Effects of the new immunosuppressive agents on the occurrence of malignancies after renal transplantation

Introduction

The risk of malignancies in renal transplant recipients is considerably greater than in the general population. The purpose of the present study was to investigate the effects on the appearance of malignancies of 3 immunosuppressive periods: azathioprine (AZA), cyclosporine (CsA), and tacrolimus (TAC).

Patients and Methods

This study included 1029 first renal transplant recipients of mean age at transplantation of 44.6 ± 14.9 years with a mean follow-up of 95.6 ± 84.2 months. Initial immunosuppression was AZA-based (n = 198), CsA-based (n = 524), and TAC (n = 307). A total of 280 recipients were also treated with mycophenolate mofetil or mycophenolic acid.

Results

There were 157 patients (15.3%) who displayed ≥1 malignancy; there were 95 skin (9.2%) and 74 (7.8%) non-skin malignancies with presentations at 74 ± 62 and 107 ± 77 months, respectively (P = .003). The skin malignancies included squamous cell carcinomas (n = 41), basal cell carcinomas (n = 41), Kaposi sarcomas (n = 7), and melanomas (n = 4). Among the solid tumors, lymphoproliferative disorders (n = 15), digestive tract (n = 14), kidney and urinary tract (n = 11), lung (n = 10), and breast (n = 3) carcinomas. The cumulative incidences at 5, 10, and 15 years were 6%, 10%, and 18% for skin and 3%, 7%, and 14% for non-skin malignancies, respectively. Multivariate analysis showed that age at transplant in years (P = .000) and male gender (P = .000) were the only variables associated with skin malignancies; age at transplant in years (P = .004) and treatment with OKT3 (P = .000) were associated with non-skin malignancies. Malignancies were the cause of death in 18% of recipients who died with functioning grafts.

Conclusion

Malignancies are an important cause of morbidity and mortality among renal transplant recipients. The new immunosuppressive agents do not increase the risk of malignancies. Special surveillance is needed for older, male recipients.