De novo gastrointestinal tumours after renal transplantation: role of CMV and EBV viruses.

The development of new and more effective immunosuppressive agents has provided long-term survival for transplant recipients, thereby increasing the risk of de novo malignancy in chronic immunocompromised hosts. While de novo post-transplant lymphoproliferative diseases and skin cancer has been shown to have an increased incidence in long-term surviving solid organ transplant recipients, the association with gastrointestinal (GI) cancer is controversial. Over 12 yr, 20 patients (5%) out of 395 renal transplant recipients developed 23 de novo tumours; 11 skin cancer and 12 non-skin cancer. Four patients (1%) developed de novo tumours of the GI tract (three colon, and one gastric cancer). Immediately after tumour's diagnosis, immunosuppressive therapy was reduced; all patients were shifted from cyclosporine to Rapamicine within 30 d. The tumour was surgically resected with curative intent in three cases, while one patient had only palliative surgery because of metastatic disease. The post-operative courses was uneventful. All patients maintained normal graft function. However, three out of four patients (75%) died of progression of the neoplasm, within a median time from the diagnosis of 12 months. Further, we investigated a possible correlations between de novo GI cancer and HCV, HBV status, infections, cytomegalovirus (CMV) and Epstein-Barr virus (EBV) reactivation, episodes of rejection, and blood transfusions. All cases with GI de novo cancers reported in this paper developed CMV and EBV reactivation within three months after transplantation. Thereafter we suggest a closer follow-up for de novo GI cancer in renal transplants with early CMV and EBV reactivation in order to avoid delayed diagnosis.