Periprostatic venous androgen levels in a subset of patients with prostate cancer: An investigation into a novel role of testosterone in localized prostate cancer.

Abstract

341 Background: While androgens drive prostate cancer (PCa), studies of systemic levels in eugonadal patients have not shown a relationship with development or progression of PCa. This study characterizes the relationship between systemic, local venous, and tissue androgen levels to understand the regulation and influence of androgens on localized PCa. Methods: Peripheral & periprostatic venous blood & prostate tissue were collected from patients undergoing radical prostatectomy (RP). Androgen levels (testosterone (T) and dihydrotestosterone (DHT)) were assessed by mass spectrometry. PCa grade and stage, PSA, prostate volume, and periprostatic vein diameter (PPVD) on MRI were recorded. A second cohort of patients undergoing just prostate MRI (non-surgical) was assessed to investigate the relationship between PPVD and disease severity. Results: Samples were collected from 176 patients. Analysis identified a subset of patients with elevated periprostatic T (ppT) relative to systemic T (sT) including 25% with ppT/sT > 2, 14% with ppT/sT > 4, and 7% with ppT/sT > 10. Patients with ppT/sT > 4 had supraphysiologic T levels in the periprostatic venous blood (mean 4223ng/mL). These patients also had higher than predicted levels of tissue T and DHT (tT/sT of 0.48 vs 0.24 (p = 0.004) and tDHT/sT of 7.31 vs 4.72 (p = 0.011)). In the surgical cohort, PPVD was increased in patients with elevated ppT/sT levels (5.8mm vs 3.7mm, p = 0.013). In the biopsy cohort (n = 200), increased PPVD was associated with an increased risk of diagnosis of PCa (4.39mm vs 3.43mm p = 0.006) and clinically significant PCa (4.35mm vs 3.43mm p = 0.01). Conclusions: In a subset of patients with PCa, periprostatic venous T levels were highly elevated compared to peripheral levels. Tissue T and DHT were also increased, and MRI demonstrated increased PPVD. We hypothesize that collateralization of venous drainage from the gonadal vein leads to both high local T and dilated veins. In a biopsy cohort, increased PPVD was associated with an increased risk of diagnosis of any and clinically significant PCa, suggesting that high periprostatic androgen levels may play a role in development of PCa.