Dihydrotestosterone administration does not increase intraprostatic androgen concentrations or alter prostate androgen action in healthy men: a randomized-controlled trial

Effect of testosterone replacement therapy on lower urinary tract symptoms: A systematic review and network meta-analysis

OBJECTIVE

In this study, we aimed to perform a network meta-analysis (NMA) to investigate the effects of different testosterone replacement therapy (TRT) administration routes on lower urinary tract symptoms (LUTS) in aging men with late-onset hypogonadism (LOH).

METHODS

A systematic search of PubMed, Embase, The Cochrane Library, CNKI, WanFang Data, and VIP was conducted to identify randomized controlled trials (RCTs) reporting data on International Prostate Symptom Score (IPSS), prostate-specific antigen (PSA) level, or prostate volume. NMA was performed, and subgroup analysis was conducted to assess the impact of TRT duration on outcomes.

RESULTS

A total of 21 RCTs involving 2453 participants were included. For pairwise meta-analysis, p values for TRT delivered by transdermal, intramuscular, and oral routes were as follows: IPSS: 0.93, 0.20, and 0.76; PSA level: 0.20, 0.27, and 0.98; prostate volume: 0.18, 0.04, and 0.16. There were no significant differences in IPSS, PSA level, or prostate volume between TRT routes. In subgroup analysis, long-term intramuscular TRT significantly decreased IPSS (p = 0.03), short-term transdermal TRT increased PSA levels (p < 0.001), and short-term intramuscular TRT increased the prostate volume (p = 0.04). Other forms of TRT showed no significant change in IPSS, PSA level, and prostate volume compared with the placebo. Indirect comparison of the three administration routes demonstrated no significant differences in IPSS, PSA level, and prostate volume. Nevertheless, surface under the cumulative ranking curve analysis indicated that intramuscular TRT had an 83% probability of being the best method for decreasing IPSS.

CONCLUSIONS

The results demonstrate that TRT does not worsen LUTS regardless of the administration route. Intramuscular TRT may be the preferred treatment for aging men with LOH and LUTS. Intramuscular TRT may be the preferred treatment for men with LOH and LUTS. Further research is warranted to validate these findings and optimize TRT management strategies.

Syzygium malaccense leaves methanol extract modulate some biochemical and inflammatory markers and prostate histology of testosterone-estradiol valerate induced benign prostatic hyperplasia in rats

Objective

The effect of Syzygium malaccense methanol leaf extract (SMLE) on some parameters of testosterone-estradiol valerate induced benign prostatic hyperplasia (BPH) in rats was assayed.

Materials and Methods

Thirty male albino rats were used and they were grouped as: Control: received 1 mL/kg olive oil (oral and subcutaneous); BPH: received subcutaneously 9 mg/kg dihydrotestosterone (DHT)+0.9 mg/kg estradiol valerate (ESV) and orally 1 ml/kg olive oil; finasteride: received 9 mg/kg of DHT+0.9 mg/kg ESV (subcutaneously) and 5 mg/kg finasteride (orally) and test groups 1 and 2: received 9 mg/kg of DHT+0.9 mg/kg ESV (subcutaneously) and 200 and 400 mg/kg SMLE (orally). The duration of the treatment was 28 days.

Results

The BPH group had increased prostatic total proteins, oxidative stress, interleukin 8, tumor necrosis factor-α, prostate weights, serum concentrations of prostate specific antigen, estradiol, follicle stimulating hormone, and C-reactive protein, dyslipidaemia, altered prostate histology and hormonal levels but had no significant change (p>0.05) in haematological indices relative to the control. Finasteride or S. malaccense modulated most of these parameters as corroborated by prostate histology. Acute toxicity study indicated the non-toxicity of SMLE. SMLE showed strong in vitro antioxidant activity which corroborated its in vivo antioxidant activity.

Conclusion

The study showed that S. malaccense could be useful in the management of BPH.

Effects of Androgen Treatment on Growth in Patients with 5-α-Reductase Type 2 Deficiency

BACKGROUND

Patients with 5-α-reductase type 2 deficiency (5αRD2) require androgen treatment for the growth of normal male external genitalia. Since limited research has been conducted on the effects of androgen treatment on height in individuals with 5αRD2, we investigated the effect of androgen treatment on bone age (BA) and the height status in children with 5αRD2.

METHODS

Of the 19 participants who were followed up for an average of 10.6 years, 12 received androgen treatment. BA and height standard deviation scores (SDS) were compared between the treatment and non-treatment groups, as well as between the dihydrotestosterone (DHT) and testosterone enanthate (TE) treatment groups.

RESULTS

Despite the above-average height of the 19 patients with 5αRD2, the height SDS relative to BA (htSDS-BA) was below average, particularly in the androgen treatment group. DHT treatment did not lead to an increase in BA or htSDS-BA, whereas TE treatment resulted in BA advancement and decreased htSDS-BA, especially in the prepubertal period.

CONCLUSIONS

DHT treatment is more favorable for height than TE treatment in patients with 5αRD2, particularly during the prepubertal period. Therefore, age and the type of androgen used should be carefully considered to minimize the risk of height reduction in these patient groups.

Longitudinal clinical course in patients with 5α-reductase type 2 deficiency treated with testosterone and dihydrotestosterone during infancy and puberty

5α-reductase type 2 (5αRD2) deficiency is a 46,XY disorder of sex development caused by impaired conversion of testosterone (T) to dihydrotestosterone (DHT). Penile enlargement therapy is important for male patients with 46,XY 5αRD2 deficiency who have undermasculinized external genitalia, such as severe micropenis. High-dose T and percutaneous DHT replacement are reportedly efficacious for penile enlargement in patients with this disorder. We presented herein the longitudinal course of four patients with 46,XY 5αRD2 deficiency who received T and DHT. T replacement therapy during infancy increased the stretched penile length (SPL) in three of the patients but was ineffective in one patient. DHT was administered to the three patients after T replacement therapy and further increased the SPL. During and after puberty, two patients asked for and received T replacement therapy, which contributed to increasing their SPL. A semen test in one patient with T replacement therapy at age 27 years revealed cryptozoospermia despite normal testicular volume. The clinical course of our patients during infancy indicated that DHT therapy may be preferrable to T replacement therapy for penile enlargement in patients with 5αRD2 deficiency. During and after puberty, T replacement therapy promoted penile enlargement possibly because of increased conversion of T to DHT via increased 5α-reductase type 1 activity even in patients in whom it was ineffective during infancy. In conclusion, DHT is effective for penile enlargement during infancy in patients with 5αRD2 deficiency while T replacement therapy is a viable option during puberty.

Androgens, aging, and prostate health

Due to late onset hypogonadism (LOH), there is an increased usage of testosterone replacement therapy (TRT) in the aging male population. Since prostate is a target organ for androgens and anti-androgenic strategies are used to treat and palliate benign prostate hyperplasia (BPH) and prostate cancer (PC), the prevalence of both increases with age, the possible influence of TRT on prostate health becomes highly relevant. The present review summarizes existing data on the associations between endogenous hormone concentrations and prostate growth and concludes that circulating concentrations of androgens do not appear to be associated with the risks of development of BPH or initiation or progression of PC. The explanation for these findings relates to an apparent insensitivity of prostatic tissue to changes of testosterone concentrations within the physiological range.

Estrogens and Progestogens in Triple Negative Breast Cancer: Do They Harm?

Triple-negative breast cancers (TNBC) occur more frequently in younger women and do not express estrogen receptor (ER) nor progesterone receptor (PR), and are therefore often considered hormone-insensitive. Treatment of premenopausal TNBC patients almost always includes chemotherapy, which may lead to premature ovarian insufficiency (POI) and can severely impact quality of life. Hormone replacement therapy (HRT) is contraindicated for patients with a history of hormone-sensitive breast cancer, but the data on safety for TNBC patients is inconclusive, with a few randomized trials showing increased risk-ratios with wide confidence intervals for recurrence after HRT. Here, we review the literature on alternative pathways from the classical ER/PR. We find that for both estrogens and progestogens, potential alternatives exist for exerting their effects on TNBC, ranging from receptor conversion, to alternative receptors capable of binding estrogens, as well as paracrine pathways, such as RANK/RANKL, which can cause progestogens to indirectly stimulate growth and metastasis of TNBC. Finally, HRT may also influence other hormones, such as androgens, and their effects on TNBCs expressing androgen receptors (AR). Concluding, the assumption that TNBC is completely hormone-insensitive is incorrect. However, the direction of the effects of the alternative pathways is not always clear, and will need to be investigated further.

Determination of Intraprostatic and Intratesticular Androgens

Androgens represent the main hormones responsible for maintaining hormonal balance and function in the prostate and testis. As they are involved in prostate and testicular carcinogenesis, more detailed information of their active concentration at the site of action is required. Since the introduction of the term intracrinology as the local formation of active steroid hormones from inactive precursors of the adrenal gland, mainly dehydroepiandrosterone (DHEA) and DHEA-S, it is evident that blood circulating levels of sex steroid hormones need not reflect their actual concentrations in the tissue. Here, we review and critically evaluate available methods for the analysis of human intraprostatic and intratesticular steroid concentrations. Since analytical approaches have much in common in both tissues, we discuss them together. Preanalytical steps, including various techniques for separation of the analytes, are compared, followed by the end-point measurement. Advantages and disadvantages of chromatography-mass spectrometry (LC-MS, GC-MS), immunoanalytical methods (IA), and hybrid (LC-IA) are discussed. Finally, the clinical information value of the determined steroid hormones is evaluated concerning differentiating between patients with cancer or benign hyperplasia and between patients with different degrees of infertility. Adrenal-derived 11-oxygenated androgens are mentioned as perspective prognostic markers for these purposes.

Proteoglycans in the Pathogenesis of Hormone-Dependent Cancers: Mediators and Effectors

Hormone-dependent cancers exhibit high morbidity and mortality. In spite of advances in therapy, the treatment of hormone-dependent cancers remains an unmet health need. The tumor microenvironment (TME) exhibits unique characteristics that differ among various tumor types. It is composed of cancerous, non-cancerous, stromal, and immune cells that are surrounded and supported by components of the extracellular matrix (ECM). Therefore, the interactions among cancer cells, stromal cells, and components of the ECM determine cancer progression and response to therapy. Proteoglycans (PGs), hybrid molecules consisting of a protein core to which sulfated glycosaminoglycan chains are bound, are significant components of the ECM that are implicated in all phases of tumorigenesis. These molecules, secreted by both the stroma and cancer cells, are crucial signaling mediators that modulate the vital cellular pathways implicated in gene expression, phenotypic versatility, and response to therapy in specific tumor types. A plethora of deregulated signaling pathways contributes to the growth, dissemination, and angiogenesis of hormone-dependent cancers. Specific inputs from the endocrine and immune systems are some of the characteristics of hormone-dependent cancer pathogenesis. Importantly, the mechanisms involved in various aspects of cancer progression are executed in the ECM niche of the TME, and the PG components crucially mediate these processes. Here, we comprehensively discuss the mechanisms through which PGs affect the multifaceted aspects of hormone-dependent cancer development and progression, including cancer metastasis, angiogenesis, immunobiology, autophagy, and response to therapy.

Male hypogonadism: a review

This article contains a systematic review of the main developments that have occurred in the area of male hypogonadism between the publication of the Endocrine Society Guidelines of 2010 and 2018 and after 2018.

Effects of pre- and post-pubertal dihydrotestosterone treatment on penile length in 5α-reductase type 2 deficiency

Steroid 5α-reductase type 2 deficiency (5αRD2) is a congenital disorder of sex development caused by impairment of conversion from testosterone (T) to 5α-dihydrotestosterone (DHT). DHT deficiency leads to various degrees of undervirilized external genitalia including micropenis, primarily correlated with mutations of the SRD5A2 gene that encodes 5α-reductase type 2. Four Japanese boys with isolated micropenis were diagnosed as 5αRD2 by elevated ratios of serum T/DHT, and decreased ratios of urinary 5α/5β-reduced steroid metabolites. Genetic analyses for SRD5A2 identified that the four patients shared a hypomorphic mutation R227Q that has a residual activity related to the mild-form of 5αRD2. For prepubertal micropenis, DHT was transdermally applied to the four patients at the ages of 4-11 year, increasing a median of stretched penile lengths (SPLs) from 2.6 cm (-2.5 SD) to 4.4 cm (-0.2 SD). Nevertheless, the post-pubertal penile growth was apparently retarded, despite normal levels of T secreted from well-developed testes. The second course of DHT treatment underwent at ages of 12-18 year, but unable to normalize SPLs at a range of 6.0 to 7.0 cm (-3.4 to -2.4 SD). The prostate volumes of two patients were variable at 8.1 and 21 cm³, and a sperm cell count of one patient was normal as young adult. DHT treatment contributes to development of the penis and prostate, which are favorable for the potential fertility of 5αRD2 adults. Meanwhile, the retarded penile growth and a risk of prostate overgrowth may complicate the post-pubertal management with DHT for 5αRD2 males.

Durable Response of Enzalutamide-resistant Prostate Cancer to Supraphysiological Testosterone Is Associated with a Multifaceted Growth Suppression and Impaired DNA Damage Response Transcriptomic Program in Patient-derived Xenografts

BACKGROUND

Androgen deprivation therapy improves the survival of castration-resistant prostate cancer (CRPC) patients, yet ultimately fails with debilitating side effects. Supraphysiological testosterone (SPT)-based therapy produces clinical responses with improved quality of life in a subset of patients. Currently, no information defines a durable response to SPT.

OBJECTIVE

To identify key molecular phenotypes underlying SPT response to improve patient selection and guide combination treatment to achieve a durable response.

DESIGN, SETTING, AND PARTICIPANTS

A patient-derived xenograft (PDX) preclinical trial was performed with 13 CRPC PDXs to identify molecular features associated with SPT response. Comprehensive intratumoral androgen, tumor growth, and integrated transcriptomic and protein analyses were performed in three PDXs resistant to the newer androgen receptor (AR) pathway inhibitor enzalutamide (ENZ) to define SPT response and resistance.

INTERVENTION

Testosterone cypionate.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

SPT efficacy was evaluated by PDX growth, prostate-specific antigen (PSA) change, and survival. Intratumoral androgens were analyzed using mass spectrometry. Global transcriptome analysis was performed using RNA sequencing, and confirmed by quantitative real-time polymerase chain reaction and immunohistochemistry. Log-rank and Mann-Whitney tests were used for survival and molecular analyses, respectively.

RESULTS AND LIMITATIONS

A durable SPT responder was identified, presenting robust repressions of ARv7 and E2F transcriptional outputs, and a DNA damage response (DDR) transcriptomic program that were altogether restored upon SPT resistance in the transient responder. ENZ rechallenge of SPT-relapsed PDXs resulted in PSA decreases but tumor progression.

CONCLUSIONS

SPT produces a durable response in AR-pathway inhibitor ENZ CRPC that is associated with sustained suppression of ARv7 and E2F transcriptional outputs, and the DDR transcriptome, highlighting the potential of combination treatments that maintain suppression of these programs to drive a durable response to SPT.

PATIENT SUMMARY

Patients with ENZ-resistant prostate cancer have very limited treatment options. Supraphysiological testosterone presents a prominent option for improved quality of life and a potential durable response in patients with sustained suppression on ARv7/E2F transcriptional outputs and DNA repair program.

Role of Estrogen in Androgen-Induced Prostate Carcinogenesis in NBL Rats

Androgens are thought to cause prostate cancer, but the underlying mechanisms are unclear. Data from animal studies suggest that for androgens to cause prostate cancer, they must be aromatized to estrogen and act in concert with estrogen metabolites. We tested the hypothesis that androgen-receptor and estrogen receptor-mediated effects of androgen and estrogen are necessary, as well as genotoxicity of estrogen metabolites. NBL rats were treated with androgenic and estrogenic compounds for 16-75 weeks through slow-release silastic implants or pellets. Testosterone alone induced cancer in the prostate of 37% of rats. 5α-Dihydrotestosterone, which cannot be converted to estradiol or testosterone, did not cause a significant prostate cancer incidence (4%). Addition of estradiol to 5α-dihydrotestosterone treatment did not markedly enhance prostate cancer incidence (14%), unlike adding estradiol to testosterone treatment which induced a 100% tumor incidence. Testosterone plus estradiol treatment induced a DNA adduct detectable by ³²P-postlabeling, oxidative DNA damage (8-hydroxyguanosine), and lipid peroxidation at the site within the prostate where this treatment causes cancers, preceding later cancer formation. The non-estrogenic 4-hydroxy metabolite of estradiol, when combined with testosterone, induced prostatic dysplasia within 16 weeks and, after long-term treatment, a very low incidence of prostate cancer (21%). When an estrogen that cannot be hydroxylated (2-fluoroestradiol) was added to this combined treatment with testosterone and 4-hydroxyestradiol, dysplasia frequency after 16 weeks was doubled. These results strongly support the hypothesis, but additional definitive studies are needed which may identify new targets to interfere with these mechanisms that are clinically feasible in humans.

Dihydrotestosterone and cancer risk

PURPOSE OF REVIEW

Androgens have been implicated in prostate growth; however, the role of androgens in prostate cancer development is not clear. Furthermore, studies suggest a role for androgens in female-hormone-dependent cancers and common nonhormone dependent cancers. This study aims to review key studies and more recent studies of dihydrotestosterone (DHT) and cancer risk.

RECENT FINDINGS

Epidemiological studies are reassuring as they have not associated endogenous androgens with prostate cancer risk. Intraprostatic regulation of DHT is becoming recognized as an important area of research to clarify the role of DHT in prostate cancer development. In females, further understanding of intracrine regulation of sex hormones and interactions between androgens and estrogens in influencing breast and endometrial cancer risk are required. Studies show a signal for DHT in modulating lung and colorectal cancer growth; however, research in this area is relatively scarce and further studies are required to clarify these associations.

SUMMARY

Although concerns of prostate cancer risk remain, there is also potential for androgens to modulate the growth and development of other common cancers. Further research is required as this may have clinical implications.

Sex steroids in the tumor microenvironment and prostate cancer progression

Prostate cancer is uniquely dependent on androgens. Despite years of research on the relationship between androgens and prostate cancer, many questions remain as to the biological effects of androgens and other sex steroids during prostate cancer progression. This article reviews the clinical and basic research on the influence of sex steroids such as androgens, estrogens and progesterone within the prostate tumor microenvironment on the progression of prostate cancer. We review clinical studies to date evaluating serum sex steroids as prognostic biomarkers and discuss their respective biological effects within the prostate tumor microenvironment. We also review the link between genomic alterations and sex steroid levels within prostate tumors. Finally, we highlight the links between sex steroid levels and the function of the immune system within the tumor microenvironment. As the context of treatment of lethal prostate cancer evolves over time, an understanding of this underlying biology remains central to developing optimal treatment approaches.

Testosterone Rescues the De-Differentiation of Smooth Muscle Cells Through Serum Response Factor/Myocardin

Prostatic smooth muscle cells (pSMCs) differentiation is a key factor for prostatic homeostasis, with androgens exerting multiple effects on these cells. Here, we demonstrated that the myodifferentiator complex Srf/Myocd is up-regulated by testosterone in a dose-dependent manner in primary cultures of rat pSMCs, which was associated to the increase in Acta2, Cnn1, and Lmod1 expressions. Blocking Srf or Myocd by siRNAs inhibited the myodifferentiator effect of testosterone. While LPS led to a dedifferentiated phenotype in pSMCs, characterized by down-regulation of Srf/Myocd and smooth muscle cell (SMC)-restricted genes, endotoxin treatment on Myocd-overexpressing cells did not result in phenotypic alterations. Testosterone at a physiological dose was able to restore the muscular phenotype by normalizing Srf/Myocd expression in inflammation-induced dedifferentiated pSMCs. Moreover, the androgen reestablished the proliferation rate and IL-6 secretion increased by LPS. These results provide novel evidence regarding the myodifferentiating role of testosterone on SMCs by modulating Srf/Myocd. Thus, androgens preserve prostatic SMC phenotype, which is essential to maintain the normal structure and function of the prostate. J. Cell. Physiol. 232: 2806-2817, 2017. © 2016 Wiley Periodicals, Inc.

Androgen Signaling in Prostate Cancer

The androgen-signaling axis plays a pivotal role in the pathogenesis of prostate cancer. Since the landmark discovery by Huggins and Hodges, gonadal depletion of androgens has remained a mainstay of therapy for advanced disease. However, progression to castration-resistant prostate cancer (CRPC) typically follows and is largely the result of restored androgen signaling. Efforts to understand the mechanisms behind CRPC have revealed new insights into dysregulated androgen signaling and intratumoral androgen synthesis, which has ultimately led to the development of several novel androgen receptor (AR)-directed therapies for CRPC. However, emergence of resistance to these newer agents has also galvanized new directions in investigations of prereceptor and postreceptor AR regulation. Here, we review our current understanding of AR signaling as it pertains to the biology and natural history of prostate cancer.

Testosterone Replacement in a Man with Intermediate-risk Prostate Cancer

In brief, a hypogonadal man with successfully treated localized prostate cancer deserves testosterone therapy (TTh) regardless of grade. The evidence is not conclusive but compelling. The story is different for those with intermediate-risk disease who, for a variety of reasons, need TTh but cannot or elect not to have treatment of their primary malignancy, but still desire androgen supplementation.

Taking the first steps in establishing recommendations for testosterone monitoring in men with prostate cancer on androgen-deprivation therapy

The paper by Shayegan et al in this issue of CUAJ represents an important initial step in establishing recommendations for hormonal monitoring in men with prostate cancer on androgen-deprivation therapy (ADT). As with most subjects related to the actions of testosterone, the survey adds to the controversies, but also opens the opportunity to explore several of the concerns relevant to the hormonal management of prostate cancer.

Dihydrotestosterone: Biochemistry, Physiology, and Clinical Implications of Elevated Blood Levels

Benefits associated with lowered serum DHT levels after 5α-reductase inhibitor (5AR-I) therapy in men have contributed to a misconception that circulating DHT levels are an important stimulus for androgenic action in target tissues (e.g., prostate). Yet evidence from clinical studies indicates that intracellular concentrations of androgens (particularly in androgen-sensitive tissues) are essentially independent of circulating levels. To assess the clinical significance of modest elevations in serum DHT and the DHT/testosterone (T) ratio observed in response to common T replacement therapy, a comprehensive review of the published literature was performed to identify relevant data. Although the primary focus of this review is about DHT in men, we also provide a brief overview of DHT in women. The available published data are limited by the lack of large, well-controlled studies of long duration that are sufficiently powered to expose subtle safety signals. Nonetheless, the preponderance of available clinical data indicates that modest elevations in circulating levels of DHT in response to androgen therapy should not be of concern in clinical practice. Elevated DHT has not been associated with increased risk of prostate disease (e.g., cancer or benign hyperplasia) nor does it appear to have any systemic effects on cardiovascular disease safety parameters (including increased risk of polycythemia) beyond those commonly observed with available T preparations. Well-controlled, long-term studies of transdermal DHT preparations have failed to identify safety signals unique to markedly elevated circulating DHT concentrations or signals materially different from T.

Treatment of Hypogonadism: Current and Future Therapies

The treatment of hypogonadism in men is of great interest to both patients and providers. There are a number of testosterone formulations currently available and several additional formulations under development. In addition, there are some lesser-used alternative therapies for the management of male hypogonadism, which may have advantages for certain patient groups. The future of hypogonadism therapy may lie in the development of selective androgen receptor modulators that allow the benefits of androgens whilst minimizing unwanted side effects.

Testosterone replacement therapy and voiding dysfunction

Testosterone replacement therapy (TRT) represents an increasing popular treatment option for men with late-onset hypogonadism (LOH). Because of unsubstantiated beliefs of testosterone’s effect on the prostate, the FDA has recently placed a warning on testosterone products, stating that TRT may worsen benign prostatic hyperplasia (BPH). Within this review article we have demonstrated the current understanding of the physiology of testosterone and its relationship with prostatic and lower urinary tract physiology. The current evidence suggests that not only does TRT not worsen lower urinary tract symptoms (LUTS), but that hypogonadism itself is an important risk factor for LUTS/BPH.

Sex Hormone Decline and Amyloid β Synthesis, Transport and Clearance in the Brain

Sex hormones (SH) are essential regulators of the central nervous system. The decline in SH levels along with ageing may contribute to compromised neuroprotection and set the grounds for neurodegeneration and cognitive impairments. In Alzheimer's disease, besides other pathological features, there is an imbalance between amyloid β (Aβ) production and clearance, leading to its accumulation in the brain of older subjects. Aβ accumulation is a primary cause for brain inflammation and degeneration, as well as concomitant cognitive decline. There is mounting evidence that SH modulate Aβ production, transport and clearance. Importantly, SH regulate most of the molecules involved in the amyloidogenic pathway, their transport across brain barriers for elimination, and their degradation in the brain interstitial fluid. This review brings together data on the regulation of Aβ production, metabolism, degradation and clearance by SH.

Integrated Analysis of Multiple Biomarkers from Circulating Tumor Cells Enabled by Exclusion-Based Analyte Isolation

PURPOSE

There is a critical clinical need for new predictive and pharmacodynamic biomarkers that evaluate pathway activity in patients treated with targeted therapies. A microscale platform known as VERSA (versatile exclusion-based rare sample analysis) was developed to integrate readouts across protein, mRNA, and DNA in circulating tumor cells (CTC) for a comprehensive analysis of the androgen receptor (AR) signaling pathway.

EXPERIMENTAL DESIGN

Utilizing exclusion-based sample preparation principles, a handheld chip was developed to perform CTC capture, enumeration, quantification, and subcellular localization of proteins and extraction of mRNA and DNA. This technology was validated across integrated endpoints in cell lines and a cohort of patients with castrate-resistant prostate cancer (CRPC) treated with AR-targeted therapies and chemotherapies.

RESULTS

The VERSA was validated in cell lines to analyze AR protein expression, nuclear localization, and gene expression targets. When applied to a cohort of patients, radiographic progression was predicted by the presence of multiple AR splice variants and activity in the canonical AR signaling pathway. AR protein expression and nuclear localization identified phenotypic heterogeneity. Next-generation sequencing with the FoundationOne panel detected copy number changes and point mutations. Longitudinal analysis of CTCs identified acquisition of multiple AR variants during targeted treatments and chemotherapy.

CONCLUSIONS

Complex mechanisms of resistance to AR-targeted therapies, across RNA, DNA, and protein endpoints, exist in patients with CRPC and can be quantified in CTCs. Interrogation of the AR signaling pathway revealed distinct patterns relevant to tumor progression and can serve as pharmacodynamic biomarkers for targeted therapies. Clin Cancer Res; 1-11. ©2016 AACR.

Stable Intraprostatic Dihydrotestosterone in Healthy Medically Castrate Men Treated With Exogenous Testosterone

CONTEXT

Concern exists that T replacement therapy (TRT) might increase the risk of prostate disease. There are limited data regarding the impact of TRT on prostate androgen concentrations.

OBJECTIVE

Determine the dose-dependent effects of exogenous T administration on intraprostatic androgen concentrations.

DESIGN

Twelve-week, double-blinded, randomized, placebo-controlled trial.

SETTING

Academic medical center.

PARTICIPANTS

Sixty-two healthy eugonadal men, aged 25-55 years.

INTERVENTIONS

Subjects were randomly assigned to receive injections of acyline, a GnRH antagonist (used to achieve medical castration), every 2 weeks plus transdermal T gel (1.25 g, 2.5 g, 5.0 g, 10 g, or 15 g daily), or placebo injections and transdermal gel for 12 weeks.

MAIN OUTCOMES

Serum T and dihydrotestosterone (DHT) were measured at baseline and every 2 weeks during treatment. Intraprostatic T and DHT concentrations were assessed from tissue obtained through ultrasound-guided prostate needle biopsies at week 12. Androgens were quantified by liquid chromatography-tandem mass spectrometry.

RESULTS

51 men completed the study and were included in the analysis. There were no significant adverse events. Exogenous T resulted in a dose-dependent increase in serum T and DHT concentrations (190-770 and 60-180 ng/dL, respectively). Although intraprostatic T differed among dose groups (P = .01), intraprostatic DHT was comparable regardless of T dose (P = .11) and was 10- to 20-fold greater than intraprostatic T.

CONCLUSIONS

In healthy, medically castrate men receiving exogenous T, the total intraprostatic androgen concentration (predominantly DHT) remained stable across serum T concentrations within the physiological range. These findings further our knowledge of the relationship between serum and intraprostatic androgens and suggest that physiological serum T achieved by TRT is unlikely to alter the prostate hormonal milieu.

Adult-Onset Hypogonadism

In August 2015, an expert colloquium commissioned by the Sexual Medicine Society of North America (SMSNA) convened in Washington, DC, to discuss the common clinical scenario of men who present with low testosterone (T) and associated signs and symptoms accompanied by low or normal gonadotropin levels. This syndrome is not classical primary (testicular failure) or secondary (pituitary or hypothalamic failure) hypogonadism because it may have elements of both presentations. The panel designated this syndrome adult-onset hypogonadism (AOH) because it occurs commonly in middle-age and older men. The SMSNA is a not-for-profit society established in 1994 to promote, encourage, and support the highest standards of practice, research, education, and ethics in the study of human sexual function and dysfunction. The panel consisted of 17 experts in men's health, sexual medicine, urology, endocrinology, and methodology. Participants declared potential conflicts of interest and were SMSNA members and nonmembers. The panel deliberated regarding a diagnostic process to document signs and symptoms of AOH, the rationale for T therapy, and a monitoring protocol for T-treated patients. The evaluation and management of hypogonadal syndromes have been addressed in recent publications (ie, the Endocrine Society, the American Urological Association, and the International Society for Sexual Medicine). The primary purpose of this document was to support health care professionals in the development of a deeper understanding of AOH, particularly in how it differs from classical primary and secondary hypogonadism, and to provide a conceptual framework to guide its diagnosis, treatment, and follow-up.

The current state of male hormonal contraception

World population continues to grow at an unprecedented rate, doubling in a mere 50years to surpass the 7-billion milestone in 2011. This steep population growth exerts enormous pressure on the global environment. Despite the availability of numerous contraceptive choices for women, approximately half of all pregnancies are unintended and at least half of those are unwanted. Such statistics suggest that there is still a gap in contraceptive options for couples, particularly effective reversible contraceptives for men, who have few contraceptive choices. Male hormonal contraception has been an active area of research for almost 50years. The fundamental concept involves the use of exogenous hormones to suppress endogenous production of gonadotropins, testosterone, and downstream spermatogenesis. Testosterone-alone regimens are effective in many men but high dosing requirements and sub-optimal gonadotropin suppression in 10-30% of men limit their use. A number of novel combinations of testosterone and progestins have been shown to be more efficacious but still require further refinement in delivery systems and a clearer understanding of the potential short- and long-term side effects. Recently, synthetic androgens with both androgenic and progestogenic activity have been developed. These agents have the potential to be single-agent male hormonal contraceptives. Early studies of these compounds are encouraging and there is reason for optimism that these may provide safe, reversible, and reliable contraception for men in the near future.

Plk1 inhibition enhances the efficacy of androgen signaling blockade in castration-resistant prostate cancer

Prostate cancer is thought to be driven by oxidative stress, lipid metabolism, androgen receptor (AR) signaling, and activation of the PI3K-AKT-mTOR pathway, but it is uncertain how they may become coordinated during progression to castration-resistant disease that remains incurable. The mitotic kinase polo-like kinase 1 (Plk1) is elevated in prostate cancer, where its expression is linked to tumor grade. Notably, Plk1 signaling and lipid metabolism were identified recently as two of the top five most upregulated pathways in a mouse xenograft model of human prostate cancer. Herein, we show that oxidative stress activates both the PI3K-AKT-mTOR pathway and AR signaling in a Plk1-dependent manner in prostate cells. Inhibition of the PI3K-AKT-mTOR pathway prevented oxidative stress-induced activation of AR signaling. Plk1 modulation also affected cholesteryl ester accumulation in prostate cancer via the SREBP pathway. Finally, Plk1 inhibition enhanced cellular responses to androgen signaling inhibitors (ASI) and overcame ASI resistance in both cultured prostate cancer cells and patient-derived tumor xenografts. Given that activation of AR signaling and the PI3K-AKT-mTOR pathway is sufficient to elevate SREBP-dependent expression of key lipid biosynthesis enzymes in castration-resistant prostate cancer (CRPC), our findings argued that Plk1 activation was responsible for coordinating and driving these processes to promote and sustain the development of this advanced stage of disease. Overall, our results offer a strong mechanistic rationale to evaluate Plk1 inhibitors in combination drug trials to enhance the efficacy of ASIs in CRPC.

Intense androgen-deprivation therapy with abiraterone acetate plus leuprolide acetate in patients with localized high-risk prostate cancer: results of a randomized phase II neoadjuvant study

PURPOSE

Cure rates for localized high-risk prostate cancers (PCa) and some intermediate-risk PCa are frequently suboptimal with local therapy. Outcomes are improved by concomitant androgen-deprivation therapy (ADT) with radiation therapy, but not by concomitant ADT with surgery. Luteinizing hormone-releasing hormone agonist (LHRHa; leuprolide acetate) does not reduce serum androgens as effectively as abiraterone acetate (AA), a prodrug of abiraterone, a CYP17 inhibitor that lowers serum testosterone (< 1 ng/dL) and improves survival in metastatic PCa. The possibility that greater androgen suppression in patients with localized high-risk PCa will result in improved clinical outcomes makes paramount the reassessment of neoadjuvant ADT with more robust androgen suppression.

PATIENTS AND METHODS

A neoadjuvant randomized phase II trial of LHRHa with AA was conducted in patients with localized high-risk PCa (N = 58). For the first 12 weeks, patients were randomly assigned to LHRHa versus LHRHa plus AA. After a research prostate biopsy, all patients received 12 additional weeks of LHRHa plus AA followed by prostatectomy.

RESULTS

The levels of intraprostatic androgens from 12-week prostate biopsies, including the primary end point (dihydrotestosterone/testosterone), were significantly lower (dehydroepiandrosterone, Δ(4)-androstene-3,17-dione, dihydrotestosterone, all P < .001; testosterone, P < .05) with LHRHa plus AA compared with LHRHa alone. Prostatectomy pathologic staging demonstrated a low incidence of complete responses and minimal residual disease, with residual T3- or lymph node-positive disease in the majority.

CONCLUSION

LHRHa plus AA treatment suppresses tissue androgens more effectively than LHRHa alone. Intensive intratumoral androgen suppression with LHRHa plus AA before prostatectomy for localized high-risk PCa may reduce tumor burden.

An update on male hypogonadism therapy

INTRODUCTION

Men who have symptoms associated with persistently low serum total testosterone level should be assessed for testosterone replacement therapy.

AREAS COVERED

Acute and chronic illnesses are associated with low serum testosterone and these should be recognized and treated. Once the diagnosis of male hypogonadism is made, the benefits of testosterone treatment usually outweigh the risks. Without contraindications, the patient should be offered testosterone replacement therapy. The options of testosterone delivery systems (injections, transdermal patches/gels, buccal tablets, capsules and implants) have increased in the last decade. Testosterone improves symptoms and signs of hypogonadism such as sexual function and energy, increases bone density and lean mass and decreases visceral adiposity. In men who desire fertility and who have secondary hypogonadism, testosterone can be withdrawn and the patients can be placed on gonadotropins. New modified designer androgens and selective androgen receptor modulators have been in preclinical and clinical trials for some time. None of these have been assessed for the treatment of male hypogonadism.

EXPERT OPINION

Despite the lack of prospective long-term data from randomized, controlled clinical trials of testosterone treatment on prostate health and cardiovascular disease risk, the available evidence suggests that testosterone therapy should be offered to symptomatic hypogonadal men.

Androgens and prostate disease

A growing body of literature has established the anabolic benefi ts of testosterone (T) therapy in hypogonadal men. However, there remains a paucity of data regarding the risks of exogenous androgen use in older men and the potential for adverse effects on the prostate gland. Whether T therapy in older, hypogonadal men might worsen lower urinary tract symptoms or exacerbate, unmask, or even incite prostate cancer development has tempered enthusiasm for T therapy, while known prostatic disease has served as a relative contraindication to T therapy. Androgens are necessary for the development and maintenance of the prostate gland. However, epidemiologic studies do not consistently fi nd a positive relationship between endogenous serum androgen concentrations and the risk of prostate disease. Recent data demonstrate that 5α-reductase inhibitors decrease the risk of low-grade prostate cancer, suggesting that modifying androgen metabolism may have beneficial effects on prostate health, yet similar reductions in high-grade disease have not been observed, thereby questioning the true clinical benefits of these agents for chemoprevention. Knowing how to best investigate the relationship between androgens and the development of prostate disease given the lack of large, randomized trials is difficult. Accumulating data challenges the assumption that alterations in serum androgens have parallel effects within the prostate hormonal environment or change androgen-regulated processes within the gland. Long-term intervention studies are needed to truly ascertain the effects of androgen manipulation on prostate tissue and disease risk. However, available data do not support the notion that restoring serum androgens to normal physiologic ranges drives prostate disease.

Effect of finasteride on serum levels of androstenedione, testosterone and their 5α-reduced metabolites in men at risk for prostate cancer

Studies show that treatment of men with 5α-reductase inhibitors such as finasteride is effective for the primary prevention of prostate cancer. Although it is known that finasteride treatment suppresses serum levels of dihydrotestosterone (DHT) and its distal metabolite, 5α-androstane-3α,17β-diol glucuronide (3α-diol G), and increases serum testosterone (T) levels, little is known about its effect on other precursors and metabolites of DHT, as well as on the relationship of these androgens to prostate specific antigen (PSA), a marker of prostatic intraepithelial neoplasia. The present study provides new data on the effect of finasteride on precursors and metabolites of DHT. Fifty-three men, ages 57-79 years, with elevated PSA levels (>4ng/ml), were randomized to treatment with finasteride (5mg/day) or observation (controls) for 12 months. Blood samples were obtained at baseline, 1, 3, 6 and 12 months for measurement of PSA, androstenedione (A), T, DHT, 3α-diol G, androsterone glucuronide (ADT G) and DHT sulfate (DHT S) in serum by validated, highly specific radioimmunoassays. Statistical analysis was carried out using mixed model ANOVA and t-tests. In the control group, PSA and androgen levels were unchanged throughout the 12 months of treatment. In the finasteride group, PSA, DHT, DHT S, 3α-diol G and ADT G decreased from baseline to 1 month by 23.2%, 78.7%, 71.0%, 75.7% and 43.0%, respectively. The change in PSA decreased further to 46.1% and 55.1% at 3 and 12 months of treatment, respectively, whereas the decrease in androgens observed at 1 month did not change by more than 6.9% for DHT, DHT S and 3α-diol G in the subsequent months of sampling. However, the decline in ADT G was only 22.2% at month 3, and remained essentially at this level after that time. In contrast, T and A increased significantly from baseline, and the increase in A of approximately 34.5% was about 1.9 times the increase in T (approximately 18.3%). The present data suggest that either 3α-diol G or DHT S may serve as a potential diagnostic marker of intraprostatic 5α-reductase activity during treatment of patients with 5α-reductase inhibitors.

Androgens and prostate cancer; pathogenesis and deprivation therapy

Although androgen receptor signaling is critical for prostate cancer growth and survival, evidence supporting a favorable risk-benefit ratio of androgen deprivation therapy (ADT) is currently limited to men with high-risk or metastatic disease. This is in part because ADT has been associated with a number of constitutional and somatic side effects, consistent with the widespread tissue expression of sex steroid receptors. ADT is the most common contemporary cause of severe hypogonadism, and men receiving this therapy represent a unique model of severe sex steroid deficiency with a defined time of onset. This review will present an update on the role of ADT in the treatment of prostate cancer, will summarize recent evidence regarding ADT-associated adverse effects with particular emphasis on cardiometabolic and musculoskeletal health, and will provide recommendations for further research.

Androgen receptor promotes ligand-independent prostate cancer progression through c-Myc upregulation

The androgen receptor (AR) is the principal therapeutic target in prostate cancer. For the past 70 years, androgen deprivation therapy (ADT) has been the major therapeutic focus. However, some patients do not benefit, and those tumors that do initially respond to ADT eventually progress. One recently described mechanism of such an effect is growth and survival-promoting effects of the AR that are exerted independently of the AR ligands, testosterone and dihydrotestosterone. However, specific ligand-independent AR target genes that account for this effect were not well characterized. We show here that c-Myc, which is a key mediator of ligand-independent prostate cancer growth, is a key ligand-independent AR target gene. Using microarray analysis, we found that c-Myc and AR expression levels strongly correlated with each other in tumors from patients with castration-resistant prostate cancer (CRPC) progressing despite ADT. We confirmed that AR directly regulates c-Myc transcription in a ligand-independent manner, that AR and c-Myc suppression reduces ligand-independent prostate cancer cell growth, and that ectopic expression of c-Myc attenuates the anti-growth effects of AR suppression. Importantly, treatment with the bromodomain inhibitor JQ1 suppressed c-Myc function and suppressed ligand-independent prostate cancer cell survival. Our results define a new link between two critical proteins in prostate cancer – AR and c-Myc – and demonstrate the potential of AR and c-Myc-directed therapies to improve prostate cancer control.

Testosterone replacement therapy and prostate health

There is an emerging evolution in the understanding of the relationship between the prostate and testosterone. It has long been generally believed that with testosterone replacement therapy (TRT), increasing serum testosterone levels led to prostatic growth and worsening of voiding dysfunction and associated complications. A new theory, the Saturation Model of Testosterone and its effect on the Prostate has gained attention. This theory suggests that the prostate's response to increasing levels of serum testosterone reaches a limit beyond which there is minimal effect. This model predicts that testosterone replacement therapy occurs above this saturation point, and replacing testosterone to eugonadal levels should not worsen prostate related benign disease. We evaluated the recent published data, with an emphasis on clinical studies done within the last 3 years, for the effects of testosterone supplementation on benign prostatic disease.

PPP2R2C loss promotes castration-resistance and is associated with increased prostate cancer-specific mortality

Metastatic prostate cancers generally rely on androgen receptor (AR) signaling for growth and survival, even following systemic androgen-deprivation therapy (ADT). However, recent evidence suggests that some advanced prostate cancers escape ADT by using signaling programs and growth factors that bypass canonical AR ligand-mediated mechanisms. We used an in vitro high-throughput RNA interference (RNAi) screen to identify pathways in androgen-dependent prostate cancer cell lines whose loss-of-function promotes androgen ligand-independent growth. We identified 40 genes where knockdown promoted proliferation of both LNCaP and VCaP prostate cancer cells in the absence of androgen. Of these, 14 were downregulated in primary and metastatic prostate cancer, including two subunits of the protein phosphatase 2 (PP2A) holoenzyme complex: PPP2R1A, a structural subunit with known tumor-suppressor properties in several tumor types; and PPP2R2C, a PP2A substrate-binding regulatory subunit that has not been previously identified as a tumor suppressor. We show that loss of PPP2R2C promotes androgen ligand depletion-resistant prostate cancer growth without altering AR expression or canonical AR-regulated gene expression. Furthermore, cell proliferation induced by PPP2R2C loss was not inhibited by the AR antagonist MDV3100, indicating that PPP2R2C loss may promote growth independently of known AR-mediated transcriptional programs. Immunohistochemical analysis of PPP2R2C protein levels in primary prostate tumors determined that low PPP2R2C expression significantly associated with an increased likelihood of cancer recurrence and cancer-specific mortality. These findings provide insights into mechanisms by which prostate cancers resist AR-pathway suppression and support inhibiting PPP2R2C complexes or the growth pathway(s) activated by PPP2R2C as a therapeutic strategy.

Benefits and Consequences of Testosterone Replacement Therapy: A Review

Late onset hypogonadism (LOH) is an issue of increasing concern. Studies have shown the importance of testosterone in the maintenance of homeostasis, especially with respect to bone health, sexual function, diabetes, cardiovascular risk, mental health and cognition. Much of the dysfunction in hypogonadism can be reversed or improved with testosterone replacement therapy (TRT). Physicians worry about the possible consequences of TRT, especially regarding the prostate. By reviewing the literature, we have found there are significant benefits to TRT, and fears of adverse effects on the prostate are largely unfounded, though there is a great need for larger studies with longer periods of follow-up, especially to evaluate adverse events.

Low systemic testosterone levels induce androgen maintenance in benign rat prostate tissue

Prostate cancer (PC) is both an age- and an androgen-dependent disease. Paradoxically, systemic levels of androgens decline with age as the risk of PC rises. While there is no correlation between systemic androgen levels and the risk of PC, systemic androgen levels do not reflect the levels of androgens in prostate tissue. In metastatic PC, changes in the androgen biosynthesis pathway during hormone therapy result in increased levels of androgens in cancer tissue and contribute to continued androgen receptor (AR) signaling. It is possible that similar changes occur in normal prostate tissue as androgen levels decline with age and that this contributes to tumorigenesis. In the present study, we sought to determine whether the rat prostate is able to maintain functional levels of androgens despite low serum testosterone levels. Rats were castrated and implanted with capsules to achieve castrate, normal, sub-physiological, and supra-physiological levels of testosterone. After 6 weeks of treatment, LC-MS/MS was used to quantify the levels of testosterone and dihydrotestosterone (DHT) in the serum and prostate tissue. Quantitative RT-PCR was used to quantify the expression of genes involved in the androgen/AR signaling axis. Despite significantly different levels of testosterone and DHT being present in the serum, testosterone and DHT concentrations in prostate tissue from different testosterone-treatment groups were very similar. Furthermore, the expression of androgen-regulated genes in the prostate was similar among all the testosterone-treatment groups, demonstrating that the rat prostate can maintain a functional level of androgens despite low serum testosterone levels. Low-testosterone treatment resulted in significant alterations in the expression of androgen biosynthesis genes, which may be related to maintaining functional androgen levels.

Androgens, diabetes and prostate cancer

Metabolic disorders such as diabetes, obesity and the metabolic syndrome have been shown to modulate prostate cancer (PCa) risk and aggressiveness in population-based and experimental studies. While associations between these conditions are modest and complex, two consistent findings have emerged. First, there is observational evidence that obesity and associated insulin excess are linked to increased PCa aggressiveness and worse outcomes. Secondly and somewhat paradoxically, long-standing diabetes may be protective against PCa development. This apparent paradox may be due to the fact that long-standing diabetes is associated with insulin depletion and decreased IGF1 signalling. Men with obesity or diabetes have moderate reductions in their androgen levels. The interconnectedness of metabolic and androgen status complicates the dissection of the individual roles of these factors in PCa development and progression. Metabolic factors and androgens may promote prostate carcinogenesis via multiple mechanisms including inflammation, adipokine action, fatty acid metabolism and IGF signalling. Moreover, androgen deprivation, given to men with PCa, has adverse metabolic consequences that need to be taken into account when estimating the risk benefit ratio of this therapy. In this review, we will discuss the current epidemiological and mechanistic evidence regarding the interactions between metabolic conditions, sex steroids and PCa risk and management.

Impact of male hormonal contraception on prostate androgens and androgen action in healthy men: a randomized, controlled trial

CONTEXT

Male hormonal contraception (MHC) combines hypothalamic-pituitary-gonadal axis blockade with exogenous androgen delivery to maintain extragonadal androgen end-organ effects. Concern exists that MHC may adversely impact prostate health.

OBJECTIVE

The objective of the study was to determine the molecular impact of MHC on intraprostatic androgen concentrations and androgen action.

DESIGN

This was a single-blind, randomized, placebo-controlled study.

SETTING

The study was conducted at an academic medical center.

PARTICIPANTS

32 healthy men aged 25-55 yr participated in the study.

INTERVENTION

Interventions included placebo, daily transdermal testosterone (T) (T-gel), T-gel + depomedroxyprogesterone acetate (T+DMPA), or T-gel + dutasteride daily (T+D) for 12 wk, and prostate biopsy during treatment wk 10.

MAIN OUTCOME MEASURES

Serum and prostate androgen concentrations and prostate epithelial-cell gene expression were measured.

RESULTS

Thirty men completed the study. Serum T levels were significantly increased in T-gel and T+D groups compared with baseline (P < 0.05) but were decreased with the addition of DMPA. Intraprostatic androgens were no different from placebo with T-gel treatment. Addition of DMPA to T resulted in 40% lower intraprostatic dihydrotestosterone (DHT) concentration (P = 0.0273 vs. placebo), whereas combining dutasteride with T resulted in a 90% decrease in intraprostatic DHT (P = 0.0012), 11-fold increased intraprostatic T (P = 0.0011), and 7-fold increased intraprostatic androstenedione (P = 0.0011). Significant differences in global or androgen-regulated prostate epithelial-cell gene expression were not observed. Androgen-regulated gene expression correlated with epithelial-cell androgen receptor and prostatic DHT in placebo, T-gel, and T+DMPA arms and with T and androstenedione levels in the T+D arm.

CONCLUSIONS

MHC regimens do not markedly alter gene expression in benign prostate epithelium, suggesting they may not alter risk of prostate disease. Longer-term studies examining the impact of MHC on prostate health are needed.

Pharmacokinetics of modified slow-release oral testosterone over 9 days in normal men with experimental hypogonadism

Oral administration of testosterone has potential use for the treatment of hypogonadism. We have recently demonstrated that a novel formulation of oral testosterone transiently normalized serum testosterone in a single-dose pharmacokinetic study. In this report, we present the steady-state pharmacokinetics of this formulation. Twelve healthy young men were rendered hypogonadal with the gonadotropin-releasing hormone antagonist acyline (300 μg/kg subcutaneously) and administered 300 mg of oral testosterone 3 times daily for 9 days. Serum testosterone, dihydrotestosterone (DHT), estradiol, and sex hormone-binding globulin (SHBG) were measured before and 1, 2, 4, 5, 6, 8, 10, 11, 12, 14, 16, and 24 hours on the first and ninth day of dosing. Before testosterone administration, all men had serum testosterone under 75 ng/dL. Over day 1, the 24-hour average (geometric mean [%CV]) serum total testosterone was 378 (45) ng/dL. This decreased to 315 (41) ng/dL after 9 days of continuous treatment (P = .1 compared with day 1). The 24-hour average serum SHBG was 27 (46) nmol/L on day 1 and was significantly reduced to 19 (47) nmol/L by day 9 (P < .01). As a result, the calculated free testosterone values were similar between day 1 and day 9: 8.7 (43) and 8.3 (37) ng/dL, respectively. DHT was in the reference range and estradiol was slightly below on day 9. Oral testosterone (300 mg) dosed 3 times daily normalized serum testosterone in men with experimentally induced hypogonadism after 9 days of dosing and significantly suppressed SHBG. This formulation of oral testosterone may have efficacy for the treatment of testosterone deficiency.

Male hormonal contraception: potential risks and benefits

An effective, safe, reversible, and acceptable method of contraception is an important component of reproductive health and provides the opportunity of shared responsibility for family planning for both partners. Female hormonal contraceptives have been proven to be safe, reversible, available and widely acceptable by different populations. In contrast, male hormonal contraception, despite significant progress showing contraceptive efficacy comparable to female hormonal methods during last three decades, has not yet led to an approved product. Safety of a pharmaceutical product is an appropriate concern but the majority of male hormonal contraceptive clinical trials have not reported significant short term safety concerns. While the absence of serious adverse effects is encouraging, the studies have been designed for efficacy endpoints not long term safety. In this review we summarize potential risks and benefits of putative male hormonal contraceptives on reproductive and non-reproductive organs. While the review covers what we believe will be the likely class of drugs used for male hormonal contraception a true assessment of long term risks and benefits cannot be achieved without an available product.