Testosterone level in seminal vesicle fluid is a better indicator of sexual function than serum testosterone in patients with prostate cancer

Abstract

ABSTRACT Objective Semen comprises prostatic fluid and seminal vesicle fluid, which makes up the largest proportion. Seminal vesicle fluid contains various factors such as prostaglandin E2 (PGE2), zinc, and testosterone, which play important roles in sperm motility. Although serum testosterone is important in sexual function, many points are unclear regarding correlations between serum testosterone level and erectile function. We hypothesized that testosterone in seminal vesicle fluid may affect sexual function. Methods After receiving institutional review board approval, we collected seminal vesicle fluid samples from 132 Japanese patients with localized prostate cancer who underwent robot-assisted prostatectomy at Kyushu University Hospital from May 2017 to August 2020. We examined the relationship between results of the Sexual Health Inventory for Men (SHIM), Erection Hardness Score (EHS), an original questionnaire (presence or absence of sexual desire), and concentrations of testosterone in seminal vesicle fluid as well as serum testosterone level. Results Median participant age was 68 (range 51–77) years. Median concentrations were as follows: seminal vesicle testosterone 1.85 (range 0.17–4.32) ng/mL, serum testosterone 4.59 (range 1.75–10.82) ng/mL. When SHIM score was divided into two groups, seminal vesicle testosterone concentration was significantly increased (P=0.001) in participants with SHIM score ≥17; no significant difference was observed in serum testosterone (P=0.716). EHS score was also correlated with seminal vesicle testosterone (P=0.031) but not serum testosterone (P=0.380). Multivariate analysis revealed that seminal vesicle testosterone was significantly correlated with SHIM score (≥17 vs. <17, odds ratio: 2.374, 95% confidence interval: 1.244–4.529, P=0.008). Seminal vesicle testosterone was not correlated with age (R2=0.032) or serum testosterone (R2=0.014). Conclusions Testosterone levels in seminal vesicle fluid can reflect sexual function in patients with prostate cancer, suggesting that seminal vesicle testosterone may affect male sexual function. Disclosure Work supported by industry: no.