Colorectal Cancer Characteristics and Outcomes after Solid Organ Transplantation

BACKGROUND: Individuals after solid organ transplant may develop secondary malignancies. In our clinical practice, we noted an increasing number of individuals who developed colorectal cancers after solid organ transplantation. The primary aim of this study was to describe the characteristics and outcomes of the patients who developed colorectal cancer after solid organ transplant. MATERIALS AND METHODS: Data was gathered and merged from several registries at Mayo Clinic to identify all patients who received a diagnosis of colon or rectal cancer and solid organ transplant. Continuous variables were summarized as mean (standard deviation) and median (range), while categorical variables were reported as frequency (percentage). Time to colorectal cancer after transplant and overall survival after cancer diagnosis were estimated using Kaplan-Meier method. RESULTS: Initially, 115 colorectal cancer patients who also had a transplant were identified. The diagnosis of colorectal cancer was noted after solid organ transplant in 63 patients. The mean age at transplant was 57 years. Majority had received a kidney transplant (44.4%) followed by liver (36.5%). The median time to develop colorectal cancer was 59.3 months (range: 4.4-251.4 months). 15 (24.6%) were stage 4 at diagnosis and 13 (21.3%) had stage 3 colorectal cancer. Median overall survival was 30.8 months; 5-, 10- and 15-year survival were noted to be 42.5%, 17.9%, and 7.5%, respectively. None of the stage 4 patients were alive at 5 years; 5-year survival rate for stage 1, 2, and 3 patients was 77%, 50%, and 42%, respectively. CONCLUSIONS: Our study reports on one of the largest cohorts of patients of colorectal cancer that developed the cancer after solid organ transplant. Survival is extremely poor for advanced cases. However, long-term survivors are noted who developed the cancer at a relatively early stage. Colorectal screening recommendations may need to be revised for patients after solid organ transplant.