Introduction Patients with primary sclerosing cholangitis (PSC) and co-existing colonic inflammatory bowel disease (IBD) have an increased lifetime risk of developing colorectal cancer (CRC); a risk that persists after liver transplantation.

Aim: Assess the incidence rate (I.R.) of colonic dysplasia and/or cancer in patients transplanted for PSC, and determine any factors specific to post-transplant care associated with an increased CRC risk.

Methods The cohort included all patients transplanted from 1987 to 2015 for PSC with concomitant colitis. Time zero was set as the point of first liver transplant. The study end-point was the time to first dysplasia or any higher lesion. Patients were censored at time of colectomy (for a non-CRC indication), death or last date of CRC-free follow up. Statistical methods employed for determining potential risk factors included Cox-proportional hazards and Kaplan-Meier estimates.

Results Overall, 306 patients were transplanted during this time period. 202 patients (66%) had underlying IBD and of this group 191 patients (95%) had co-existing colitis. The final study population was 163 patients who had colitis with an intact colon.

The I.R. of developing colonic dysplasia or higher lesions was 18.9 cases per 1,000 patient years and of colonic high grade dysplasia (HGD) or neoplasia was 10.4 cases per 1,000 patient years. There has been an increase in incidence rates by year of transplant (Table 1). No risk factors for the development of colonic dysplasia or above post liver transplantation were statistically significant. These risk factors included the number of colitis flares (>0, >1, >2), the use of cyclosporine (versus tacrolimus), the use of azathioprine (versus mycophenolate mofetil), thiopurine use, use of ursodeoxycholic acid, advancing age and male gender.

Conclusion The incidence of colonic dysplasia in the PSC post-transplant population is rising. Further review of specific colitis findings need to be evaluated in order to aid in any potential risk factors for CRC development.

Disclosure of Interest None Declared