What are the possible reasons for urethral PSA varieties after radical prostatectomy?

Objective: To examine the possible reasons for great varieties in urethral prostate specific antigen (urPSA) levels, in patients after radical prostatectomy (RP).
Materials and Methods: In 46 patients with pros-tate cancer, PSA, urPSA, total testosterone, body-mass index (BMI) and the stage of androgenic alopecia (AGA) were determined. Forty-five patients underwent retropubic RP, while one underwent cystoprostatectomy with orthotopic bladder construction, due to bladder cancer.
Results: Average patients age prior to surgery plus or minus standard deviation was 65.2 +/- 5.8 years. Average urPSA was 20.9 +/- 47.5 ng/ml (0.05 to 212 ng/ml, median 2.24 ng/ml). With urethral PSA cut-off of 2.0 ng/ml, two groups were formed: A (urPSA < 2.0 ng/ml) and B (urPSA = 2.0 ng/ml). Patients in the group A had significantly lower average AGA score, than the patients from the group B (2.4 +/- 1.3 vs. 4.4 +/- 2.2, p = 0.0003). In addition, patients from the group A had significantly lower pos-toperative PSA (0.07+0.08 ng/ml vs. 0.14 +/- 0.06 ng/ml, p = 0.0014).
Conclusions: The patients with higher urPSA have higher AGA scores and higher postoperative PSA. This phenomenon is probably the consequence of higher local dihydrotestosterone activity in the scalp and PSA-secreting urethral glands.