SUN-223 Impact of Testosterone Replacement Therapy (TRT) on Prostate Specific Antigen (PSA) in Patients with Clinical Evidence of Prostate Hyperplasia

Introduction/ Background Prostate cell growth is androgen dependent, so dogma holds that testosterone replacement therapy (TRT) can lead to the onset, progression, and unmasking of prostate problems. As a result, there continues to be a theoretical concern that TRT-induced proliferation of prostatic epithelial cells could result in benign prostatic hyperplasia (BPH), or prostate cancer. Although the intensity and frequency of monitoring prostate health during TRT remains controversial, a Prostate Specific Antigen (PSA) level >4 ng/ml is widely considered the cut-off at which urological evaluation should be sought. It is noteworthy that, despite a lack of conclusive evidence that TRT causes prostate cancer, Endocrine Society guidelines show an abundance of caution in recommending prostate cancer screening with PSA and DRE 3 to 12 months after treatment initiation followed by race- and age-appropriate monitoring after 1-year in patients who agree to prostate cancer monitoring after shared decision making. One unfortunate consequence of such vigilance is a reported increase in prostate biopsies for patients on TRT with PSA elevations. Although the merits of such vigilance might be debatable, the consensus appears to be that TRT does not cause prostate cancer, as much as unmask pre-existing subclinical prostate cancer, reflecting confirmation bias. An even more vexing issue is whether PSA monitoring might exaggerate the appearance of risk, given that it is more strongly associated with BPH than prostate cancer. Objective To compare the incidence of PSA >4 ng/ml during TRT in veterans with a pre-existing elevation in PSA or with a prior clinical diagnosis of BPH, versus those without elevated PSA or BPH. Design A retrospective cohort study of male veterans prescribed TRT between 2008 and 2014. Results Patients without a clinical diagnosis of BPH prior to initiating TRT were much less likely to develop PSA >4 ng/ml on TRT (16/746 [2.1%]) compared to those with prior BPH (19/222[8.5%], p=0.00007). Similarly, only 3% (22/879) of patients with PSA <4 ng/ml prior to TRT initiation developed a PSA >4 ng/ml on TRT, whereas ten of the fourteen patients (71.4%) who were prescribed TRT despite PSA >4 ng/ml continued to have a persistent elevation in PSA on TRT (P<0.00001). Surprisingly, PSA in four of the fourteen patients (28.6%) with PSA >4 ng/ml prior to TRT initiation declined to <4 ng/ml on TRT. Conclusions: Patients with PSA <4 ng/ml and no prior BPH are very unlikely to develop PSA >4 ng/ml on TRT. Even in patients with a prior PSA >4 ng/ml, further elevations were not seen on TRT, with a few even experiencing a decline in PSA to <4 ng/ml. We conclude, therefore, that the risk of developing PSA >4 ng/ml on TRT is small in the absence of either a prior diagnosis of BPH or PSA >4ng/ml. Urological outcomes remain uncertain, but need to be determined to better inform monitoring guidelines.