Physiologic variations of serum testosterone within the normal range do not affect serum prostate-specific antigen

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.

Safety of androgen therapy in men with prostate cancer

Prostate cancer is one of the most frequently diagnosed malignancies in men worldwide and the life expectancy for men with prostate cancer is improving due to advancements in diagnostics and treatment. Male hypogonadism is associated with obesity, diabetes, and other comorbidities and also has been linked with increasing age; the primary therapy modality for this condition is testosterone replacement therapy (TRT). There are concerns that testosterone therapy may cause prostate cancer disease progression. However, contemporary evidence suggests that testosterone replacement therapy may be safe in specific groups of patients with prostate cancer. This chapter will summarise the contemporary literature regarding TRT use in hypogonadal men with prostate cancer, including limitations and future research goals.

Hypogonadism and its treatment among prostate cancer survivors

Adult-onset hypogonadism (AOH) is associated with sexual dysfunction, poor bone mineralization, decreased muscle mass, metabolic syndrome disorder, and cognitive suppression. Historically, testosterone has been contraindicated in men with a history of prostate cancer. However, there has been a modern resurgence in re-evaluating this belief. Not only can testosterone be safely utilized to alleviate AOH symptoms in prostate cancer survivors, it has been also touted as a treatment option for aggressive prostatic cancer. While much work remains in understanding the relationship between testosterone and prostate cancer, those who survive this disease should not be automatically turned away from an opportunity to be treated and restored.

Association between prostate-specific antigen and serum testosterone: A systematic review and meta-analysis

BACKGROUND

Serum testosterone assays are an important tool in the clinical evaluation of a number of endocrine disorders including male hypogonadism. However, serum testosterone has a limited role in real clinical use due to its inaccuracy. We aimed to assess the association between prostate-specific antigen (PSA) and testosterone as well as the effects of various types of testosterone replacement therapy (TRT) for PSA level.

METHODS

Two electronic databases were screened: PubMed (1966 through December 2018) and Cochrane Library (1993 through December 2018). The first strategy compared the overall increase in PSA following testosterone treatment compared with placebo. The second strategy analyzed the overall association between PSA and testosterone among the observational studies.

RESULTS

In the first strategy, 22 articles were included in the final analysis. In the second strategy, 18 studies were included. Testosterone replacement therapy (TRT) showed a significant change in PSA level compared to that in the placebo group (mean difference [MD]: 0.13, 95% CI: 0.01-0.25, P = .04). Compared to placebo, only intramuscular (IM) TRT shows a significant change in PSA level group (MD: 0.16, 95% CI: 0.01-0.30, P = .04), as neither the oral nor topical type showed a significant change in PSA. In the second strategy analysis, there was no overall correlation found between PSA and testosterone (z = 0.04, 95% CI: -0.04 to 0.12, P = .04; r = 0.039). However, in the subgroup of non-BPH (benign prostate hyperplasia), a significant correlation between PSA and testosterone (z = 0.07, 95% CI: 0.01-0.13, P = .009; r = 0.089) was found.

CONCLUSIONS

We found that TRT, particularly IM TRT, significantly changed the PSA level compared with the placebo group. Furthermore, there was a significant correlation between PSA and testosterone in patients with non-BPH. According to these findings, we suggest the possibility of PSA as a surrogate marker of testosterone.

Late-onset hypogonadism: Prostate safety

BACKGROUND

There have always been concerns regarding testosterone replacement therapy and prostate safety because of the central role of testosterone in prostate tissue. Even though there is a body of evidence supporting that the benefits of testosterone replacement therapy outbalance the risks of prostate disease, this matter is still debatable and represents a common concern among testosterone prescribers.

OBJECTIVES

The aim of this article was to review the influence of testosterone on prostate pathophysiology and discuss the potential impact of testosterone replacement therapy on the most common prostate pathologies, including benign prostatic hyperplasia and prostate cancer.

MATERIALS AND METHODS

We have performed an extensive PubMed review of the literature examining the effects of testosterone replacement therapy on the prostate and its most common affections, especially in terms of safety.

RESULTS

Testosterone replacement therapy has been shown to improve components of metabolic syndrome and decrease prostate inflammation, which is related to the worsening of lower urinary tract symptoms (LUTS) in patients with benign prostatic hyperplasia. Studies evaluating the link between testosterone replacement therapy and benign prostatic hyperplasia/LUTS have mostly demonstrated no change in symptom scores and even some benefits. There are a significant number of studies demonstrating the safety of testosterone replacement therapy in individuals with late-onset hypogonadism and a history of prostate cancer. The most recently published guidelines have already acknowledged this fact and do not recommend against T treatment in this population, particularly in non-high-risk disease.

CONCLUSION

Testosterone replacement therapy could be considered for most men with late-onset hypogonadism regardless of their history of prostate disease. However, a discussion about the risks and benefits of testosterone replacement therapy is always advised, especially in men with prostate cancer. Appropriate monitoring is mandatory.

Prostate-Specific Antigen Within the Reference Range, Subclinical Coronary Atherosclerosis, and Cardiovascular Mortality

RATIONALE

Although PSA (prostate-specific antigen)-a tumor marker for prostate cancer-has been reported to be associated with cardiovascular disease (CVD) risk factors, studies on the association of PSA with subclinical and clinical CVD remain limited.

OBJECTIVE

We examined the association of total serum PSA within the reference range with coronary artery calcium (CAC) score and CVD mortality.

METHODS AND RESULTS

A cross-sectional study was performed in 88 203 Korean men who underwent a health checkup exam including cardiac tomography estimation of CAC score. Logistic regression model was used to calculate odds ratios with 95% CIs for prevalent CAC. PSA levels were inversely associated with the presence of CAC. After adjusting for potential confounders, multivariable-adjusted odds ratio (95% CIs) for prevalent CAC comparing PSA quartiles 2, 3, and 4 to the first quartile were 0.96 (0.90-1.01), 0.88 (0.83-0.93), and 0.85 (0.80-0.90), respectively ( P for trend, <0.001). A cohort study was performed in 243 435 Korean men with a mean age of 39.3 years, PSA values of <4.0 ng/mL, and without known CVD or prostate disease who were followed up with for ≤14 years for CVD mortality (median, 7.3 years). CVD deaths were ascertained through linkage to national death records. Hazard ratios and 95% CIs for CVD mortality were estimated using Cox proportional hazards regression analyses. During 1 829 070.1 person-years of follow-up, 336 CVD deaths were identified. After adjustment for potential confounders, multivariable-adjusted hazard ratios (95% CIs) for CVD mortality comparing PSA quartiles 2, 3, and 4 to the lowest quartile were 0.90 (0.66-1.22), 0.79 (0.58-1.08), and 0.69 (0.51-0.93), respectively.

CONCLUSIONS

Serum total PSA levels within the reference range showed an inverse association with subclinical atherosclerosis and CVD mortality in young and middle-aged Korean men, indicating a possible role of PSA as a predictive marker for subclinical and clinical CVD.

Safety of testosterone therapy in men with prostate cancer

Introduction: The use of testosterone therapy (TTh) in men with prostate cancer (PCa) is relatively new, and controversial, due to the longstanding maxim that TTh is contraindicated in men with PCa. Scientific advances have prompted a reevaluation of the potential role for TTh in men with PCa, particularly as TTh has been shown to provide important symptomatic and general health benefits to men with testosterone deficiency (TD), including many men with PCa who may expect to live 30-50 years after diagnosis. Areas covered: This review outlines the historical underpinnings of the historical belief that TTh 'fuels' PCa and the experimental and clinical studies that have radically altered this view, including description of the saturation model. The authors review studies of TTh in men with PCa following radical prostatectomy and radiation therapy, in men on active surveillance, and in men with advanced or metastatic PCa. Expert opinion: TTh provides important symptomatic and overall health benefits for men with PCa who have TD. Although more safety studies are needed, TTh is a reasonable therapeutic option for men with low-risk PCa after surgery or radiation. Data in men on active surveillance are limited, but initial reports are reassuring.

Testosterone Therapy Among Prostate Cancer Survivors

INTRODUCTION

The use of testosterone in men with a history of prostate cancer remains controversial in light of established findings linking androgens to prostate cancer growth. However, hypogonadism significantly affects quality of life and has negative sequelae, and the risks and benefits of testosterone therapy might be worthwhile to consider in all men, even those with a history of high-risk prostate cancer.

AIM

To discuss the effects of testosterone on the prostate and the use of testosterone therapy in hypogonadal men with a history of prostate cancer.

METHODS

Review of the literature examining the effects of testosterone on the prostate and the efficacy and safety of exogenous testosterone in men with a history of prostate cancer.

MAIN OUTCOME MEASURES

Summary of effects of exogenous and endogenous testosterone on prostate tissue in vitro and in vivo, with a focus on effects in men with a history of prostate cancer.

RESULTS

Testosterone therapy ameliorates the symptoms of hypogonadism, decreases the risk for its negative sequelae, and can significantly improve quality of life. Recent studies do not support an increased risk for de novo prostate cancer, progression of the disease, or biochemical recurrence in hypogonadal men with a history of non-high-risk prostate cancer treated with testosterone therapy. Evidence supporting the use of testosterone in the setting of high-risk prostate cancer is less clear.

CONCLUSION

Despite the historical reluctance toward the use of testosterone therapy in men with a history of prostate cancer, modern evidence suggests that testosterone replacement is a safe and effective treatment option for hypogonadal men with non-high-risk prostate cancer. Additional work to definitively demonstrate the efficacy and safety of testosterone therapy in men with prostate cancer is needed, and persistent vigilance and surveillance of treated men remains necessary.

Testosterone Therapy in Men With Prostate Cancer

CONTEXT

The use of testosterone therapy in men with prostate cancer was previously contraindicated, although recent data challenge this axiom. Over the past 2 decades, there has been a dramatic paradigm shift in beliefs, attitude, and treatment of testosterone deficiency in men with prostate cancer.

OBJECTIVE

To summarize and analyze current literature regarding the effect of testosterone replacement in men with prostate cancer.

EVIDENCE ACQUISITION

We conducted a Medline search to identify all publications related to testosterone therapy in both treated and untreated prostate cancer.

EVIDENCE SYNTHESIS

The historical notion that increasing testosterone was responsible for prostate cancer growth was based on elegant yet limited studies from the 1940s and anecdotal case reports. Current evidence reveals that high endogenous androgen levels do not increase the risk of a prostate cancer diagnosis. Similarly, testosterone therapy in men with testosterone deficiency does not appear to increase prostate cancer risk or the likelihood of a more aggressive disease at prostate cancer diagnosis. Androgen receptor saturation (the saturation model) appears to account for this phenomenon. Men who received testosterone therapy after treatment for localized prostate cancer do not appear to suffer higher rates of recurrence or worse outcomes; although studies to date are limited. Early reports of men on active surveillance/watchful waiting treated with testosterone have not identified adverse progression events.

CONCLUSIONS

An improved understanding of the negative effects of testosterone deficiency on health and health-related quality of life-and the ability of testosterone therapy to mitigate these effects-has triggered a re-evaluation of the role testosterone plays in prostate cancer. An important paradigm shift has occurred within the field, in which testosterone therapy may now be regarded as a viable option for selected men with prostate cancer suffering from testosterone deficiency.

PATIENT SUMMARY

In this article, we review and summarize the existing literature surrounding the use of testosterone therapy in men with prostate cancer. Historically, testosterone was contraindicated in men with a history of prostate cancer. We show that this contraindication is unfounded and, with careful monitoring, its use is safe in that regard.

Controversies and Advances With Testosterone Therapy: A 40-Year Perspective

Testosterone therapy (TTh) has become highly controversial. There are important health consequences of testosterone deficiency, and meaningful benefits with treatment. There is level 1 evidence that TTh improves sexual function and desire, body composition, and bone density. Concerns regarding cardiovascular risk were based on two deeply flawed retrospective studies and are contradicted by dozens of studies showing cardiovascular benefits of TTh or higher endogenous testosterone, including placebo-controlled studies in men with known heart disease (angina, heart failure). Prostate cancer should no longer be considered a risk of TTh. Testosterone is neither scourge nor panacea--it is just good medicine.

Testosterone therapy in men with prostate cancer: literature review, clinical experience, and recommendations

For several decades any diagnosis of prostate cancer (PCa) has been considered an absolute contraindication to the use of testosterone (T) therapy in men. Yet this prohibition against T therapy has undergone recent re-examination with refinement of our understanding of the biology of androgens and PCa, and increased appreciation of the benefits of T therapy. A reassuringly low rate of negative outcomes has been reported with T therapy after radical prostatectomy (RP), radiation treatments, and in men on active surveillance. Although the number of these published reports are few and the total number of treated men is low, these experiences do provide a basis for consideration of T therapy in selected men with PCa. For clinicians considering offering this treatment, we recommend first selecting patients with low grade cancers and undetectable prostate-specific antigen following RP. Further research is required to define the safety of T therapy in men with PCa. However, many patients symptomatic from T deficiency are willing to accept the potential risk of PCa progression or recurrence in return for the opportunity to live a fuller and happier life with T therapy.

Effects of Korean Red Ginseng extract on busulfan-induced dysfunction of the male reproductive system

Background

Anticancer agents induce a variety of adverse effects when administered to cancer patients. Busulfan is a known antileukemia agent. When administered for treatment of leukemia in young patients, busulfan could cause damage to the male reproductive system as one of its adverse effects, resulting in sterility.

Methods

We investigated the effects of Korean Red Ginseng extract (KRGE) on busulfan-induced damage and/or dysfunction of the male reproductive system.

Results

We found that administration of busulfan to mice: decreased testis weight; caused testicular histological damage; reduced the total number of sperm, sperm motility, serum testosterone concentration; and eventually, litter size. Preadministration of KRGE partially attenuated various busulfan-induced damages to the male reproductive system. These results indicate that KRGE has a protective effect against busulfan-induced damage to the male reproduction system.

Conclusion

The present study shows a possibility that KRGE could be applied as a useful agent to prevent or protect the male reproductive system from the adverse side effects induced by administration of anticancer agents such as busulfan.

The prevalence and the risk factors of testosterone deficiency in newly diagnosed and previously known type 2 diabetic men

INTRODUCTION

While the epidemiology of testosterone deficiency has been well described in men with previously known type 2 diabetes mellitus (T2DM), it was less reported in those with untreated, newly diagnosed T2DM.

AIM

The aim of this study was to investigate the prevalence and the risk factors of testosterone deficiency of men with newly diagnosed T2DM.

METHODS

The cross-sectional study included 105 men (mean age: 61.2 ± 6.8 years) with previously known T2DM and another 81 (57.8 ± 8.8 years) with newly diagnosed T2DM. All received health checkup and sex hormone measurement at our institute in 2009.

MAIN OUTCOME MEASURES

We calculated the prevalence and explored the risk factors of low total (<300 ng/dL) and free (<6 ng/dL) testosterone in men with newly diagnosed and previously known T2DM.

RESULTS

Men with previously known T2DM were older and had higher diastolic pressure and greater fasting glucose. There was no significant difference in total (358.0 [155.0] ng/dL vs. 363.0 [154.0] ng/dL, P=0.68) and free (7.2 [2.5] ng/dL vs. 7.4 [2.4]ng/dL, P=0.84) testosterone and sex-hormone binding globulin (SHBG) (27.3 [22.3]nmol/L vs. 28.7 [14.9]nmol/L, P=0.46). The prevalence of low total and free testosterone was 28.4% and 21.0%, respectively, in men with newly diagnosed T2DM, and was 26.7% and 19.0% in those with previously known T2DM. In men with previously known T2DM, better glycemic control (HbA1c <7%) was associated with a higher level of total testosterone and a lower risk of low total testosterone. Men with newly diagnosed and previously known T2DM shared similar risk factors of low total testosterone, including high HbA1c (≥ 7%), low SHBG (<20 nmol/L), obesity, hyperuricemia, hypertriglycemia, and metabolic syndrome. Elevated prostate-specific antigen was a protective factor of low total testosterone. However, none of these factors was associated with low free testosterone.

CONCLUSIONS

The prevalence and the risk factors of testosterone deficiency are similar between newly diagnosed and previously known type 2 diabetic men.

Testosterone deficiency and replacement: Myths and realities

Testosterone deficiency, or hypogonadism, is common and may have deleterious effects on men, including decreased overall well-being, reduced sexual function and bone loss. Despite data demonstrating strong links between testosterone deficiency and significant comorbid conditions (including type 2 diabetes and metabolic syndrome as well as the health benefits of testosterone-replacement therapy [TRT]), some physicians are still hesitant to initiate these therapies. Their reluctance is based on a number of prevailing myths associating TRT with adverse prostate health and recent concerns highlighting the possibility of increased cardiovascular risk.

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.

Serum PSA as a predictor of testosterone deficiency

INTRODUCTION

The relationship between serum prostate-specific antigen (PSA) and testosterone (T) levels is still controversial. According to the "saturation hypothesis," a significant relationship is apparent only in the low T range.

AIM

To verify whether, in a large sample of male subjects seeking medical care for sexual dysfunction (SD), PSA might represent a reliable marker of T levels.

METHODS

A consecutive series of 3,156 patients attending our unit for SD was studied. Among them, only subjects without history of prostate disease and with PSA levels<4 ng/mL (N=2,967) were analyzed.

MAIN OUTCOME MEASURES

Several hormonal and biochemical parameters were studied, along with structured interview on erectile dysfunction (SIEDY), ANDROTEST, and PsychoANDROTEST.

RESULTS

Receiver operating characteristic curve analysis for predicting severe hypogonadism (T<8 nmol/L) showed an accuracy of PSA=0.612±0.022 (P<0.0001), with the best sensitivity and specificity at PSA<0.65 ng/mL (65.2% and 55.5%, respectively). In the entire cohort, 254 subjects (8.6%) showed T<8 nmol/L and, among them, more than half (N=141, 4.8%) had PSA<0.65 ng/mL. After adjusting for age, low PSA was associated with hypogonadism-related features (i.e., delayed puberty, lower testis volume) and associated conditions, such as metabolic syndrome (hazard ratio [HR]=1.506 [1.241-1.827]; P<0.0001), type 2 diabetes (HR=2.044 [1.675-2.494]; P<0.0001), and cardiovascular diseases (HR=1.275 [1.006-1.617]; P=0.045). Furthermore, low PSA was associated with impaired sex- and sleep-related erections. The association between low PSA and hypogonadal symptoms and signs as well as with metabolic syndrome was retained even after adjusting for T levels. Sensitivity and positive predictive values of low PSA increased, whereas specificity and negative predictive value decreased as a function of age.

CONCLUSIONS

PSA is a marker of T concentrations and it may represent a new tool in confirming hypogonadism. The determination of PSA levels might give insights not only on the circulating levels of total T but also on its active fractions.

Cistanches herba induces testis cytotoxicity in male mice

We investigated the effects of Cistanches herba (CH) on the male reproductive system in mice, assessing CREM gene expression and spermatogenesis. Our results demonstrate that CH treatment lead to a significant decrease in sperm count dose-dependently, 298.3 ± 48.9 vs. 296.6 ± 102.4 (250 mg/kg), 236.7 ± 75.1 (500 mg/kg), 223.0 ± 48.7 × 10(6) (1000 mg/kg), respectively. Additionally, serum testosterone levels decreased following CH treatment to as low as ~57% compared with the vehicle-treated group. CREM gene expression was also down-regulated following CH treatment and histological examination of the testicular seminiferous tubules showed severe damage on CH treatment. These results suggest that CH induces cytotoxicity in the male reproductive system, through the inhibition of spermatogenesis, testicular damage, and limited hormonal function.

Diagnosis and treatment of sexual dysfunctions in late-onset hypogonadism

Testosterone is the principal androgen in the human male. The decline of testosterone with aging was recognized to be associated with a number of symptoms and signs that reduce the quality of life and that may even have severe, debilitating consequences. Clinically, late-onset hypogonadism (LOH) is diagnosed by use of biochemical and clinical measures. Despite published guidelines and recommendations, however, uncertainty surrounds the profile of clinical symptoms as well as the biochemical threshold of diagnosis. Clinicians should be aware of these shortcomings while adhering to the guidelines. Current treatment methods are centered on restoring testosterone to mid to lower levels of young men with natural testosterone replacements. Although recent studies have highlighted possible additional benefits involving improvement of systemic disorders, the goal of treatment is to improve sexual function, while observing for adverse effects in the prostate. Overall, the problem of LOH in debilitating the quality of life and well-being is real, and by following proper guidelines with attentiveness to the results of treatment trials, testosterone replacement therapy presents a safe and effective treatment option.

Low incidence of new biochemical and clinical hypogonadism following hypofractionated stereotactic body radiation therapy (SBRT) monotherapy for low- to intermediate-risk prostate cancer

Background

The CyberKnife is an appealing delivery system for hypofractionated stereotactic body radiation therapy (SBRT) because of its ability to deliver highly conformal radiation therapy to moving targets. This conformity is achieved via 100s of non-coplanar radiation beams, which could potentially increase transitory testicular irradiation and result in post-therapy hypogonadism. We report on our early experience with CyberKnife SBRT for low- to intermediate-risk prostate cancer patients and assess the rate of inducing biochemical and clinical hypogonadism.

Methods

Twenty-six patients were treated with hypofractionated SBRT to a dose of 36.25 Gy in 5 fractions. All patients had histologically confirmed low- to intermediate-risk prostate adenocarcinoma (clinical stage ≤ T2b, Gleason score ≤ 7, PSA ≤ 20 ng/ml). PSA and total testosterone levels were obtained pre-treatment, 1 month post-treatment and every 3 months thereafter, for 1 year. Biochemical hypogonadism was defined as a total serum testosterone level below 8 nmol/L. Urinary and gastrointestinal toxicity was assessed using Common Toxicity Criteria v3; quality of life was assessed using the American Urological Association Symptom Score, Sexual Health Inventory for Men and Expanded Prostate Cancer Index Composite questionnaires.

Results

All 26 patients completed the treatment with a median 15 months (range, 13-19 months) follow-up. Median pre-treatment PSA was 5.75 ng/ml (range, 2.3-10.3 ng/ml), and a decrease to a median of 0.7 ng/ml (range, 0.2-1.8 ng/ml) was observed by one year post-treatment. The median pre-treatment total serum testosterone level was 13.81 nmol/L (range, 5.55 - 39.87 nmol/L). Post-treatment testosterone levels slowly decreased with the median value at one year follow-up of 10.53 nmol/L, significantly lower than the pre-treatment value (p < 0.013). The median absolute fall was 3.28 nmol/L and the median percent fall was 23.75%. There was no increase in biochemical hypogonadism at one year post-treatment. Average EPIC sexual and hormonal scores were not significantly changed by one year post-treatment.

Conclusions

Hypofractionated SBRT offers the radiobiological benefit of a large fraction size and is well-tolerated by men with low- to intermediate-risk prostate cancer. Early results are encouraging with an excellent biochemical response. The rate of new biochemical and clinical hypogonadism was low one year after treatment.

Prostate-specific antigen levels are associated with arterial stiffness in essential hypertensive patients

INTRODUCTION

Prostate-specific antigen (PSA) has been recently related to cardiovascular system in a multifactorial way. Arterial stiffness is a independent predictor of cardiovascular events and is involved in the pathogenesis of hypertension. The aim of the present study was to investigate whether PSA values, are associated with arterial stiffness indices in patients with essential arterial hypertension.

METHODS

The study comprised 150 consecutive male patients (mean age 60 years) with uncomplicated never-treated essential hypertension. All patients underwent a complete clinical and laboratory evaluation, including measurement of PSA levels. Aortic stiffness and arterial wave reflection assessment was made by using carotid-femoral (PWVc-f) pulse wave velocity and aortic augmentation index corrected for heart rate (AIx75). Patients with prostate cancer or benign prostate hyperplasia (PSA > 4 ng/mL) were excluded from the study.

RESULTS

PSA was positively associated with waist-to-hip ratio (r = 0.235, P = 0.04), PWVc-f (r = 0.426, P < 0.001), AIx75 (r = 0.264, P = 0.001), and high sensitivity C-reactive protein (hsCRP; r = 0.376, P < 0.001). In categorization to PSA quartiles, patients in the higher quartile presented with higher waist-to hip ratio (P = 0.009), PWVc-f (P < 0.00001), AIx75 (P < 0.001) and hsCRP (P < 0.001) values. In multivariate analysis after adjustment for various confounders PSA remained a significant determinant of PWVc-f values (beta [SE] = 0.477 [0.13], R(2) = 0.405, P < 0.001).

CONCLUSION

The present study points towards an association between PSA levels and aortic stiffness in untreated essential hypertensive males. Potential causal relationships between PSA and arterial stiffness remain to be further explored.

Shifting the paradigm of testosterone and prostate cancer: the saturation model and the limits of androgen-dependent growth

CONTEXT

The traditional belief that prostate cancer (PCa) growth is dependent on serum testosterone (T) level has been challenged by recent negative studies in noncastrated men.

OBJECTIVE

To provide an improved framework for understanding the relationship of PCa to serum T level that is consistent with current evidence and is based on established biochemical principles of androgen action within the prostate.

EVIDENCE ACQUISITION

A literature search was performed of publications dating from 1941 to 2008 that addressed experimental and clinical effects of androgens on prostate growth. Review of studies investigating the prostatic effects of manipulation of androgen concentrations in human and animal studies, and in PCa cell lines.

EVIDENCE SYNTHESIS

Prostate growth is exquisitely sensitive to variations in androgen concentrations at very low concentrations, but becomes insensitive to changes in androgen concentrations at higher levels. This pattern is consistent with the observation that androgens exert their prostatic effects primarily via binding to the androgen receptor (AR), and that maximal androgen-AR binding is achieved at serum T concentrations well below the physiologic range. A Saturation Model is proposed that accounts for the seemingly contradictory results in human PCa studies. Changes in serum T concentrations below the point of maximal androgen-AR binding will elicit substantial changes in PCa growth, as seen with castration, or with T administration to previously castrated men. In contrast, once maximal androgen-AR binding is reached the presence of additional androgen produces little further effect.

CONCLUSIONS

The evidence clearly indicates that there is a limit to the ability of androgens to stimulate PCa growth. A Saturation Model based on androgen-AR binding provides a satisfactory conceptual framework to account for the dramatic effects seen with castration as well as the minor impact of T administration in noncastrated men.

Clinical practice experience with testosterone treatment in men with testosterone deficiency syndrome

OBJECTIVE

To report on a clinical practice series of testosterone-replacement therapy (TRT) in men with testosterone deficiency syndrome (TDS), examining clinical efficacy, biochemical parameters and effects on prostate health over a 2-year period.

PATIENTS AND METHODS

A retrospective review of 85 patients with symptoms of TDS and at least a 3-month trial of TRT was performed in this single-centre, clinical practice setting. Three domains of symptomatology were evaluated: libido, erectile function and energy levels. Symptoms were assessed by a combination of patient reporting, physician's assessment and validated symptom assessment scores. Total testosterone (TT), calculated bio-available testosterone (BT) and prostate-specific antigen (PSA) levels were continuously measured and effects on prostate health were examined.

RESULTS

Only 38 (45%) patients in this cohort remained on TRT for >2 years. The most common reason for discontinuing treatment was lack of clinical response but those remaining on TRT had continued improvement in libido, erectile function and energy levels. During treatment, the average TT and calculated BT values significantly increased compared with the baseline values at most of the evaluated time points, with no significant change in average PSA values. In all, 15% of this cohort had some degree of progression of lower urinary tract symptoms. Seven patients had eight 'for-cause' prostate biopsies either during supplementation or at any date after completion, with an only three positive for cancer.

CONCLUSIONS

Only 45% of men on TRT remained on treatment for >2 years in this clinical practice experience of men with TDS. Those remaining showed persistent improvement in their symptoms. The average TT and BT values increased significantly with no significant change in PSA levels.

Serum prostate-specific antigen levels in men with type 2 diabetes

OBJECTIVE

The aims of this study were to examine if serum prostate-specific antigen (PSA) levels are lower in men with type 2 diabetes compared with those in healthy men and to investigate what factors may be associated with serum PSA levels in men with type 2 diabetes.

RESEARCH DESIGN AND METHODS

We compared the serum PSA levels in 224 diabetic men with those in 1,293 healthy men and investigated the relationships between serum PSA levels and various variables.

RESULTS

Except for men aged 40-49 years, serum PSA levels were lower in diabetic men than in healthy men. Multiple regression analysis demonstrated that age, BMI, and presence of diabetes were independent determinants of serum PSA level.

CONCLUSIONS

Serum PSA levels were lower in diabetic men compared with those in healthy men, which is in line with previous reports that patients with type 2 diabetes are at a decreased risk of prostate cancer.

Prostate-specific antigen values in diabetic and nondiabetic US men, 2001-2002

Recent studies have shown that diabetic men have a lower risk of prostate cancer and that this association may be related to time since diagnosis. The authors examined the association between diabetes and prostate-specific antigen (PSA) levels, controlling for potential confounders, in a nationally representative cross-sectional survey of the US population (National Health and Nutrition Examination Survey 2001-2002). Diabetes classification was self-reported, and undiagnosed diabetes was determined with fasting plasma glucose measurements. Controlling for age, men with self-reported diabetes had a 21.6% lower geometric mean PSA level than men without diabetes. The difference increased with years since diagnosis (>10 years: 27.5% lower geometric mean PSA level). Overweight men who had had diabetes for more than 10 years had a predicted geometric mean PSA level 40.8% lower than that of nondiabetic, normal-weight men. These results are consistent with the hypothesis that long-term diabetes is associated with a lower risk of prostate cancer. The mechanism of this association may involve the regulation of PSA by androgens, although the authors are unable to confirm this assertion. Better understanding of the determinants of PSA level is needed to make the distinction between factors affecting the PSA test's accuracy and those altering the risk of prostate cancer.

Androgen receptor CAG repeat length correlates with semen PSA levels in adolescence

BACKGROUND

Androgens exert their action through the androgen receptor (AR). The length of the AR CAG repeat is inversely correlated to receptor function and short CAG length might be a risk factor for development of prostate cancer. Our aim was to investigate whether CAG repeat number might have an impact on prostate function in adolescence.

METHODS

AR genotyping was performed by direct sequencing of leukocyte DNA from 274 military conscripts. All men underwent endocrine evaluation and semen analysis.

RESULTS

PSA in seminal plasma, total sperm count and motility all are inversely correlated with CAG numbers (rho = -0.128, P = 0.038; rho = -0.156, P = 0.010; rho = -0.158, P = 0.011), whereas serum levels of free testosterone (rho = 0.132; P = 0.029) and luteinizing hormone (rho = 0.126; P = 0.037) are positively correlated to CAG length. No correlation between seminal PSA and serum testosterone, neither free nor total, was found.

CONCLUSIONS

In adolescence, AR genotype, but not serum testosterone, is associated with the level of seminal PSA.

Low serum testosterone level predicts worse response to endocrine therapy in Japanese patients with metastatic prostate cancer

Patients with prostate cancer generally respond to androgen withdrawal therapy, but progression to androgen-independence is frequently observed later. To examine whether pretreatment serum androgen status could predict disease progression in metastatic prostate cancer, pretreatment serum testosterone, histological grade, extent of bony metastasis, serum prostate-specific antigen (PSA) response to hormone therapy, and prognosis of the 40 patients with untreated metastatic prostate cancer who received endocrine therapy were evaluated. Although there were no differences in age, pretreatment PSA level, extent of bony disease and histological grade between patients with normal testosterone and those with low testosterone, PSA response after endocrine therapy was better in normal testosterone group. There was a significantly longer interval to disease progression in patients with normal testosterone than in those with low testosterone. The patients with metastatic prostate cancer with low serum testosterone were in the high risk group of worse response to endocrine therapy. Additional therapy might be considered in those patients.

Serum testosterone levels after external beam radiation for clinically localized prostate cancer

PURPOSE

To determine whether serum total testosterone levels change after external beam radiation therapy for localized prostate cancer.

METHODS AND MATERIALS

Eighty-five men with clinically localized prostate cancer (T1-T3, N0/NX, M0) who underwent external beam radiation therapy without androgen ablation had pretreatment and 3-month posttreatment total serum testosterone levels determined by radioimmunoassay. Scattered doses to the testicles were measured with thermoluminescent dosimetry in 10 men.

RESULTS

Pretreatment serum testosterone levels ranged from 185 to 783 ng/dl, with a mean of 400 ng/dl and a median of 390 ng/dl. The coefficient of variation was 30%. Postradiation 3-month testosterone levels ranged from 163 ng/dl to 796 ng/dl, with mean and median values of 356 ng/dl and 327 ng/ml, respectively. The coefficient of variation was 34%. The 3-month value was significantly lower than the pretreatment value (Wilcoxon paired p = 0.0001). The mean absolute fall was 94 ng/dl and the mean percentage fall was 9%. Although the fall in testosterone level was statistically significant, the difference was very small quantitatively. In contrast, serum prostate-specific antigen levels fell dramatically by 3 months after radiation. Testicular scattered doses ranged from 1.84 to 2.42 Gy, with a mean of 2.07 Gy for a prostatic tumor dose of 68 Gy.

CONCLUSIONS

Although significant, the fall in serum testosterone level after radiation for localized prostate cancer was small and likely of no pathophysiologic consequence. It is unlikely that scattered testicular radiation plays any significant role in the genesis of this change in testosterone level, which most likely occurs as a nonspecific stress response.

Serum testosterone--a significant determinant of metastatic relapse for irradiated localized prostate cancer

OBJECTIVES

To determine if the serum total testosterone concentration correlates with the outcome for men irradiated for clinically localized prostate cancer.

METHODS

The outcome-local, nodal, distant metastatic, and biochemical--for 486 men with clinically localized prostate cancer treated by radiation and for whom testosterone levels were available was analyzed. No patient received adjuvant androgen ablation. Patient tumor stages were T1: 129 (27%); T2: 187 (38%); and T3/T4: 170 (35%). Median follow-up was 41 months.

RESULTS

Pretreatment testosterone values ranged from 109 to 1121 ng/dL, with a mean of 417 ng/dL and a median of 398 ng/dL. The distribution of patients according to a four-tier testosterone grouping was testosterone level of 300 ng/dL or less, 108 (22%); testosterone level greater than 300 ng/dL but not more than 400 ng/dL, 141 (29%); testosterone level greater than 400 ng/dL but not more than 500 ng/dL, 123 (25%); and testosterone level greater than 500 ng/dL, 114 (23%). There were statistically significant but trivial correlations between testosterone level and age, T-stage, and acid phosphatase level. There was no correlation between testosterone and prostate-specific antigen (PSA) levels. There was a highly significant correlation between testosterone level and metastatic relapse. Patients with testosterone level greater than 500 ng/dL had a markedly higher 6-year metastatic rate (16%) than those with a testosterone level of 500 ng/dL or less (4%) (P = 0.001). In multivariate analysis, testosterone level was an independent determinant of metastatic relapse, second only to PSA level and of about the same power as T-stage. Gleason grade, although significant, was less so than testosterone level. The correlation of testosterone level to outcome appeared to be specific for metastatic relapse having no relation to local outcome. Likewise, high testosterone levels were not associated with acceleration of postradiation serum PSA kinetics.

CONCLUSIONS

There is a highly significant correlation between pretreatment testosterone level and metastatic relapse in patients with clinically localized prostate cancer treated with radiation. As serum testosterone increases, so too does metastatic relapse. This relationship appears to take a decided turn for the worse at testosterone levels exceeding 500 ng/dL.