Change in Prostate Specific Antigen Following Androgen Stimulation is an Independent Predictor of Prostate Cancer Diagnosis

A new era of testosterone and prostate cancer: from physiology to clinical implications

CONTEXT

Decades-old beliefs regarding androgens and prostate cancer (PCa) have undergone dramatic shifts in light of modern evidence and new theoretical constructs, but considerable confusion remains on this topic, particularly with regard to the use of testosterone therapy in men with any history of PCa.

OBJECTIVE

To review current literature regarding the relationship of serum testosterone on PCa and in particular the effect of testosterone therapy on PCa progression and recurrence.

EVIDENCE ACQUISITION

A Medline search was conducted to identify all original and review articles assessing the effect of androgens on the prostate and the use of testosterone in men with a history of treated and untreated PCa.

EVIDENCE SYNTHESIS

Contrary to traditional teaching, high endogenous serum testosterone does not increase the risk of developing PCa, and low serum testosterone does not protect against PCa. Although limited in size and duration, current studies similarly fail to indicate any increased risk of PCa in men receiving testosterone therapy. These results indicate a finite ability of androgens to stimulate PCa growth (the saturation model). A majority of studies demonstrate an association between low serum testosterone and poor prognostic features of PCa, including high-grade disease, advanced pathologic stage, and increased risk of biochemical recurrence following radical prostatectomy. The prostate-specific antigen-to-testosterone ratio predicted PCa risk in several biopsy studies. Multiple reports of testosterone therapy in men after treatment for localized PCa have shown low or absent recurrence rates. Some men with untreated PCa have received testosterone therapy without evidence for PCa progression.

CONCLUSIONS

The long-held belief that PCa risk is related to high serum androgen concentrations can no longer be supported. Current evidence indicates that maximal androgen-stimulated PCa growth is achieved at relatively low serum testosterone concentrations. It may therefore be reasonable to consider testosterone therapy in selected men with PCa and symptomatic hypogonadism.

Risques prostatiques de la testostérone : nouveau retour du balancier?

Depuis les années 1940, la testostérone (T) est réputée dangereuse pour la prostate, bien que sans preuve solide. Les études longitudinales ne montrent pas de corrélation entre taux de T et incidence des cancers de la prostate (CaP), dont les formes graves sont au contraire associées à des taux faibles de cette hormone. Les essais cliniques randomisés contre placebo de traitement par la T n’ont pas montré d’augmentation de l’incidence du CaP dans les groupes T. Ces données rassurantes ont conduit certains à prescrire des traitements de substitution androgénique à des hommes porteurs de néoplasies intra-épithéliales prostatiques, ou précédemment traités pour un CaP de bon pronostic, ou sous surveillance active pour un tel cancer non traité, sans qu’apparaisse un risque élevé de progression ou de récidive du CaP sous ce traitement. Il ne fait pourtant aucun doute que la prostate normale et son cancer, au moins dans ses formes évoluées, sont faits de tissus androgénodépendants. Ces apparentes contradictions pourraient s’expliquer, outre par la possibilité d’une très faible diffusion de la T circulante dans le tissu prostatique, par l’hypothèse d’une saturation des récepteurs androgéniques prostatiques dès des niveaux très bas de T circulante, proches des taux de castration, expliquant qu’une augmentation de la T au-delà de ce niveau ne puisse pas stimuler le tissu prostatique. Quelques publications récentes d’évolution de CaP sous traitement androgénique, persistant parfois à l’arrêt de ce traitement, montrent qu’on ne peut pas généraliser les résultats très favorables des études précédentes. Des données objectives suggèrent aussi que le niveau de saturation du récepteur androgénique prostatique pourrait être en réalité proche de la limite inférieure des taux physiologiques de T. Il faut donc rester prudent avant d’élargir les indications du traitement par la T chez les hommes avec antécédent de CaP. Seules des études randomisées à grande échelle, en double insu contre placebo, permettront de se faire une idée exacte des risques auxquels expose ce traitement.

Standards for clinical trials in male sexual dysfunctions

INTRODUCTION

Clinical trials in male sexual dysfunction (MSD) are expanding. Consequently, there is a need for consensus standards in this area.

AIM

To develop an evidence-based, state-of-the-art consensus report on standards for clinical trials in MSD.

METHODS

A literature review was performed examining clinical trials in erectile dysfunction (ED), premature ejaculation (PE), delayed/absent ejaculation, libido disorders/loss of desire, hypogonadism, and Peyronie's disease, focusing on publications published in the last 20 years. This manuscript represents the opinions of eight experts from seven countries developed in a consensus process. This document was presented for peer review and debate in a public forum and revisions were made based on recommendations of chairpersons to the International Consultation on Sexual Medicine.

MAIN OUTCOME MEASURE

Expert opinion was based on the grading of evidence-based medical literature, widespread internal committee discussion, public presentation, and debate.

RESULTS

According to experience and recent publications in dealing with clinical trials in sexual dysfunction, recommendations have been made for conducting trials in patients with ED, PE, delayed ejaculation, libido disorders, hypogonadism, and Peyronie's disease.

CONCLUSIONS

It is important that future clinical trials are conducted using standards upon which investigators can rely when reading manuscripts or conducting new trials in this field.

Association between serum sex hormone levels and prostate cancer: effect of prostate cancer on serum testosterone levels

Androgens are essential for prostatic growth and development, but also play a significant role in the pathogenesis of prostate disease. The traditional view that higher testosterone levels represent a risk factor for prostate cancer (PCa) appears to have little evidentiary support. Some studies have described a relationship between lower testosterone levels and more advanced disease. Serum androgen levels, within a broad range, are thus suggested to show no association with PCa risk, whereas low rather than high serum testosterone levels have been found to be associated with advanced or high-grade disease at the time of PCa diagnosis. Dihydrotestosterone, the principal prostatic androgen, is transformed from testosterone by type 1 and type 2 5alpha-reductase, and therapeutic benefits may thus be potentially achieved through the inhibition of 5alpha-reductase.