The role of endoscopic colon surveillance in the transplant population.

PURPOSE: Long-term immunosuppression increases the risks of developing certain malignancies. This study examines the effects of long-term immunosuppression on the development of metachronous adenomatous polyps and attempts to formulate a sound surveillance plan for these individuals.
METHOD: A retrospective analysis was performed of all solid organ transplant patients at Henry Ford Hospital from 1989 to 1999, with a specific focus on endoscopic evaluation and outcomes after three years of surveillance. Comparison was made to an age-matched and gender-matched control group from the same endoscopic database. Variables were compared using the chi-squared test, Fisher's exact probability test, and Hochberg's test.
RESULTS: A total of 992 solid organ transplants were performed. Two hundred twenty-nine (23 percent) of the transplant recipients underwent pretransplant colonoscopy, of which 178 patients (78 percent) were age 50 years or older. Seventy-four (32 percent) of the prescreened population had polyps, of which 45 patients (61 percent) had adenomas. Twenty-seven patients (36 percent) had synchronous polyps, of which 12 patients (16 percent) had synchronous adenomas. At 3-year follow-up 59 patients (80 percent) had metachronous polyps. Twenty-eight patients (38 percent) had metachronous adenomas. Eleven patients (15 percent) with hyperplastic polyps on initial colonoscopy developed adenomas. The control group consisted of 25 females and 50 males with a mean age of 65.5 +/- 1.1 years. Fifty-one patients (68 percent) had adenomas on endoscopy. Twenty-four patients (32 percent) had synchronous lesions, of which 13 patients (17 percent) had synchronous adenomas. Sixty-one patients (84 percent) developed metachronous lesions, of which 33 patients (43 percent) had metachronous adenomas at 3 years. There was no difference in the polyp size or histology between the two groups. There was no statistically significant difference between the transplant patients and the control group in all analyses.
CONCLUSION: Because of an equivalent incidence of adenomatous polyps compared with the general population, current screening criteria should be used in patients posttransplant. Transplant patients are not more likely to develop metachronous polyps than the general population. Therefore, posttransplant polyp surveillance should not be more frequent than currently recommended for nontransplant patients with adenomatous polyps.