The study examined factors associated with prostate cancer occurrence in kidney transplant recipients. The analysis included 660 transplant recipients, of whom 623 (94.4%) had de novo prostate cancer and 37 (5.6%) had recurrent disease. Using statistical analyses, recipient age was identified as the only factor consistently associated with recurrent disease, with risk increasing by 11% per year of age. Immunosuppressive regimens, donor characteristics, immunologic variables, and time from transplantation to cancer diagnosis were not independently associated with disease phenotype. The findings suggest that the difference between recurrent and de novo prostate cancer is more closely associated with patient age and underlying disease characteristics than with transplant-related factors or specific immunosuppressive regimens.