Increased Risk of Advanced Colonic Adenomas and Timing of Surveillance Colonoscopy Following Solid Organ Transplantation

Background Detection and removal of colonic adenomatous polyps (CAP) decreases colorectal cancer (CRC) development, particularly with more or larger polyps or polyps with advanced villous/dysplastic histology. Immunosuppression following solid organ transplantation (SOT) may accelerate CAP development and progression compared to average-risk population but the benefit of earlier colonoscopic surveillance is unclear. Aims Study the impact of maintenance immunosuppression post-SOT on developmental timing, multiplicity and pathological features of CAP, by measuring incidence of advanced CAP (villous histology, size >= 10 mm, >= 3 polyps, presence of dysplasia) post-SOT and the incidence of newly diagnosed CRC compared to average-risk age-matched population. Methods Single-center retrospective cohort study of SOT recipients. Results 295 SOT recipients were included and were compared with 291 age-matched average-risk controls. The mean interval between screening and surveillance colonoscopies between SOT and control groups was 6.3 years vs 5.9 years (p = 0.13). Post-SOT maintenance immunosuppression mean duration averaged 59.9 months at surveillance colonoscopy. On surveillance examinations, SOT recipients exhibited more advanced (>= 10 mm) adenomas compared to matched controls (9.2% vs. 3.8%, p = 0.034; adjusted OR 2.38; 95% CI 1.07-5.30). Conclusion SOT recipients appear at higher risk for developing advanced CAP, suggesting that earlier surveillance should be considered.