Introduction: All transplants are associated with an increased lifetime risk of malignancy due to immunosuppression. Given the higher level of immunosuppression in intestinal transplant (ITx), there is a concern this risk may be considerably higher in this group of patients. In kidney transplant recipients this risk has shown to be three times higher than a baseline population in the recipient’s lifetime, but the risk of de novo malignancy has never been quantified after ITx.
Method: A retrospective study was conducted from both centres performing adult ITx in the United Kingdom. Records from intestinal transplant recipients from 01/01/2015 to 01/04/2024 were reviewed to ascertain the occurrence of transplant de novo malignancies. Post-transplant lymphoproliferative disorder (PTLD) and patients who had progression of their primary malignancy were excluded in the final analysis.
Results: 140 ITx were performed across both sites in this period. The mean age of recipients was 44.5. Distribution of ITx types were: 53% isolated small bowel, 18% liver-small bowel, 12% modified multivisceral, 17% multivisceral. Indications were loss of vascular access, liver disease, Porto mesenteric thrombosis and re-transplantation.
Of these, 18 patients developed 25 malignancies. The main categories were skin (33%), cervical (12%), haematological (8%), lung (8%) and gastric (8%).  The distribution of these malignancies can be seen in Figure 1. Out of ITx patients who developed de novo malignancies 17% also developed PTLD. The mean age of diagnosis was 54 years. There was a 61% incidence of previous smoking in the group, although no one was a current smoker. The 5-year survival rate of the 18 patients was 33% compared to the overall published 5-year survival rate in the UK post intestinal transplant of 62%. The malignancy was the cause of death for 55% (n=10) of the 18 patients.

Conclusion: From analysing retrospective data of all adult intestinal transplant patients, the rate of non-PTLD malignancy is 13% post ITx transplant. This rate of de novo malignancy and subsequent poor outcomes should prompt careful counselling. Harm reduction such as UV protection, smoking cessation and regular follow-up should be undertaken. Further assessment of risks factors for developing malignancy should be conducted in this patient’s cohort to help further stratify individual risk for developing malignancy.