The findings were published in the Journal of the American Society of Nephrology on Dec. 22, 2015.
“Screening recommendations for prostate cancer remain controversial, and no specific guidelines exist for screening in renal transplant candidates,” says Nicole Turgeon, MD, associate professor of surgery, Division of Transplantation, Emory University School of Medicine. “A PSA level may be elevated in a variety of disease processes, not only prostate cancer. Therefore, we wanted to see if PSA screening in patients with end-stage-renal-disease (ESRD) affected the time to transplantation and transplant outcomes.”
Using Emory’s Organ Transplant Tracking Record Database and electronic medical records, the researchers retrospectively analyzed 3,782 male patients 18 years or older undergoing primary renal transplant evaluation between Jan. 1, 2000 and Jan. 1, 2011. Patients were grouped by age per the American Urological Association Screening Guidelines: group one – patients less than 55 years of age; group two – patients 55 to 69 years of age; group 3 – patients greater than 69 years of age.
Out of 3,782 patients, 1,198 (31.7 percent) received kidney transplants. PSA screening was performed on 2,406 of the kidney transplant candidates (63.6 percent). PSA screening was associated with a significantly increased rate of prostate cancer diagnosis (3.2 percent non-screened versus 5 percent screened).
In this single-center retrospective study, the Emory researchers found that a positive PSA screening result (serum level greater than 4 ng/ml) was associated with significantly increased transplant waiting times in groups one and two. In candidates less than 55 years old, a positive PSA screening result was directly associated with a longer average time to listing (499 days for a positive PSA screening versus 221 days for no screening) and longer average time to transplantation (1,834 days for a positive PSA screening result versus 1,123 days for a negative PSA screening result). A similar pattern was observed in candidates ages 55 to 69, with a positive PSA screening result again associated with a longer average time to listing (339 days versus 85 days), and a longer average time to transplant compared with those who were not screened (1,355 days versus 781 days). There were no significant differences in time to listing or average transplant waiting times in group three.
“The negative effect on quality of life while awaiting a transplant may outweigh the benefits obtained by correctly diagnosing and treating prostate cancer, which offers no survival benefits to these patients,” says Turgeon, who is the director of the Kidney-Pancreas Transplant Program at Emory. “The ability to lead a normal life off dialysis is a privilege that many transplant candidates value most highly. Delaying that transplant by more than two years, in some cases, is a substantial effect, especially because two-thirds of patients die within five years of beginning dialysis. This is considerably higher than the 1.1 percent five-year mortality rate for prostate cancer.”
The researchers also found that a positive PSA screening result led to a diagnosis of prostate cancer in only 26.4 percent of candidates, although 75.8 percent of candidates with a positive PSA screening result did not receive a transplant.
Also of note, a false-positive result of a PSA screening, which occurred 74.6 percent of the time in this study, significantly delayed the listing for transplantation by nearly a year while candidates underwent further evaluation, without clear guidelines on how to manage an isolated elevated PSA level. This false-positive result also decreased the transplantation rate by approximately 50 percent.
“Our data demonstrate that PSA screening is not associated with an improvement in post-transplant patient survival,” explains Turgeon. “In fact, PSA screening may actually be harmful to transplant candidates.”