BACKGROUND AND AIM The aim of this study was to determine whether the prevalence of advanced colorectal neoplasms increases in kidney transplant recipients and to define the appropriate duration for surveillance colonoscopy after kidney transplantation (TPL).

METHODS Our study consisted of 248 kidney transplant patients who underwent a colonoscopy at Seoul National University Hospital from 1996 to 2008. For each patient, two or more age- and sex-matched controls were identified from a population of asymptomatic individuals.

RESULTS Twenty (8.1 %) patients had advanced colonic neoplasms, including colorectal cancers (four patients, 1.6 %), after kidney TPL. A case-control study showed that the odds of advanced colonic neoplasms occurring in TPL patients were 2.3 times greater than in the matched subjects. In addition, TPL patients 50 years of age or older had an approximate 5.4-fold higher risk of developing advanced neoplasms than did the matched subjects (OR 5.370; 95 % CI 2.543-11.336; P < 0.001). Age and history of advanced neoplasms were associated with an increased risk of developing advanced neoplasms after TPL. The 5-year cumulative incidence rate of advanced neoplasms was 3.6 % in the 82 patients with normal or non-advanced adenomas detected via screening colonoscopy before TPL.

CONCLUSIONS Colonoscopy is recommended for patients before and after kidney TPL, especially for those 50 years of age or older. Colonoscopy surveillance after TPL is warranted strictly according to the baseline risk stratification.