Genitourinary tumor following kidney transplantation: a multicenter study.

Renal transplantation has been advocated as the treatment of choice for end-stage renal disease. Immunosuppression increases the incidence of cancer and promotes the growth of neoplasms in solid organ recipients. There have been a few reports on the incidence of cancer from transplant registries. It is difficult to precisely compare the incidence with that in the general population using data from small, single-center studies. Thus, we sought to study the prevalence of genitourinary cancer development in Iranian renal transplant recipients. We collected data from 5 kidney transplant centers in Iran between 1984 and 2008, seeking to detect the incidence, type, and outcome of cancers after kidney transplantation. Only histologically confirmed tumors, which occurred after renal transplantation, were included in the analysis. Of the 5532 patients who underwent kidney transplantation, genitourinary tumors were detected in 21 subjects (0.38%), namely, 12 males and 9 females. Transitional cell carcinoma (TCC) of the bladder, the most common genitourinary cancer (n = 7) was followed by renal cell carcinoma (RCC; n = 5), ovarian cancer (n = 3), breast cancer (n = 3), prostate cancer (n = 1), seminoma (n = 1), and uterine cancer (n = 1). The overall mean age of the patients was 46 +/- 12 years (range, 19-72 years) and the median time to diagnosis after transplantation was 72 months (range, 4-240 months). Seven patients died during the follow-up. There was a male predominance among TCC of the bladder and RCC (5:2 and 4:1, respectively). In conclusion, TCC of the bladder was the most common genitourinary tumor following kidney transplantation. It was predominant in male patients.