Utility of Pre-Liver Transplant Screening Colonoscopy

Liver transplant (LT) is the treatment of choice for patients with end-stage liver disease. Recent improvements in LT outcomes are related to advancements in operative techniques, management of transplant rejection with newer and better immunosuppressive agents, and careful selection of LT recipients. The American Association for the Study of Liver Disease practice guidelines for LT include screening for extra hepatic malignancies before transplant because of the concern that immunosuppression may accelerate the growth of preexisting cancers or trigger latent recurrent disease in those with a past history of malignancy.1 Although LT patients have an increased risk for other malignancies, it is unclear whether these patients have an increased risk of colorectal cancer (CRC) compared with the general population.2, 3 Pretransplant colonoscopy with polypectomy and biopsy, as indicated, has been established as the standard of care in LT candidates, and is required by most insurance providers before listing for transplant. The goal of this study is to establish the incidence of pretransplant colorectal disease from a large cohort of LT patients and to determine the incidence of CRC in the posttransplant period. The study population consisted of patients undergoing LT at the Indiana University Hospital between 2001 and 2015. Data collection included patient demographics, etiology of liver disease, date and findings of colonoscopy, and pathology reports. The protocol for CRC screening at our center requires a colonoscopy within three years of listing for LT. There is no specific posttransplant screening protocol, other than the standard of care for the community. Incidence of advanced adenomas (villous or serrated histology and moderate or high-grade dysplasia) and colon carcinoma are reported as events. Extracted medical records came from the comprehensive transplant recipient registry at our center, and individual written and electronic medical records. Recipient inclusion criteria for this study included all transplant recipients aged 18 years and older receiving a deceased donor liver allograft at our center. Minimum follow-up time was 12 months. Median death-censored follow-up time posttransplant was 72 months. In patients receiving retransplantation, the first and older listing of the patient in the database was removed during the analysis to avoid double counting events. The immunosuppression protocol includes induction therapy with rabbit antithymocyte globulin and steroids, followed by tacrolimus monotherapy.4 Statistical analysis was performed using commercially available software (IBM SPSS Statistics 24; IBM Corporation, Armonk, NY). The Cox proportional hazards model was constructed using a direct entry method. Covariates were included in this model for a P-value < 0.10 or if the P-value was felt to be clinically significant. Graft and patient survival outcomes, and other categorical variables, were analyzed using the chisquared test. Continuous variables were analyzed with one-way analysis of variance testing. Statistical differences were considered significant for a P-value < 0.05. The study protocol conformed to the ethical guidelines of the 1975 Declaration of Helsinki. The records of 1685 LTs were reviewed. Among these patients, nine were found to have any pre-LT history of colon or rectal cancer. There were nine (all different) patients who developed de novo post-LT colon or rectal cancer (0.5%). Analysis of patient demographics included a review of age, gender, race, body mass index, primary diagnosis, model for endstage liver disease score, and history of alcohol abuse or tobacco use. Among these factors, there were no significant differences between patients who did or did not develop pre-LT or post-LT CRC, except that the patients with a history of pre-LT CRC were older (62 vs 55 years, P < 0.01) (Table 1). Address correspondence and reprint requests to Richard S. Mangus, M.D., M.S., Department of Surgery, Indiana University School of Medicine, 550 North University Boulevard, Room 4601, Indianapolis, IN 46202. E-mail: rmangus@iupui.edu.