Gastrointestinal and Liver Malignancies after Renal Transplantation: A Multicenter Study

Background: Immunosuppression increases the incidence of cancer and promotes the growth of neoplasm in kidney transplant recipients. There have been few reports on the incidence of gastrointestinal (GI) and liver cancers from transplant registries.

Methods: In the current study, we collected data from 8 kidney transplant centers in Iran between 1984 and 2008, to detect the incidence, type, and outcome of GI and liver cancers after kidney transplantation. Only histologically confirmed tumors that occurred after renal transplantation were included in the analysis. We also compared their data with 3028 kidney recipients of two transplant centers.

Results: Of the 9355 patients who underwent kidney transplantation, GI tumors were detected in 14 (0.15%), 12 males and 2 females. Male gender was predominant between patients with GI and liver tumors (P=0.02). Colorectal carcinoma (CRC) was the most common GI cancer (n=7) followed by gastric adenocarcinoma (n=3) and hepatocellular carcinoma (n=3). Mean age of patients was 48.0 ± 10.6 (27 - 61) years and mean time of diagnosis since transplantation was 72 (5-284) months. Significant risk factors for the development of a de novo malignancy were male gender, older age (>50 years of age) and the total time on immunosuppression. Patient and graft survival rates from the time of GI and liver cancers onset were poor.

Conclusions: CRC was the most common GI tumor following kidney transplantation and was predominant in male. GI and liver malignancies have poor prognosis and early diagnosis and prompt treatment of the post- transplant malignancies is essential.