Testosterone metabolism in patients with advanced carcinoma of the prostate: A comparative in vivo study of the effect of oestrogen and anti-prolactin

Abstract

In the light of the high incidence of cardiovascular side effects with oestrogen therapy in patients with prostatic cancer, other medications altering androgen metabolism are under investigation. The influence of the anti-prolactin bromocriptin (CB157) on plasma kinetics of testosterone and on endogenous hormones was studied and compared with the effect of ethinyl oestradiol in 25 patients with prostatic carcinoma. Bromocriptine significantly suppressed both prolactin and testosterone, inhibited the transfer of androgen from the inner pool into the deep compartment and favoured its degradation. Ethinyl oestradiol decreased testosterone, LH and FSH, and prolonged the biological half-life of testosterone. The effects of bromocriptine on androgen metabolism might be of therapeutic value in patients with prostatic carcinoma.

Repositioning Dopamine D2 Receptor Agonist Bromocriptine to Enhance Docetaxel Chemotherapy and Treat Bone Metastatic Prostate Cancer

“…Interestingly, activation of prolactin receptor signaling has been associated with prostate tumorigenesis and cancer progression, leading to the hypothesis that the blockade of pituitary prolactin production by bromocriptine could benefit PCa patients (47). Indeed, several pilot trials have been performed in castration-resistant PCa (48–50), which showed that bromocriptine administration (for example, 2.5 mg, three times per day) was well tolerated and significantly reduced the plasma levels of prolactin and testosterone. However, the bromocriptine-associated responses varied among these studies from an overall objective regression of 22.2% (and 50% of the patients had a prompt relief of bone pain) to no complete or partial responses in evaluable patients.…”

Prolactin effect on the permeability of human benign hyperplastic prostate to testosterone

“…The general finding is that low-to-moderate levels of Prl potentiate the trophic effects of testosterone on prostatic growth but that, beyond optimal levels, the lactogen becomes an inhibitor of both normal and neoplastic growth. These relationships have clinical significance since there is an inverse relationship between survival and serum prolactin levels in prostatic cancer patients [ 1,2], and stabilization or remission of the disease has been found to follow prolactin depletion [3,4].…”

Drug-Induced Changes in Prolactin Secretion

“…Suppression of prolactin release by bromocriptine reduced the weight of androgen-dependent organs in animal studies . In addition, antiprolactins show an analgesiceffectin many patients with bone pain from skeletal metastasis (Jacobi et al 1978). The therapeutic use of prolactin-inhibiting substances in these patients is well established.…”