Testosterone replacement therapy for late onset hypogonadism: what is the risk of inducing prostate cancer?

Long-term Exposure to Testosterone Therapy and the Risk of High Grade Prostate Cancer

PURPOSE

To our knowledge no population based studies have been done to examine whether long-term exposure to testosterone therapy is associated with an increased risk of high grade prostate cancer. We examined whether exposure to testosterone during a 5-year period was associated with an increased risk of high grade prostate cancer and whether this risk increased in a dose-response fashion with the cumulative number of testosterone injections.

MATERIALS AND METHODS

Using SEER (Surveillance, Epidemiology and End Results)-Medicare linked data we identified 52,579 men diagnosed with incident prostate cancer between January 1, 2001 and December 31, 2006 who had a minimum of 5 years continuous enrollment in Medicare before the cancer diagnosis. We excluded patients diagnosed at death or after autopsy, those enrolled in a health maintenance organization in the 60 months before diagnosis and those with unknown tumor grade or tumor stage. In the 5 years before diagnosis 574 men had a history of testosterone use and 51,945 did not.

RESULTS

On logistic regression adjusting for demographic and clinical characteristics exposure to testosterone therapy was not associated with an increased risk of high grade prostate cancer (OR 0.84, 95% CI 0.67-1.05) or receipt of primary androgen deprivation therapy following diagnosis (OR 0.97, 95% CI 0.74-1.30). In addition the risk of high grade disease did not increase according to the total number of testosterone injections (OR 1.00, 95% CI 0.98-1.01).

CONCLUSIONS

Our finding that testosterone therapy was not associated with an increased risk of high grade prostate cancer may provide important information regarding the risk-benefit assessment for men with testosterone deficiency considering treatment.

Effects of Long-term Administration of the Antiaging Hormone Dehydroepiandrosterone Sulfate on Rat Prostates and Testes as Androgen-Dependent Organs

Purpose

This study aimed to determine the effects of the long-term use of dehydroepiandrosterone sulfate (DHEAS) on rat prostates and testes as well as on serum testosterone and DHEAS levels.

Materials and Methods

Thirty male rats aged 4 to 5 months were studied. A DHEAS suspension of 5 mg/kg per rat was administered orally to the 15 rats in the experimental group 5 times a week, whereas saline was administered concurrently to the 15 rats in the control group. Intracardiac blood samples were drawn to determine hormone levels, and histological samples of prostate and testes were evaluated under light microscopy.

Results

At the end of the 6-month study period, histological examinations performed on prostate preparations showed that the atrophy score of the experimental group was significantly lower than the scores of the sham and control groups (p<0.001 and p<0.001, respectively). The serum total testosterone and DHEAS levels of the rats in the study group were significantly increased (p<0.001).

Conclusions

In our study, we determined that the long-term use of DHEAS does not have any detrimental effects on the prostate or the testis; on the contrary, it protects the prostate from atrophy, which is imperative for the continuation of fertility as well as for increasing serum testosterone and DHEAS levels.

Changes in prostate specific antigen in hypogonadal men after 12 months of testosterone replacement therapy: support for the prostate saturation theory

PURPOSE

We measured prostate specific antigen after 12 months of testosterone replacement therapy in hypogonadal men.

MATERIALS AND METHODS

Data were collected from the TRiUS (Testim® Registry in the United States), an observational registry of hypogonadal men on testosterone replacement therapy (849). Participants were Testim naïve, had no prostate cancer and received 5 to 10 gm Testim 1% (testosterone gel) daily.

RESULTS

A total of 451 patients with prostate specific antigen and total testosterone values were divided into group A (197 with total testosterone less than 250 ng/dl) and group B (254 with total testosterone 250 ng/dl or greater). The groups differed significantly in free testosterone and sex hormone-binding globulin, but not in age or prostate specific antigen. In group A but not group B prostate specific antigen correlated significantly with total testosterone (r=0.20, p=0.005), free testosterone (r=0.22, p=0.03) and sex hormone-binding globulin (r=0.59, p=0.002) at baseline. After 12 months of testosterone replacement therapy, increase in total testosterone (mean±SD) was statistically significant in group A (+326±295 ng/dl, p<0.001; final total testosterone 516±28 ng/dl) and group B (+154±217 ng/dl, p<0.001; final total testosterone 513±20 ng/dl). After 12 months of testosterone replacement therapy, increase in prostate specific antigen was statistically significant in group A (+0.19±0.61 ng/ml, p=0.02; final prostate specific antigen 1.26±0.96 ng/ml) but not in group B (+0.28±1.18 ng/ml, p=0.06; final prostate specific antigen 1.55±1.72 ng/ml). The average percent prostate specific antigen increase from baseline was higher in group A (21.9%) than in group B (14.1%). Overall the greatest prostate specific antigen was observed after 1 month of treatment and decreased thereafter.

CONCLUSIONS

Patients with baseline total testosterone less than 250 ng/dl were more likely to have an increased prostate specific antigen after testosterone replacement therapy than those with baseline total testosterone 250 ng/dl or greater, supporting the prostate saturation hypothesis. Clinicians should be aware that severely hypogonadal patients may experience increased prostate specific antigen after testosterone replacement therapy.

Differing levels of testosterone and the prostate: a physiological interplay

The controversies surrounding testosterone replacement therapy (TRT) have been addressed in the past few years. Although the androgenic effects of TRT on normal and malignant prostate cells have been studied for over 70 years, little clinical prospective research exists on the physiological responses of prostate tissues to a wide range of serum testosterone levels. The prostate is both an androgen-dependent and an androgen-sensitive organ; active processes are triggered at a 'threshold' or 'saturation' level of testosterone. Despite decades of research, no compelling evidence exists that increasing testosterone beyond this threshold level has a causative role in prostate cancer, or indeed changes the biology of the prostate. Testosterone deficiency has marked physiological and clinical effects on men in middle age and beyond. With subnormal testosterone levels, the potential positive benefits of TRT on factors such as muscle mass, libido or erectile function are likely a dose-response phenomenon, and should be considered differently than the threshold influence on the prostate. This Review will re-examine classic androgen research and reflect on whether testosterone actually stimulates prostatic cellular growth and progression in a 'threshold' or a 'dose-response' (or both) manner, as well as discuss the influence of testosterone on prostate cells in the hypogonadal and eugonadal states.

Update on the safety of testosterone therapy in cardiac disease

INTRODUCTION

Testosterone has been used for decades in the treatment of men with hypogonadism and women with low libido. More recently, it has been used in patient populations with cardiac disease and, in particular, in those patients with heart failure. The benefits of testosterone supplementation have been demonstrated in the literature, but there is also concern that testosterone supplementation may not be benign, especially when administered to achieve supraphysiological levels, e.g., to improve athletic performance.

AREAS COVERED

This review seeks to address the link between testosterone levels and cardiac disease while discussing the safety concerns of testosterone supplementation in clinical practice. Randomized controlled trials, systematic reviews and meta-analyses that were obtained through a literature search of the Medline database are discussed in this paper.

EXPERT OPINION

Ultimately, the definitive role of testosterone in cardiovascular disease remains contentious, but testosterone may have niche roles in certain conditions, such as advanced heart failure and cardiac cachexia. Testosterone has been used safely, and we believe may continue to be used safely, in men with cardiac disease when achieving physiological levels, with adequate monitoring of prostate specific antigen and hematocrit levels during the course of treatment per established clinical guidelines. Testosterone might exert beneficial effects on physical capacity and functioning as well as overall outcomes in patients with chronic heart failure.

Short term testosterone replacement therapy improves libido and body composition

OBJECTIVE

To assess the efficacy and safety of testosterone replacement in males with late-onset hypogonadism compared to hypogonadal men without replacement, and controls, during six months.

METHODS

We assessed, through ADAM, AMS, IIEF-5 and SF-36 questionnaires, and through clinical and laboratory examinations, 62 patients divided into three groups: 17 hypogonadal males (HR) used intramuscular testosterone every three weeks; 14 hypogonadal males (HV) and 31 non-hypogonadal males (CV) used oral vitamins daily.

RESULTS

When compared to others, HR group obtained libido improvement assessed by ADAM 1 (p = 0.004), and borderline sexual potency improvement assessed by IIEF-5 (p = 0.053), besides a decrease in waist circumference after eight weeks (p = 0.018). The remaining parameters did not differ between the groups. PSA and hematocrit remained stable in those using testosterone.

CONCLUSION

Six months of testosterone replacement improved sexuality and body composition, with prostatic and hematological safety.

Lower urinary tract symptoms after hormone replacement therapy in Japanese patients with late-onset hypogonadism: a preliminary report

Hormone replacement therapy (HRT) is performed for the treatment for patients with late onset hypogonadism (LOH). One of the main concerns about HRT is the influence of lower urinary tract including prostate. This study examined whether HRT for Japanese patients of LOH affected lower urinary tract symptoms. A total of 21 patients with LOH were included in this study. Changes of International prostate symptom score (IPSS), IPSS quality of life (QOL) index and King's health questionnaire (KHQ), before HRT and 3 months after HRT, were evaluated. Statistical comparisons were made using the Wilcoxon signed rank test, P < 0.05 was considered statistically significant. Total IPSS and QOL index were not significantly different from 7.43 +/- 6.56, 2.71 +/- 1.74 at baseline to 8.29 +/- 6.24, 2.91 +/- 1.13 after 3 months. There were no significant differences in any of the nine categories of KHQ. In this preliminary study, the results suggested that HRT for LOH had no short-term effects on patients with lower urinary symptoms.

Testosterone deficiency syndrome: treatment and cancer risk

Testosterone deficiency syndrome (TDS) can be linked to premature mortality and to a number of co-morbidities (such as sexual disorders, diabetes, metabolic syndrome, ...). Testosterone deficiency occurs mainly in ageing men, at a time when prostate disease (benign or malign) start to emerge. New testosterone preparations via different route of administration appeared during the last decade allowing optimized treatment to these patients. One potential complication of this treatment is the increased risk of prostate and breast cancer. Consequently, the guidelines from the agencies and the institutions, the recommendations of the scientific expert committees and the attitude of the clinicians to who, when and how to treat hypogonadal patients, is very conservative, not to say, highly restrictive. To date, as documented in many reviews on the subject, nothing has been found to support the evidence that restoring testosterone levels within normal range increases the incidence of prostate cancer. In our experience, during a long-term clinical study including 200 hypogonadal patients receiving a patch of testosterone, 50 patients ended 5 years of treatment and no prostate cancer have been reported. In fact, the incidence of prostate cancer in primary or secondary testosterone treated hypogonadal men is lower than the incidence observed in the untreated eugonadal population. However, even if the number of patients treated in well-conducted clinical trials for whom cancer of the prostate has been reported is insignificant (a very few), the observed population is still too small to raise definite conclusions. Low testosterone levels have been reported in patients undergoing radical prostatectomy and the outcomes are of worse diagnostic in this population; at a later stage, testosterone deficiency can be induced by anti hormonal manipulation of patient with a prostate cancer, leading to the symptoms of hypogonadism. The question is to know whether it is justified, in case of profound symptoms, to supplement those patients with testosterone. Some attempts have been made and the results are encouraging: so it is time to re-examine our position and to question about the definite recommendation that patients with prostate cancer should never receive testosterone supplementation therapy; this is already the situation when intermittent androgen blockade is initiated if the biological response is satisfactory. Furthermore, it has been advocated that, under a rigorous surveillance, patients cured of prostate cancer can be treated with testosterone supplementation with beneficial results.

Testosterone therapy in hypogonadal men and potential prostate cancer risk: a systematic review

This paper provides a systematic review of the literature about prostate cancer risk associated with testosterone therapy for hypogonadism. A comprehensive search of MEDLINE, EMBASE and other resources was conducted to identify articles that highlight occurrences of prostate cancer in men receiving testosterone therapy for hypogonadism treatment. Articles that met study inclusion criteria were assessed for causality between testosterone treatment and prostate cancer, increased prostate-specific antigen or abnormal digital rectal examination findings. Of 197 articles relating to testosterone therapy, 44 met inclusion criteria: 11 placebo-controlled, randomized studies; 29 non-placebo-controlled studies of men with no prostate cancer history; and 4 studies of hypogonadal men with history of prostate cancer. Of studies that met inclusion criteria, none demonstrated that testosterone therapy for hypogonadism increased prostate cancer risk or increased Gleason grade of cancer detected in treated vs untreated men. Testosterone therapy did not have a consistent effect on prostate-specific antigen levels.

Histopathological evidence for an association of inflammation with ductal pin-like lesions but not with ductal adenocarcinoma in the prostate of the noble rat

BACKGROUND

Chronic inflammation may contribute to the development of prostate cancer. The goal of this study was to determine the possible association of prostatic inflammation, prostatic intraepithelial neoplasia (PIN)-like lesion, and prostate cancer, and to assess the androgen and estrogen dependency of the early steps of carcinogenesis.

METHODS

Noble rats were treated with testosterone and estradiol implants for 13, 18, or 26 weeks. Hormone dependency of the lesions was studied in a subset of animals by removing hormone implants for 3 weeks after 15 weeks treatment time.

RESULTS

After treatment for 13 weeks, acute and chronic inflammation was found in the dorsolateral prostate lobes and both inflammation and PIN-like lesions were present in the periurethal area of the prostate in all animals (n = 8). Following hormone exposure for 18 and 26 weeks, inflammation in the prostate remained, and adenocarcinomas in the periurethal prostate area with no adjacent inflammation were observed in all 18 animals studied. When both hormone implants were removed after 15 weeks, PIN-like lesions progressed further to adenocarcinoma only in two of seven animals. When only the estradiol implants were removed, three of five animals developed adenocarcinomas.

CONCLUSIONS

Even though adenocarcinomas were not morphologically associated with inflammation, PIN-like lesions preceding adenocarcinoma were found in close association with inflammation, pointing towards a possible initiator role of inflammation in the early steps of prostatic carcinogenesis. Further, these results indicate that both androgens and estrogens together play a significant role in the induction of inflammation and prostatic cancer in this model.

Prostate cancer risk in testosterone-treated men

Men with classical androgen deficiency have reduced prostate volume and blood prostate-specific antigen (PSA) levels compared with their age peers. As it is plausible that androgen deficiency partially protects against prostate disease, and that restoring androgen exposure increases risk to that of eugonadal men of the same age, men using ART should have age-appropriate surveillance for prostate disease. This should comprise rectal examination and blood PSA measurement at regular intervals (determined by age and family history) according to the recommendations, permanently revisited, published by ISSAM, EAU, Endocrine Society.... Testosterone replacement therapy is now being prescribed more often for aging men, the same population in which prostate cancer incidence increases; it has been suggested that administration in men with unrecognised prostate cancer might promote the development of clinically significant disease. In hypogonadal men who were candidates for testosterone therapy, a 14% incidence of occult cancer was found. A percentage (15.2%) of prostate cancer has been found in the placebo group (with normal DRE and PSA) in the prostate cancer prevention study investigating the chemoprevention potential of finasteride. The hypothesis that high levels of circulating androgens is a risk factor for prostate cancer is supported by the dramatic regression, after castration, of tumour symptoms in men with advanced prostate cancer. However these effects, seen at a very late stage of cancer development, may not be relevant to reflect the effects of variations within a physiological range at an earlier stage. Data from all published prospective studies on circulating level of total and free testosterone do not support the hypothesis that high levels of circulating androgens are associated with an increased risk of prostate cancer. A study on a large prospective cohort of 10,049 men, contributes to the gathering evidence that the long standing "androgen hypothesis" of increasing risk with increasing androgen levels can be rejected, suggesting instead that high levels within the reference range of androgens, estrogens and adrenal androgens decrease aggressive prostate cancer risk. Indeed, high-grade prostate cancer has been associated with low plasma level of testosterone. Furthermore, pre-treatment total testosterone was an independent predictor of extraprostatic disease in patients with localized prostate cancer; as testosterone decreases, patients have an increased likelihood of non-organ confined disease and low serum testosterone levels are associated with positive surgical margins in radical retropubic prostatectomy. A clinical implication of these results concerns androgen supplementation which has become easier to administer with the advent of transdermal preparations (patch or gel) that achieve physiological testosterone serum levels without supra physiological escape levels. During the clinical development of a new testosterone patch in more than 200 primary or secondary hypogonadal patients, no prostate cancer was diagnosed.

Testosterone therapy for men at risk for or with history of prostate cancer

Since the early 1940s when Huggins showed that severe reductions in serum testosterone by castration or estrogen therapy caused regression of prostate cancer (PCa), it has been assumed that higher testosterone levels cause enhanced growth of PCa. For this reason, it has been considered taboo to offer testosterone replacement therapy (TRT) to any man with a prior history of PCa, even if all objective evidence suggests he has been cured. The fear has been that higher testosterone levels would "awaken" dormant cells and cause a recurrence. Thus, US Food and Drug Administration-mandated language in all testosterone package inserts states that testosterone is contraindicated in men with a history of, or suspected of having, PCa. Although there is little modern experience with administration of testosterone in men with known history of PCa, there is a varied and extensive literature indicating that TRT does not pose any increased risk of PCa growth in men with or without prior treatment. For instance, the cancer rate in TRT trials is only approximately 1%, similar to detection rates in screening programs, yet biopsy-detectable PCa is found in one of seven hypogonadal men. Moreover, PCa is almost never seen in the peak testosterone years of the early 20s, despite autopsy evidence that men in this age group already harbor microfoci of PCa in substantial numbers. The growing number of PCa survivors who happen to be hypogonadal and request treatment has spurred a change in attitude toward this topic, with increasing numbers of physicians now offering TRT to men who appear cured of their disease. Publications have now reported no prostate-specific antigen (PSA) recurrence with TRT in small numbers of men who had undetectable PSA values after radical prostatectomy. Although still controversial, there appears to be little reason to withhold TRT from men with favorable outcomes after definitive treatment for PCa. Monitoring with PSA and digital rectal examination at regular intervals is recommended.