019). The other factors, including blood group, red cell indices, obesity, serum cholesterol, colonic diverticula, and co-existence of hyperplastic or adenomatous polyp disclosed no significant relation to colon cancer developed after cholecystectomy.