PSA-BASED SCREENING FOR PROSTATE CANCER AFTER RENAL TRANSPLANTATION (2000)

Immunosuppressive treatment after organ transplantation is associated with an increased incidence of malignancy. In addition, increased graft survival rates will result in a larger number of patients reaching the age group at risk for prostate cancer, the most frequent cancer in men. However, in the absence of a screening procedure, a rather low incidence of prostate cancer (1.8%) was reported among 389 renal transplant recipients (1). In the largest series of prostate cancer in renal transplant recipients published to date, only 16 cases were reported, underestimation in diagnosis was suggested and screening was strongly advocated (2). We report our 1998 experience of PSA screening (Hybritech Tandem-R assay) in 120 consecutive male renal transplant recipients >50 years (median 61, range 50–74), receiving transplants between 1986 and 1996 and receiving cyclosporine A-based immunosuppressive therapy in addition to steroids and azathioprine (Fig. 1Figure 1: Distribution of PSA values in the serum of 120 male renal transplant recipients, according to age. The horizontal line (4 ng/ml) represents the threshold used for indicating sextant biopsies. o : patients with PSA values <4 ng/ml who were not submitted to further investigations; ⋄ : patients who declined further investigations; ▪ : patients presenting with prostate cancer on sextant transrectal biopsies; □ : patients with negative sextant biopsy results.). All patients had induction therapy with polyclonal antilymphocytes antibodies. Eleven patients (9.2%) for whom PSA values exceeded the threshold value (4 ng/ml) were proposed for digital rectal examination and sextant transrectal biopsies, that is, transrectal ultrasound-guided biopsies. Two patients declined examination and a biopsy. When one of them was reviewed 6 months later, the PSA had increased from 24 to 116 ng/ml, which was evocative of advanced cancer, and later biopsies confirmed this diagnosis. Among the nine patients who accepted biopsies, inflammatory lesions were evidenced in one, benign prostatic hyperplasia in one, and prostate cancer in seven. In the latter, the mean Gleason score was 6 (range : 5 - 7). The resulting detection rate was 5.8% (7 of 120 patients). Median time since transplantation was 84 months (range 14–156 months) in cancer patients. Digital rectal examination was abnormal in four patients and unremarkable in three patients, bone scan was normal in all seven. One patient declined any surgical procedure and was clinically classified as T2b according to the joint TNM-AJCC classification (3). In four patients, lymphadenectomy opposite the graft was performed for staging and proved to be negative (pNO), clinical staging was T1c in 1 patient, T2a in 2 patients, and T2b in 1 patient. All five patients were then submitted to 3D-conformal radiotherapy after adjuvant hormonal deprivation. In two patients, radical prostatectomy with lymphadenectomy (pNO) was performed; pathologic staging was pT2a with negative margins in both cases. In all seven patients graft function, as evidenced by creatinine clearance, was unchanged by cancer treatment and immunosuppressive therapy regimens were not modified. PSA values were above the threshold in roughly 10% of the patients, in line with the results observed in other screened populations of similar ages, such as in the European Randomized Study of Screening for Prostate Cancer (age selection 55–74) (4). In the Belgium and Netherlands arms of this study, the sextant biopsies performed in patients with PSA > 4 ng/ml were of moderate diagnostic yield and detected cancer in 65 of 206 patients (31.5%) and 131 of 472 (27.8%) patients, respectively (4). It is surprising that in our series, biopsy results were positive in seven of nine renal transplant recipients (77.7%). The Fisher exact chi-square test showed that this percentage of positive biopsy results was significantly higher than those reported in the above mentioned arms (P =0.007 and P =0.002, respectively). In conclusion, the detection rate in this series showed a high incidence of prostate cancer (5.8%), supporting the fact that prostate cancer prevalence in renal transplant recipients is underestimated in the absence of screening. Moreover, in this particular population, this experience highlighted, the high diagnostic efficacy of sextant biopsies after PSA screening. Whereas prostate cancer screening is still debated for the general population, we recommend its use in the follow-up of patients after renal transplantation. Bernard Malavaud Madeleine Hoff Marcel Miédouge Lionel Rostaing