Longitudinal evaluation of serum androgen levels in men with and without prostate cancer

Are serum hormones associated with the risk of prostate cancer? Prospective results from the Massachusetts Male Aging Study

OBJECTIVES

To determine whether prediagnostic serum hormones are predictive of prostate cancer risk in a sample of men 40 to 70 years old at baseline.

METHODS

Seventeen serum hormones, including androgens, estrogens, and adrenal and pituitary hormones, were measured at baseline (1987 to 1989) and used to predict incident prostate cancer by follow-up (1995 to 1997) using data from the Massachusetts Male Aging Study, a prospective, population-based random sample.

RESULTS

Seventy men (4%) of 1576 were diagnosed with prostate cancer between the baseline and follow-up periods (approximately 8 years). None of the hormones were associated with prostate cancer risk except for androstanediol glucuronide (AAG), which exhibited a nonlinear, inverse relationship with prostate cancer (P <0.003) when age, body mass index, alcohol use, dihydrotestosterone, and total prostate-specific antigen were controlled for. Men in the second, third, and fourth quartiles of AAG relative to the first were less likely to be diagnosed with prostate cancer, although only the comparison of the second versus the first achieved statistical significance (odds ratio 0.2, 99% confidence interval 0.04 to 0.6). No dose-response relationships were observed.

CONCLUSIONS

The lack of association with most hormones and the nonlinear association with AAG calls into question whether serum hormones collected during midlife are risk factors for prostate cancer.

Effects of transdermal testosterone on bone and muscle in older men with low bioavailable testosterone levels

BACKGROUND

A large proportion of men over 65 years of age have bioavailable testosterone levels below the reference range of young adult men. The impact of this on musculoskeletal health and the potential for improvement in function in this group with testosterone supplementation require investigation.

METHODS

Sixty-seven men (mean age 76 +/- 4 years, range 65--87) with bioavailable testosterone levels below 4.44 nmol/l (lower limit for adult normal range) were randomized to receive transdermal testosterone (two 2.5-mg patches per day) or placebo patches for 1 year. All men received 500 mg supplemental calcium and 400 IU vitamin D. Outcome measures included sex hormones (testosterone, bioavailable testosterone, sex-hormone binding globulin [SHBG], estradiol, and estrone), bone mineral density (BMD; femoral neck, Ward's triangle, trochanter, lumbar spine, and total body), bone turnover markers, lower extremity muscle strength, percent body fat, lean body mass, hemoglobin, hematocrit, prostate symptoms, and prostate specific antigen (PSA) levels.

RESULTS

Twenty-three men (34%) withdrew from the study; 44 men completed the trial. In these men, bioavailable testosterone levels increased from 3.2 +/- 1.2 nmol/l (SD) to 5.6 +/- 3.5 nmol/l (p <.002) at 12 months in the testosterone group, whereas no change occurred in the control group. Although there was no change in estradiol levels in either group, estrone levels increased in the testosterone group (103 +/- 26 pmol/l to 117 +/- 33 pmol/l; p <.017). The testosterone group had a 0.3% gain in femoral neck BMD, whereas the control group lost 1.6% over 12 months (p =.015). No significant changes were seen in markers of bone turnover in either group. Improvements in muscle strength were seen in both groups at 12 months compared with baseline scores. Strength increased 38% (p =.017) in the testosterone group and 27% in the control group (p =.06), with no statistical difference between the groups. In the testosterone group, body fat decreased from 26.3 +/- 5.8% to 24.6 +/- 6.5% (p =.001), and lean body mass increased from 56.2 +/- 5.3 kg to 57.2 +/- 5.1 kg (p =.001), whereas body mass did not change. Men receiving testosterone had an increase in PSA from 2.0 +/- 1.4 microg/l to 2.6 +/- 1.8 microg/l (p =.04), whereas men receiving placebo had an increase in PSA from 1.9 +/- 1.0 microg/l to 2.2 +/- 1.5 microg/l (p =.09). No significant differences between groups were seen in hemoglobin, hematocrit, symptoms or signs of benign prostate hyperplasia, or PSA levels.

CONCLUSIONS

Transdermal testosterone (5 mg/d) prevented bone loss at the femoral neck, decreased body fat, and increased lean body mass in a group of healthy men over age 65 with low bioavailable testosterone levels. In addition, both testosterone and placebo groups demonstrated gains in lower extremity muscle strength, possibly due to the beneficial effects of vitamin D. Testosterone did result in a modest increase in PSA levels but resulted in no change in signs or symptoms of prostate hyperplasia.

Hypogonadism and androgen replacement therapy in elderly men

The decrease in testosterone levels with age is both central (pituitary) and peripheral (testicular) origin. Because serum levels of sex-hormone-binding globulin increase with aging, the decrease in free testosterone is of even greater magnitude. Recent long-term studies of testosterone therapy in hypogonadal elderly men have shown beneficial effects on bone density, body composition, and muscle strength without any substantial adverse effects on lipids and the prostate. Total testosterone level is the test of choice for initial screening of elderly men who present with signs and symptoms of hypogonadism. If the level is below 300 ng/dL, replacement therapy should be initiated. If the level is normal in a symptomatic patient, free or bioavailable testosterone should be determined. The pros and cons of testosterone therapy should be discussed in depth with every patient, and decisions should be made on an individual basis. This review summarizes the trials of testosterone replacement therapy in elderly men and outlines a diagnostic approach to these patients.

High-grade prostate cancer is associated with low serum testosterone levels

BACKGROUND

The aim of this study was to assess whether low serum testosterone levels in men with newly diagnosed prostate cancer have an association to the endocrine status, prostate-specific antigen (PSA) levels, Gleason score, and androgen receptor expression.

METHODS

Besides a full clinical work-up, the following hormones were quantified in men with newly diagnosed prostate cancer by serum analysis: total testosterone, human luteinising hormone (hLH), human follicle stimulating hormone (hFSH), estradiol, and dehydroepiandrostendione (DHEA). In a subgroup of men, androgen receptor expression was determined immunohistochemically.

RESULTS

One hundred and fifty six patients (65.7 +/- 8.5 yrs) with a mean PSA of 29.8 ng/ml (median: 7.4 ng/ml) were analysed. Fifty-two patients (33%) had a partial androgen deficiency (serum testosterone < 3.0 ng/ml). These men had lower hLH (3.3 vs. 5.9 mIU/ml), hFSH (6.2 vs. 8.4 mIU/ml), and estradiol (18.8 vs. 29.1 pg/ml) serum levels. Mean Gleason score was higher (7.4 vs. 6.2) in men with a low serum testosterone, PSA-levels were lower (25.3 vs. 31.9 ng/ml). Mean testosterone levels decreased from 4.1 +/- 1.7 ng/ml in patients with Gleason scores < or = 5 to 2.8 +/- 2.7 ng/ml with Gleason scores > or = 8. Androgen receptor expression was higher in patients with low serum testosterone.

CONCLUSIONS

Patients with high Gleason score prostate cancer have lower testosterone and estradiol serum levels. The fact that gonadotropins were lower in parallel suggests a tumor-mediated suppression of the hypothalamic-pituitary-gonadal hormone axis particularly in men with high Gleason score tumours.

Testosterone in ageing men

A progressive decline in androgen levels is a common finding in men after middle age. The resulting clinical picture may be characterised by alterations in the physical and psychological domains, which have been demonstrated to correlate positively with testosterone serum levels. This clinical picture closely resembles the features of primary or secondary hypogonadism. Testosterone is the more convenient hormone for substitution therapy in classic hypogonadism as well as in age-related hypoandrogenism. Different choices of testosterone preparations are currently available, which are characterised by different routes of administration and by various pharmacokinetic profiles. Two major achievements urgently need to be investigated in the near future: the ability of the new formulations to reach more physiological and sustained hormone levels with the concomitant amelioration of their tolerability and the evidence of long-term prospective studies aimed at demonstrating the benefits and the possible complications of this therapy.

Androgens and aging

This review supports the conclusion that the use of testosterone replacement therapy for the treatment of the symptoms of androgen deficiency in aging males (ADAM) may be appropriate if undertaken with due caution. The best safety data exists for using oral therapy with testosterone undeconoate. Less data exists for the treatment of postmenopausal women with testosterone. Tibolone (an estrogen--prostagen--testosterone) compound, may make the need for testosterone being added to estrogen in women unnecessary. Less data is available to support the use of DHEA or its sulfate or pregnenolone. Further studies are clearly necessary in all these areas. However, it may be tentatively concluded that we are at the dawning of the age of androgens.

Endocrine patterns in patients with benign and malignant prostatic diseases

BACKGROUND

The known importance of the endocrine system, particularly of steroid hormones, for development of the prostate gland and the fact that steroid hormones act as immunmodulators prompted us to compare hypophyseal, adrenal, and gonadal hormones, including cortisol, in patients with benign and malignant prostatic diseases.

METHODS

Patients with newly diagnosed, untreated prostate cancer (PC) (n = 75) and, as a control population, those with untreated lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH) (n = 159) entered this prospective study. In all patients, the following parameters were obtained by serum analysis: prostate-specific antigen (PSA), human luteinizing hormone (hLH), human follicle-stimulating hormone (hFSH), testosterone, estradiol (E2), cortisol, and dehydroepiandrosterone-sulphate (DHEA-S). Serum samples were collected of fasting patients between 7. 30-10.00 AM.

RESULTS

Age was comparable in both groups (PC: 65.6 +/- 7.6 years (mean +/- standard deviation) vs. controls: 64.9 +/- 8. 1 years; P = 0.56). HFSH (PC: 6.6 +/- 3.9 mIU/ml; controls: 8.4 +/- 6.4 mIU/ml; P = 0.04), hLH (PC: 5.3 +/- 4.8mIU/ml; controls: 7.6 +/- 6.2 mIU/ml; P = 0.009), and estradiol (PC: 25.8 +/- 12.7 pg/ml; controls: 32.6 +/- 12.6 pg/ml; P = 0.0003) were significantly lower in PC patients than controls. Cortisol (PC: 16.7 +/- 4.2 microg/dl; controls: 13.5 +/- 4.3 microg/dl; P < 0.0001) was significantly higher in cases. The difference for cortisol and estradiol concentrations between PC patients and controls held true in all life-decades. Serum concentrations for DHEA-S and testosterone were comparable between PC and control patients. In PC patients, none of the endocrine parameters correlated to serum PSA or clinical/pathological stage.

CONCLUSIONS

Patients with newly diagnosed, untreated PC yielded significantly higher cortisol and lower estradiol serum concentrations than controls. The known effect of cortisol on the immune status warrants further studies.

Short-term effects of intramuscular and transdermal testosterone on bone turnover, prostate symptoms, cholesterol, and hematocrit in men over age 70 with low testosterone levels

The objective of the study was to determine whether short-term testosterone administration to older men with low bioavailable testosterone would have any immediate adverse effects, especially on the symptoms of benign prostate hyperplasia, preliminary to embarking on a long-term study of testosterone treatment. Transdermal and intramuscular testosterone were compared to determine whether there were any rapid changes in markers of bone formation or resorption with either testosterone administration. We undertook a non-randomized trial of 9 weeks intervention with either intramuscular testosterone, transdermal testosterone or neither followed by a 9-week observation period. Twenty-seven men over age 70 years with no medical conditions known to affect bone turnover and total testosterone levels below 350 ng/dl (normal range 350-1230 ng/dl) or bioavailable testosterone levels below 128 ng/dl (normal range 128-430 ng/dl) received either testosterone via transdermal patch (TP; two 2.5 mg patches/d), intramuscular testosterone enanthate (IM; 200 mg every 3 weeks) or no testosterone for 9 weeks of treatment followed by a 9 week observation period. Nine men were enrolled in each group. The mean age of the men was 74 +/- 3 years (range 70-83 years). While all men receiving testosterone treatment increased levels above their own baseline, only 6 of 9 men receiving transdermal testosterone achieved bioavailable testosterone levels in the normal range for young men. Neither treatment group demonstrated changes in estradiol levels. No side effects were reported using the intramuscular testosterone while 5/9 men using transdermal testosterone developed a rash. There were no significant changes in markers of bone resorption or formation in either testosterone treatment group. There were no ill effects on prostate size, symptoms or prostate specific antigen level. PSA levels of 1.5 +/- 0.7 ng/dl and 1.6 +/- 0.7 ng/dl in the TP and IM groups, respectively. were 2.0 +/- 1.0 ng/dl and 1.8 +/- 0.9 ng/dl following treatment. Cholesterol profiles were also not affected by either transdermal or intramuscular testosterone. Similarly hemoglobin and hematocrit remained unchanged in men receiving either testosterone preparation.

Endogenous sex hormones and prostate cancer: a quantitative review of prospective studies

This paper presents a quantitative review of the data from eight prospective epidemiological studies, comparing mean serum concentrations of sex hormones in men who subsequently developed prostate cancer with those in men who remained cancer free. The hormones reviewed have been postulated to be involved in the aetiology of prostate cancer: androgens and their metabolites testosterone (T), non-SHBG-bound testosterone (non-SHBG-bound T), di-hydrotestosterone (DHT), androstanediol glucuronide (A-diol-g), androstenedione (A-dione), dehydroepiandrosterone sulphate (DHEAS), sex hormone binding globulin (SHBG), the oestrogens, oestrone and oestradiol, luteinizing hormone (LH) and prolactin. The ratio of the mean hormone concentration in prostate cancer cases to that of controls (and its 95% confidence interval (CI)) was calculated for each study, and the results summarized by calculating the weighted average of the log ratios. No differences in the average concentrations of the hormones were found between prostate cancer cases and controls, with the possible exception of A-diol-g which exhibited a 5% higher mean serum concentration among cases relative to controls (ratio 1.05, 95% CI 1.00-1.11), based on 644 cases and 1048 controls. These data suggest that there are no large differences in circulating hormones between men who subsequently go on to develop prostate cancer and those who remain free of the disease. Further research is needed to substantiate the small difference found in A-diol-g concentrations between prostate cancer cases and controls.

Endocrine aspects of ageing in the male

There is a statistical decline of testosterone levels in ageing men, most manifest in free testosterone. While this fall is only moderate, ageing men show clinical signs of hypogonadism (loss of muscle mass/strength, reduction in bone mass and an increase in visceral fat). This might represent not only a fall but (also) an impairment of the biological action of androgens in target organs. The first small scale studies of androgen supplement administration in ageing men were not disappointing. Anticipated risks lie with the prostate and the cardiovascular system. The risks with regard to prostate disease are often over-rated. The question remains how the segment of the ageing male population possibly benefiting from androgen supplements, can be identified. For the treatment of postmenopausal women 'designer oestrogens' are being developed; similarly, designer androgens retaining beneficial anabolic effects with elimination of harmful effects on the prostate and cardiovascular system, could be devised.

Age, genetic, and nongenetic factors influencing variation in serum sex steroids and zonal volumes of the prostate and benign prostatic hyperplasia in twins

BACKGROUND

We have observed that hereditary and environmental factors have a substantial influence on the plasma content of sex steroids in normal male twins and in men of families with prostatic disease.

METHODS

The contribution of genetic and nongenetic familial factors on the variation of plasma sex steroid concentrations and of the volume of zones of the prostate measured by transrectal ultrasound (TRUS) has now been investigated in pairs of male monozygotic (MZ) and dizygotic (DZ) twin pairs between age 25-75 years. Bioelectric impedance permitted quantitation of body fat, lean body mass, and water. Morphometrics and testicular volume were also determined.

RESULTS

The intraclass correlation (rI) was > 0.40 for the variation of the total volume (TV), the transition zone (TZ), the peripheral zone (PZ), and the ratio of TZ/PZ in both MZ and DZ twins, and heredity affected 22% of the variation of the PZ and TZ and 30% of the ratio of TZ/PZ. None of the TV and environmental factors influenced the remainder of the variation. Heredity accounted for 25% or more of the variation of dihydrotestosterone (DHT), and the ratios of DHT/testosterone (T), estradiol (E2)/T, androstanediol glucuronide, sex hormone-binding globulin (SHBG)-bound T, T/SHBG, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and dehydroepiandrosterone sulfate (DHEA-S). In MZ twin pairs the variation of the volumes of the prostate became greater with age. In contrast, the variation of the sex hormone concentrations did not show greater variation with age. Heredity also affected > 30% of the variation for waist measurement, weight, body fat, body mass, water and lean body mass, body mass/fat, and testicular size.

CONCLUSIONS

Our results indicated that both MZ and DZ twin pairs had zonal prostate volumes more like their twin pair than like unrelated twins. However, nongenetic factors exerted stronger influences than genetic factors on zonal volumes of the prostate. In contrast, hereditary factors had stronger influences on determining the variation of many sex hormones and morphometric characteristics than did nongenetic factors.