Does Cholecystectomy Affect Colonic Tumorigenesis?

• To determine if cholecystectomy predisposes to colon cancer, a study of this operation's influence on chemically induced murine colonic neoplasia was conducted. One hundred mice underwent cholecystectomy or a sham operation. Equal groups received either ten weekly injections of 1,2-dimethylhydrazine (DMH) or injections of saline. Twenty-four weeks after operation, the site, histologic findings, and number of tumors were noted. Crypt metaphase index (CMI) and proliferative zone size (PZS) determinations served as markers of preneoplasia. Tumors were found in the majority of animals receiving DMH while no tumors were found in the saline groups. Both CMI and PZS were significantly increased by DMH administration. Within the saline groups, cholecystectomy increased CMI and PZS two and three times, respectively, over levels seen in the sham-operated animals. This suggests that cholecystectomy alone induces preneoplastic changes in the murine colonic crypt.