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

Low Testosterone Alters the Activity of Mouse Prostate Stem Cells

BACKGROUND

Low serum testosterone (low T) has been repeatedly linked to worse outcomes in men with newly diagnosed prostate cancer (PC). How low T contributes to these outcomes is unknown. Here we demonstrate that exposure to low T causes significant changes in the mouse prostate and prostate stem cells.

METHODS

Mice were castrated and implanted with capsules to achieve castrate, normal, or sub-physiological levels of T. After 6 weeks of treatment, LC-MS/MS was used to quantify the levels of T and dihydrotestosterone (DHT) in serum and prostate tissue. FACS was used to quantify the percentages of purported prostate stem and transit amplifying (TA) cells in mouse prostates. Prostate tissues were also stained for the presence of CD68+ cells and RNA was extracted from prostate tissue or specific cell populations to measure changes in transcript levels with low T treatment.

RESULTS

Despite having significantly different levels of T and DHT in the serum, T and DHT concentrations in prostate tissue from different T treatment groups were similar. Low T treatment resulted in significant alterations in the expression of androgen biosynthesis genes, which may be related to maintaining prostate androgen levels. Furthermore, the expression of androgen-regulated genes in the prostate was similar among all T treatment groups, demonstrating that the mouse prostate can maintain functional levels of androgens despite low serum T levels. Low T increased the frequency of prostate stem and TA cells in adult prostate tissue and caused major transcriptional changes in those cells. Gene ontology analysis suggested that low T caused inflammatory responses and immunofluorescent staining indicated that low T treatment led to the increased presence of CD68+ macrophages in prostate tissue.

CONCLUSIONS

Low T alters the AR signaling axis which likely leads to maintenance of functional levels of prostate androgens. Low T also induces quantitative and qualitative changes in prostate stem cells which appear to lead to inflammatory macrophage infiltration. These changes are proposed to lead to an aggressive phenotype once cancers develop and may contribute to the poor outcomes in men with low T. Prostate 77:530-541, 2017. © 2016 Wiley Periodicals, Inc.

Low serum testosterone is associated with tumor aggressiveness and poor prognosis in prostate cancer

Serum testosterone is a potential marker to distinguish between indolent and aggressive prostate cancer (PCa). The present study aimed to investigate whether low levels of total serum testosterone at diagnosis were associated with aggressive PCa and poor clinical outcomes. In total, 762 non-Hispanic Caucasian men with previously untreated PCa were recruited from The University of Texas MD Anderson Cancer Center (Houston, TX, USA). Patients were categorized into three groups based on their total serum testosterone levels according to clinical guidelines [low (<230 ng/dl), intermediate (230-350 ng/dl) and normal (>350 ng/dl)]. PCa aggressiveness (low-, intermediate- or high-risk, or metastatic) was compared using multinomial logistic regression. Rates of disease progression, mortality from any cause and PCa-specific mortality were compared using the multivariate Cox proportional hazards model. Testosterone levels significantly decreased as PCa aggressiveness increased (P<0.001). Compared with the normal testosterone group, the low testosterone group had 2.9-fold (OR, 2.92; 95% CI, 1.74-4.90; P<0.001), 5.6-fold (OR, 5.63; 95% CI, 3.14-10.12; P<0.001) and 72.4-fold (OR, 72.40; 95% CI, 20.89-250.89; P<0.001) increased risks of having intermediate-risk, high-risk and metastatic PCa, respectively. Furthermore, low levels of testosterone were significantly associated with a 10.7-fold (HR, 10.68; 95% CI, 1.35-84.44; P=0.03) increased risk of PCa-specific mortality. The results of the present study indicate that low levels of total serum testosterone at diagnosis are associated with aggressive PCa and predict poor PCa-specific survival.

The association of diabetes and obesity with prostate cancer aggressiveness among Black Americans and White Americans in a population-based study

PURPOSE

Few studies have investigated the role of race in the association of diabetes and obesity with prostate cancer aggressiveness. Here we evaluate the independent association between diabetes and obesity with prostate cancer aggressiveness in White Americans and Black Americans.

METHODS

Our cross-sectional, case-only study consisted of 1,058 White Americans and 991 Black Americans from the North Carolina-Louisiana Prostate Cancer (PCaP) project. Diabetes status was determined by self-report. Obesity was determined using body mass index and calculated based on anthropometric measurements. High aggressive prostate cancer was defined as Gleason sum ≥8, or prostate-specific antigen >20 ng/ml, or Gleason sum = 7 and clinical stage cT3-cT4. The association between diabetes and obesity with high aggressive prostate cancer at diagnosis was evaluated using multivariable logistic regression and adjusted for potential confounders.

RESULTS

Diabetes was not associated with high aggressive prostate cancer in the overall sample (OR 1.04; 95% CI 0.79, 1.37), White Americans (OR 1.00; 95% CI 0.65, 1.57) or Black Americans (OR 1.07; 95% CI 0.75, 1.53). Obesity, independent of diabetes, was positively associated with high aggressive prostate cancer in White Americans (OR 1.98; 95% CI 1.14, 3.43), but not in the overall sample (OR 1.37; 95% CI 0.99, 1.92) or Black Americans (OR 1.09; 95% CI 0.71, 1.67).

CONCLUSIONS

Diabetes was not associated with prostate cancer aggressiveness, overall, or in either race group. Obesity, independent of diabetes, was associated with high aggressive prostate cancer only in White Americans.

Prostate Cancer: Is It a Battle Lost to Age?

Age is often considered an important non-modifiable risk factor for a number of diseases, including prostate cancer. Some prominent risk factors of prostate cancer include familial history, ethnicity and age. In this review, various genetic and physiological characteristics affected due to advancing age will be analysed and correlated with their direct effect on prostate cancer.

Hormonal changes after localized prostate cancer treatment. Comparison between external beam radiation therapy and radical prostatectomy

OBJECTIVE

To determine the influence of radical prostatectomy (RP) and external beam radiation therapy (EBRT) on the hypothalamic pituitary axis of 120 men with clinically localized prostate cancer treated with RP or EBRT exclusively.

MATERIALS AND METHODS

120 patients with localized prostate cancer were enrolled. Ninety two patients underwent RP and 28 patients EBRT exclusively. We measured serum levels of luteinizing hormone, follicle stimulating hormone (FSH), total testosterone (T), free testosterone, and estradiol at baseline and at 3 and 12 months after treatment completion.

RESULTS

Patients undergoing RP were younger and presented a higher prostate volume (64.3 vs. 71.1 years, p<0.0001 and 55.1 vs. 36.5 g, p<0.0001; respectively). No differences regarding serum hormonal levels were found at baseline. Luteinizing hormone and FSH levels were significantly higher in those patients treated with EBRT at three months (luteinizing hormone 8,54 vs. 4,76 U/l, FSH 22,96 vs. 8,18 U/l, p<0,0001) while T and free testosterone levels were significantly lower (T 360,3 vs. 414,83ng/dl, p 0,039; free testosterone 5,94 vs. 7,5pg/ml, p 0,018). At 12 months FSH levels remained significantly higher in patients treated with EBRT compared to patients treated with RP (21,01 vs. 8,51 U/l, p<0,001) while T levels remained significantly lower (339,89 vs. 402,39ng/dl, p 0,03).

CONCLUSIONS

Prostate cancer treatment influences the hypothalamic pituitary axis. This influence seems to be more important when patients with prostate cancer are treated with EBRT rather than RP. More studies are needed to elucidate the role that prostate may play as an endocrine organ.

Association between late-onset hypogonadism syndrome plus metabolic syndrome and prostate cancer and its aggressiveness

OBJECTIVE

To assess the relationship between prostate cancer (PC) and the presence of metabolic syndrome and late-onset hypogonadism (LOH) syndrome.

MATERIAL AND METHOD

A retrospective study was conducted on 686 patients who underwent prostate biopsy. We analysed the demographic variables, clinical data and biopsy results. To diagnose metabolic syndrome, we employed the criteria of the American Heart Association. For the diagnosis of LOH syndrome, we employed the Androgen Deficiency in the Aging Male questionnaire and testosterone levels (TT). We evaluated the relationship between free testosterone (FT) and bioavailable testosterone (BT) on one hand and PC and its aggressiveness on the other, as well as the usefulness of the TT to prostate specific antigen (TT/PSA) ratio in the PC diagnosis.

RESULTS

The patient's median age was 65 years. Metabolic syndrome is not associated with PC (39.4% vs. 35%; P=.1) but is associated with a PC Gleason score >7 (50.4% vs. 29.44%; P=.002). LOH, low FT and low BT are associated with an increased presence of PC (51% vs. 35%, P=.02; 44.86% vs. 33.33%, P=.03; and 46.46% vs. 33.08%, P=.01, respectively) and with an increased probability of a PC Gleason score >7 (61.54% vs. 37.5%, P=.02; 54.17% vs. 34.12%, P=.02; 54.35% vs. 34.48%, P=.02, respectively). Additionally, the median TT/PSA ratio was significantly lower in patients with positive biopsies (P=.022).

CONCLUSIONS

Metabolic syndrome was not associated with the probability of having PC but was associated with a PC Gleason score >7. Moreover, LOH syndrome had a higher percentage of PC and a greater presence of PC Gleason scores >7, as did low levels of FT and low levels of BT.

Advances in hormonal therapies for hormone naïve and castration-resistant prostate cancers with or without previous chemotherapy

Hormonal manipulation plays a significant role in the treatment of advanced hormone naïve prostate cancer and castration-resistant prostate cancer (CRPC) with or without previous chemotherapy. Combination of gonadotropin releasing hormone (GnRH) agonists and androgen receptor (AR) antagonists (combined androgen blockade; CAB) is the first line therapy for advanced hormone naïve prostate cancer, but current strategies are developing novel GnRH antagonists to overcome disadvantages associated with GnRH agonist monotherapy and CAB in the clinical setting. Abiraterone acetate and enzalutamide are hormonal agents currently available for patients with CRPC and are both shown to improve overall survival versus placebo. Recently, in clinical trials, testosterone has been administered in cycles with existing surgical and chemical androgen deprivation therapies (ADT) (intermittent therapy) to CRPC patients of different stages (low risk, metastatic) to abate symptoms of testosterone deficiency and reduce cost of treatment from current hormonal therapies for patients with CRPC. This review will provide an overview on the therapeutic roles of hormonal manipulation in advanced hormone naïve and castration-resistant prostate cancers, as well as the development of novel hormonal therapies currently in preclinical and clinical trials.

Association between baseline serum glucose, triglycerides and total cholesterol, and prostate cancer risk categories

Lifestyle-related risk factors such as hyperglycemia and dyslipidemia have been associated with several cancers. However, studies exploring their link with prostate cancer (PCa) clinicopathological characteristics are sparse and inconclusive. Here, we investigated the associations between serum metabolic markers and PCa clinicopathological characteristics. The study comprised 14,294 men from the Swedish Apolipoprotein MOrtality RISk (AMORIS) cohort who were diagnosed with PCa between 1996 and 2011. Univariate and multivariable logistic regression were used to investigate the relation between glucose, triglycerides and total cholesterol and PCa risk categories, PSA, Gleason score, and T-stage. Mean age at time of PCa diagnosis was 69 years. Men with glucose levels >6.9 mmol/L tend to have PSA<4 μg/L, while those with glucose levels of 5.6-6.9 mmol/L had a greater odds of PSA>20 μg/L compared to PSA 4.0-9.9 μg/L. Hypertriglyceridemia was also positively associated with PSA>20 μg/L. Hyperglycemic men had a greater odds of intermediate- and high-grade PCa and advanced stage or metastatic PCa. Similarly, hypertriglyceridemia was positively associated with high-grade PCa. There was also a trend toward an increased odds of intermediate risk localized PCa and advanced stage PCa among men with hypertriglyceridemia. Total cholesterol did not have any statistically significant association with any of the outcomes studied. Our findings suggest that high serum levels of glucose and triglycerides may influence PCa aggressiveness and severity. Further investigation on the role of markers of glucose and lipid metabolism in influencing PCa aggressiveness and severity is needed as this may help define important targets for intervention.

Prostate cancer volume associates with preoperative plasma levels of testosterone that independently predicts high grade tumours which show low densities (quotient testosterone/tumour volume)

OBJECTIVE

To investigate potential associations of preoperative total testosterone (TT) with tumor volume (TV) and grade of prostate cancer (PCa).

METHODS

Patients who were under medications impacting on the hypothalamic-pituitary-adrenal-testis-prostate axis were excluded. TT was measured preoperatively at least 1 month after biopsies and TV was calculated on the removed prostate specimen. Other continuous variables included total prostate specific antigen (PSA), percentage of positive cores (P+) and weight (W) of the removed prostate. Patients were categorized according to the pathologic Gleason score (pGS) in 3 groups (pGS 6, 7 and > 7). Invasion of the seminal vesicles was coded as seminal vesicle invasion (SVI).

RESULTS

The median levels of TT were significantly and increasingly higher from pGS 6 (14.7 nmol/L) to pGS 7 (15.0 nmol/L) and pGS > 7 (18.8 nmol/L). The median values of TV were also detected significantly and increasingly higher from pGS 6 (5.6 mL) to pGS 7 (8.1 mL) and pGS > 7 (14.8 mL). The median preoperative levels of PSA were also increasing from pGS 6 (5.9 μg/L) to pGS 7 (6.2 μg/L) and pGS > 7 (7.7 μg/L). There was a significant and positive correlation of TV to PSA, TT and P+. Multiple linear regression analysis showed that TV was significantly and independently predicted by TT, PSA and P+. High grade PCa (pGS > 7) independently associated with TV, TT, P+ and SVI. The median density values of TT relative to TV (quotient TT/TV) significantly decreased from pGS 6 (2.6 nmol/L/mL) to pGS 7 (1.9 nmol/L/mL) and pGS > 7 (1.4 nmol/L/mL). The median density values of PSA relative to TV (quotient PSA/TV) also significantly decreased from pGS (1.1 μg/L/mL) to pGS 7 (0.7 μg/L/mL) and pGS > 7 (0.6 μg/L/mL).

CONCLUSION

The investigation shows that TT relates to volume and grade of PCa; moreover, the density of TT relative to TV inversely associates with rate of increase of cancer that depends on the grade of the tumour.

Obesity and Prostate Cancer

Prostate cancer is a complex, heterogeneous disease. Factors related to detection, particularly PSA screening, further increase heterogeneity in the manifestation of the disease. It is thus not possible to provide a simple summary of the relationship between obesity and prostate cancer. Findings on obesity, often defined using body mass index (BMI), and total prostate cancer risk have been mixed; however, obesity is relatively consistently associated with a higher risk of aggressive prostate cancer, with aggressiveness defined in various ways (e.g., advanced stage, fatal, poorer prognosis in men with prostate cancer). Many methodologic issues (e.g., influence of PSA screening, detection bias and treatment) need to be thoroughly considered in both existing and future etiologic and prognostic research. Biological mechanisms supporting the link are under investigation, but may involve insulin and IGF axis, sex steroid hormones and alterations in metabolism. Some promising data suggest that molecular sub-types of prostate cancer may offer insights into etiology, but further study is required. A full evaluation of body fatness and weight change over the life course would not only provide insights to the underlying mechanisms but also allow more effective interventions.

Complex relationship between sex hormones, insulin resistance and leptin in men with and without prostatic disease

OBJECTIVES

To assess sex hormones, leptin and insulin-resistance in men with prostate cancer (PCa) and benign prostatic hyperplasia (BPH) and to study associations between androgens and histologic score of prostate tissue in PCa.

SUBJECTS AND METHODS

Two hundred ten men older than 45 years selected from 2906 participants of a population screening for PCa were studied: 70 with PCa, 70 with BPH and 70 controls (CG), matched by body mass index and age. Insulin, IGF-1, PSA, leptin, total, free (fT) and bioavailable testosterone (bT) and estradiol were measured. Each group was subdivided into two subgroups considering the presence of metabolic syndrome (MS); androgens and leptin levels were analyzed in the subgroups.

RESULTS

Prostate cancer and BPH patients presented higher total, fT and bT levels than CG. IGF-1, insulin and HOMA index were higher in BPH than in the other two groups. PCa presented higher leptin [median (range) 6.5 (1.3-28.0) versus 4.8 (1.1-12.3) ng/ml; p < 0.01] and estradiol [median (range) 37.0 (20-90) versus 29.0 (20-118) pg/ml; p = 0.025] levels than CG. After dividing men considering the presence of MS, leptin was higher and total testosterone was lower in MS patients in all the groups.

CONCLUSIONS

It was observed a coexistence of an altered hormone profile with increased sex hormones and leptin in PCa patients, in accordance with the new perspective of PCa pathogenesis.

Behavior of total and free serum testosterone as a predictor for the risk of prostate cancer and its aggressiveness

CONTEXT

Serum testosterone is mostly bound to the sex hormone-binding globulin and albumin. A small metabolically active part is present in the form of free testosterone (FT). The relationship between serum total testosterone (TT) levels and prostate carcinogenesis is debated. Our hypothesis is that the serum FT concentration is more closely associated with the risk of prostate cancer (PC) and its aggressiveness than TT.

OBJECTIVE

To analyze the scientific evidence that relates serum TT and/or FT levels with the diagnosis of PC and its aggressiveness.

ACQUISITION OF EVIDENCE

A systematic review was conducted in PubMed up to January 2015 using the following mesh terms: prostate cancer, sex hormone, androgen, testosterone and free testosterone.

SYNTHESIS OF THE EVIDENCE

We found 460 publications, 124 of which were reviewed to analyze the evidence. The relationship between serum TT levels and the diagnosis of PC and its aggressiveness is highly heterogeneous. The variability in the design of the studies, the quantification methods and other variables could explain this heterogeneity. In a number of studies that evaluated the estimated or measured FT, the evidence remains equally conflicting.

CONCLUSIONS

Based on the current evidence, we cannot recommend the measurement of serum TT and/or TL levels for the diagnosis of PC or for assessing its aggressiveness.

Preoperative low serum testosterone is associated with high-grade prostate cancer and an increased Gleason score upgrading

BACKGROUND

To compare histological feature of prostate cancer (PCa) according androgenic status in patients who underwent radical prostatectomy (RP).

METHODS

Between March 2007 and September 2013, we prospectively analysed 937 patients who were referred to our centre for RP. Clinical, pathological and biological data have been prospectively collected. Preoperative total testosterone (TT) and bioavailable testosterone (BT) serum determinations were carried out. The threshold for low serum testosterone was set at TT<3 ng/ml. Preoperative PSA value was registered. Gleason score (GS) and predominant Gleason pattern were determined in prostate biopsies and in prostate tissue specimens, crosschecked by two uro-pathologists.

RESULTS

Nine hundred and thirty-seven consecutive patients were included. In all, 14.9% patients had low TT in the population. An exact match between biopsy and prostate specimens in GS grading was observed for 50.6% patients (n=474). Also, 40.9% of all patients were upgraded (n=383): 45.3% (n=63) in low serum testosterone patients and 40.1% (n=320) in normal serum testosterone patients. For prostate specimens, the proportion of patients with predominant Gleason pattern 4 was higher in patients with low TT compared with normal TT (41.7% vs 29.1%, P=0.0029). In all, 20.1% were upgraded from predominant Gleason pattern 3 on biopsies specimen to predominant Gleason 4 pattern on the prostate specimen in patients with low TT, whereas 11.6% were upgraded for normal TT patients (P=0.002).

CONCLUSIONS

Low serum testosterone is an independent risk factor for predominant Gleason pattern 4 on prostate specimen after RP and for upgrading from low- to high-grade cancer between prostate needle biopsies and RP specimen. This observation should be taken into account in localised PCa management, especially for active surveillance or when a nerve-sparing approach is considered.

Nadir Testosterone after Long-Term Followup Predicts Prognosis in Patients with Prostate Cancer Treated with Combined Androgen Blockade

PURPOSE

We examined the clinical significance of long-term serum testosterone monitoring to predict the prognosis of patients with prostate cancer treated with combined androgen blockade.

MATERIALS AND METHODS

We retrospectively analyzed the records of 225 patients who underwent combined androgen blockade as first line therapy for prostate cancer. The prognostic values of testosterone and other clinical factors were evaluated with respect to prostate specific antigen progression-free and overall survival.

RESULTS

Median patient age was 73.0 years, median prostate specific antigen was 42.6 ng/ml and median followup was 45.8 months. No variable associated with testosterone was predictive of progression-free survival. With regard to overall survival on univariate analysis nadir testosterone less than 16 ng/dl (p = 0.0190), less than 20 ng/dl (p = 0.0020) and less than 32 ng/dl (p = 0.0146) were significant together with other clinical factors. In contrast, nadir testosterone less than 8 and less than 12 ng/dl were not significant. Multivariate analysis showed that nadir testosterone less than 20 ng/dl was the significant prognostic factor (p = 0.0048). In addition, time to nadir testosterone was about 1 year (11.3 months). Patients were divided into rapid and slow types based on time to testosterone less than 20 ng/dl before and after 6 months, respectively. No significant difference in overall survival was observed between the 2 types. The current results suggest that the critical factor for prognosis was not a rapid decrease but whether nadir testosterone achieved a level of less than 20 ng/dl.

CONCLUSIONS

Nadir testosterone 20 ng/dl was the most significant cutoff level for overall survival in Japanese patients with prostate cancer treated with combined androgen blockade.

Androgens and androgen receptor signaling in prostate tumorigenesis

Androgens and androgen receptor (AR) signaling are necessary for prostate development and homeostasis. AR signaling also drives the growth of nearly all prostate cancer cells. The role of androgens and AR signaling has been well characterized in metastatic prostate cancer, where it has been shown that prostate cancer cells are exquisitely adept at maintaining functional AR signaling to drive cancer growth. As androgens and AR signaling are so intimately involved in prostate development and the proliferation of advanced prostate cancer, it stands to reason that androgens and AR are also involved in prostate cancer initiation and the early stages of cancer growth, yet little is known of this process. In this review, we summarize the current state of knowledge concerning the role of androgens and AR signaling in prostate tissue, from development to metastatic, castration-resistant prostate cancer, and use that information to suggest potential roles for androgens and AR in prostate cancer initiation.

Combined blockade of testicular and locally made androgens in prostate cancer: a highly significant medical progress based upon intracrinology

Recently two drugs, namely the antiandrogen MDV-3100 and the inhibitor of 17α-hydroxylase abiraterone have been accepted by the FDA for the treatment of castration-resistant prostate cancer (CRPC) with or without previous chemotherapy, with a prolongation of overall survival of 2.2-4.8 months. While medical (GnRH agonist) or surgical castration reduces the serum levels of testosterone by about 97%, an important concentration of testosterone and dihydrotestosterone remains in the prostate and activates the androgen receptor (AR), thus offering an explanation for the positive data obtained in CRPC. In fact, explanation of the response observed with MDV-3100 or enzalutamide in CRPC is essentially a blockade of the action or formation of intraprostatic androgens. In addition to the inhibition of the action or formation of androgens made locally by the mechanisms of intracrinology, increased AR levels and AR mutations can be involved, especially in very advanced disease. Future developments look at more efficient inhibitors of the action or formation of intraprostatic androgens and starting treatment earlier when blockade of androgens can exert long-term control and even cure prostate cancer treated at a stage before the appearance of metastases. This article is part of a Special Issue entitled 'Essential role of DHEA'.

Alterations in gene expression during sexual differentiation in androgen receptor knockout mice induced by environmental endocrine disruptors

In the present study, we aimed to explore the effect of environmental endocrine disruptors (EEDs) on sexual differentiation in androgen receptor (AR)-/-, AR+/- and AR+/+ male mice. By using a Cre-loxP conditional knockout strategy, we generated AR knockout mice. By mating flox-AR female mice with AR-Cre male mice, the offspring male mice which were produced were examined. Mice not subjected to any type of intervention were used as the controls. Furthermore, male mice of different genotypes were selected and further divided into subgroups as follows: the control group, bisphenol A (BPA) group and the dibutyl phthalate [corrected] (DBP) group. The expression of the Wilms tumor 1 (WT1), lutropin/choriogonadotropin receptor (LHR), 17-β-hydroxysteroid dehydrogenase type 3 (17βHSD3) and steroid-5-alpha-reductase, alpha polypeptide 2 (SRD5A2) genes was determined by RT-qPCR and western blot analysis. There was no statistically significant difference in the weight of the mice between the control group and the knockout group (P>0.05). The results revealed that, compared with the control group, in the knockout group, anogenital distance was shortened, and testicular weight and testosterone levels were decreased; estradiol levels were elevated; the differences were statistically significant (P<0.05). In the group of AR+/- male mice exposed to 100 mg/l EEDs, hypospadias was successfully induced, suggesting that EEDs are involved in the embryonic stage of sexual development in male mice. The quantitative detection of WT1, LHR, 17βHSD3 and SRD5A2 gene expression by RT-qPCR and western blot analysis indicated that these genes were significantly downregulated in the mice in the BPA group. In conclusion, exposure to EEDs induces hypospadias in heterozygous and wild-type male mice offspring during sexual differentiation, but has no effect on homozygous offspring. Therefore, EEDs play an important role during the third stage of sexual differentiation.

Serum levels of sex hormone binding globulin (SHBG) are not predictive of prostate cancer diagnosis and aggressiveness: results from an Italian biopsy cohort

PURPOSE

To explore the association between serum levels of Sex Hormone Binding Globulin (SHBG) and the risk of developing prostate cancer (PCa) as well as high grade disease in men undergoing prostate biopsy.

MATERIALS AND METHODS

Between 2006 and 2012, we prospectively enrolled 740 patients with no history of PCa undergoing prostate biopsy. Before biopsy general data of the patient DRE, PSA and BMI were recorded. The risk of detecting cancer and high grade cancer was assessed as a function of SHBG using crude and adjusted logistic regressions.

RESULTS

Serum levels of SHBG were not associated with an increased risk of PCa or high grade disease. Age (OR 1.027 95% CI 1.003-1.052 p = 0.027), DRE (OR 3.391 95% CI 2.258-5.092 p = 0.000) and PSA (OR 1.078 95% CI 1.037-1.120 p = 0.000) were found to be independent predictors of prostate cancer risk. Age (OR 1.051 95% CI 1.009-1.095 p = 0.016), DRE (OR 2.519 95% CI 1.384-4.584 p = 0.000), BMI (OR 1.098 95% CI 1.011-1.193 p = 0.027) and PSA (OR 1.074 95% CI 1.014-1.137 p = 0.015) were found to be independent predictors of high grade disease.

CONCLUSIONS

In our cohort of patients, serum levels of SHBG are not predictive of PCa or high grade disease. According to our experience SHBG should not be considered a biomarker in PCa diagnosis neither a marker for high grade disease.

Prostate size and adverse pathologic features in men undergoing radical prostatectomy

OBJECTIVE

To investigate the relationship between prostate volume measured from preoperative imaging and adverse pathologic features at the time of radical prostatectomy and evaluate the potential effect of clinical stage on such relationship.

METHODS

In 1756 men who underwent preoperative magnetic resonance imaging and radical prostatectomy from 2000 to 2010, we examined associations of magnetic resonance imaging-measured prostate volume with pathologic outcomes using univariate logistic regression and with postoperative biochemical recurrence using Cox proportional hazards models. We also analyzed the effects of clinical stage on the relationship between prostate volume and adverse pathologic features via interaction analyses.

RESULTS

In univariate analyses, smaller prostate volume was significantly associated with high pathologic Gleason score (P<.0001), extracapsular extension (P<.0001), and positive surgical margins (P=.032). No significant interaction between clinical stage and prostate volume was observed in predicting adverse pathologic features (all P>.05). The association between prostate volume and recurrence was significant in a multivariable analysis adjusting for postoperative variables (P=.031) but missed statistical significance in the preoperative model (P=.053). Addition of prostate volume did not change C-Indices (0.78 and 0.83) of either model.

CONCLUSION

Although prostate size did not enhance the prediction of recurrence, it is associated with aggressiveness of prostate cancer. There is no evidence that this association differs depending on clinical stage. Prospective studies are warranted assessing the effect of initial method of detection on the relationship between volume and outcome.

DNA damage response and prostate cancer: defects, regulation and therapeutic implications

DNA damage response (DDR) includes the activation of numerous cellular activities that prevent duplication of DNA lesions and maintain genomic integrity, which is critical for the survival of normal and cancer cells. Specific genes involved in the DDR such as BRCA1/2 and P53 are mutated during prostate cancer progression, while various oncogenic signaling such as Akt and c-Myc are activated, enhancing the replication stress and increasing the genomic instability of cancer cells. These events may render prostate cancer cells particularly sensitive to inhibition of specific DDR pathways, such as PARP in homologous recombination (HR) DNA repair and Chk1 in cell cycle checkpoint and DNA repair, creating opportunities for synthetic lethality or synergistic cytotoxicity. Recent reports highlight the critical role of androgen receptor (AR) as a regulator of DDR genes, providing a rationale for combining DNA-damaging agents or targeted DDR inhibitors with hormonal manipulation or AR inhibition as treatment for aggressive disease. The aims of this review are to discuss specific DDR defects in prostate cancer that occur during disease progression, to summarize recent advances in understanding the regulation of DDR in prostate cancer, and to present potential therapeutic opportunities through combinational targeting of the intact components of DDR signaling pathways.

GnRH agonists and the rapidly increasing use of combined androgen blockade in prostate cancer

The discovery of medical castration with GnRH agonists in 1979 rapidly replaced surgical castration and high doses of estrogens for the treatment of prostate cancer. Soon afterwards, it was discovered that androgens were made locally in the prostate from the inactive precursor DHEA of adrenal origin, a mechanism called intracrinology. Taking into account these novel facts, combined androgen blockade (CAB) using a pure antiandrogen combined with castration in order to block the two sources of androgens was first published in 1982. CAB was the first treatment shown in randomized and placebo-controlled trials to prolong life in prostate cancer, even at the metastatic stage. Most importantly, the results recently obtained with the novel pure antiandrogen enzalutamide as well as with abiraterone, an inhibitor of 17α-hydroxylase in castration-resistant prostate cancer, has revitalized the CAB concept. The effects of CAB observed on survival of heavily pretreated patients further demonstrates the importance of the androgens made locally in the prostate and are a strong motivation to apply CAB to efficiently block all sources of androgens earlier at start of treatment and, even better, before metastasis occurs. The future of research in this field thus seems to be centered on the development of more potent blockers of androgens formation and action in order to obtain better results at the metastatic stage and, for the localized stage, reduce the duration of treatment required to achieve complete apoptosis and control of prostate cancer proliferation before it reaches the metastatic or noncurable stage.

The safety of testosterone supplementation therapy in prostate cancer

Patients with prostate cancer can present with hypogonadism and experience health and quality-of-life declines related to low testosterone levels. Despite generations of urological dogma suggesting that testosterone supplementation therapy (TST) for hypogonadism causes prostate-cancer progression, a review of the contemporary literature provides evidence to the contrary. The prostate saturation model suggests that the androgen receptor (AR) is saturated at serum testosterone levels of 150-200 ng/dl, and that additional serum testosterone above this level has limited, if any, effects within the prostate. Indeed, studies in the modern era of PSA assessments indicate that TST does not affect prostate size, intraprostatic testosterone levels, or prostate-cancer progression, provided the baseline serum testosterone level is greater than this AR saturation point. However, the body of data on this subject comes from a small number of cases, and TST should only be administered to patients with prostate cancer after thorough discussions of the risks and benefits, with subsequent careful monitoring.

Systematic Literature Review of the Epidemiology of Nongenetic Forms of Hypogonadism in Adult Males

This study summarizes the literature on the prevalence, incidence, and proportion of patients receiving treatment for male hypogonadism and a systematic literature search was performed for articles published in the last 20 years. Of the 97 studies identified, 96 examined the prevalence, 2 examined the incidence, and 4 examined the proportion of males with hypogonadism patients receiving treatment. Based on studies conducted in Europe and USA, the prevalence of hypogonadism in the general population ranged from 2.1% to 12.8% of middle-aged to older men, with an estimated incidence of 12 new cases per 1,000 person-years. Prevalence was higher among patients with comorbid conditions, such as type 2 diabetes mellitus and obesity. Approximately 10–12% of men with hypogonadism were receiving testosterone treatment. This literature review suggests that there is potentially a significant burden of hypogonadism in the general population. Burden seems to increase with age and in the presence of certain disease conditions. Data suggests that many hypogonadal men who may benefit from testosterone replacement are not receiving treatment. This may be the result of underdiagnosis of the disease, lack of awareness by patients or physicians, irregularities surrounding the diagnostic criteria, and deficiency of long-term safety studies.

Is there an association between serum prostate-specific antigen values and serum testosterone levels in healthy men?

Purpose

To evaluate the relationship between levels of total testosterone and total prostate-specific antigen (PSA) in healthy men with PSA<4 ng/mL.

Materials and Methods

The study comprised 179 men with a mean age of 59.19±12 years who visited Osmaniye State Hospital, Osmaniye, Turkey, between January 2006 and January 2007 for a routine checkup. The patients were divided into two subgroups: patients with PSA<2.5 mg/ml (group I, n=160 patients) and patients with PSA of 2.5 to 4 ng/mL (group II, n=19 patients). The relationship between PSA and testosterone levels was investigated in both groups and in patients aged <60 years. The mean testosterone level was calculated for patients aged <50 years and was compared with the mean value of patients aged ≥50 years.

Results

In all patients, the mean values for serum PSA and total testosterone were 1.27±0.88 ng/mL and 404.04±158.86 ng/mL, respectively. No correlation was detected between serum PSA and testosterone levels in either subgroup (group I, r=0.072, p=0.363; group II, r=0.031, p=0.900) or in patients aged <60 years (r=0.032, p=0.72). The mean values of testosterone in patients aged ≥50 years and in patients aged <50 years were 417.01±163.35 and 344.16±120.21 ng/dL, respectively (p=0.02).

Conclusions

No impact of testosterone was found on the PSA level in healthy men with PSA <4 ng/mL. Therefore, a high serum testosterone level may not mandate adjustment of PSA values. This serum sex hormone showed a significant increment after the age of 50 years. Further studies including a larger number of patients should be carried out to confirm these findings.

A hormone-dependent feedback-loop controls androgen receptor levels by limiting MID1, a novel translation enhancer and promoter of oncogenic signaling

BACKGROUND

High androgen receptor (AR) level in primary tumour predicts increased prostate cancer (PCa)-specific mortality. Furthermore, activations of the AR, PI3K, mTOR, NFκB and Hedgehog (Hh) signaling pathways are involved in the fatal development of castration-resistant prostate cancer during androgen ablation therapy. MID1, a negative regulator of the tumor-suppressor PP2A, is known to promote PI3K, mTOR, NFκB and Hh signaling. Here we investigate the interaction of MID1 and AR.

METHODS

AR and MID1 mRNA and protein levels were measured by qPCR, Western blot and immunohistochemistry. Co-immunoprecipitation followed by PCR and RNA-pull-down followed by Western blot was used to investigate protein-mRNA interaction, chromatin-immunoprecipitation followed by next-generation sequencing for identification of AR chromatin binding sites. AR transcriptional activity and activity of promoter binding sites for AR were analyzed by reporter gene assays. For knockdown or overexpression of proteins of interest prostate cancer cells were transfected with siRNA or expression plasmids, respectively.

RESULTS

The microtubule-associated MID1 protein complex associates with AR mRNA via purine-rich trinucleotide repeats, expansions of which are known to correlate with ataxia and cancer. The level of MID1 directly correlates with the AR protein level in PCa cells. Overexpression of MID1 results in a several fold increase in AR protein and activity without major changes in mRNA-levels, whereas siRNA-triggered knockdown of MID1 mRNA reduces AR-protein levels significantly. Upregulation of AR protein by MID1 occurs via increased translation as no major changes in AR protein stability could be observed. AR on the other hand, regulates MID1 via several functional AR binding sites in the MID1 gene, and, in the presence of androgens, exerts a negative feedback loop on MID1 transcription. Thus, androgen withdrawal increases MID1 and concomitantly AR-protein levels. In line with this, MID1 is significantly over-expressed in PCa in a stage-dependent manner.

CONCLUSION

Promotion of AR, in addition to enhancement of the Akt-, NFκB-, and Hh-pathways by sustained MID1-upregulation during androgen deprivation therapy provides a powerful proliferative scenario for PCa progression into castration resistance. Thus MID1 represents a novel, multi-faceted player in PCa and a promising target to treat castration resistant prostate cancer.

Corpulence is the crucial factor: association of testosterone and/or obesity with prostate cancer stage

OBJECTIVES

To evaluate whether low testosterone levels or obesity, or both, are directly associated with tumor stage/grade in patients with clinically localized prostate cancer.

METHODS

Preoperative androgen serum levels (total and free testosterone), sex hormone-binding globulin, body mass index and waist circumference were assessed in 510 consecutive European Caucasian men treated with radical prostatectomy. Hormone levels and body mass index/waist circumference were correlated with patient- and tumor-specific characteristics using multivariable logistic regression analysis.

RESULTS

Even though we confirmed an inverse correlation between bodyweight and testosterone levels, only overweight - but not low testosterone - was associated with advanced disease and poor differentiation of prostate cancer. Using multivariate analyses, both body mass index ≥30 kg/m(2) and waist circumference >110 cm were associated with high-grade disease (Gleason score ≥8). A waist circumference >110 cm also correlated significantly with lymph node metastasis.

CONCLUSIONS

This is the first study showing that obesity, but not low serum testosterone levels, is significantly associated with high grade and metastatic disease in men diagnosed with clinically localized prostate cancer. The present findings suggest that low androgen levels at diagnosis, which used to be held responsible for the development of aggressive prostate cancer, is only an epiphenomenon of obesity rather than the cause of prostate cancer development and/or progression.

Lifestyle and dietary factors in prostate cancer prevention

The etiology of prostate cancer (PCa) is still largely unknown and the only well-established risk factors are those that are non-modifiable (age, race, and family history). Therefore, the identification of lifestyle and dietary factors which might prevent PCa development and progression is of paramount importance from a public health point of view. Accumulating evidence indicates that obesity may have a dual effect on PCa: an increased risk of aggressive PCa and a decreased risk of localized PCa. Both occupational and leisure time physical activity have been observed to be associated with a reduced PCa risk. Different dietary factors including coffee have been examined in several epidemiological studies, but results have been mostly inconsistent. However, these inconsistencies can be, at least partly, explained by the fact that the majority of those studies examined total PCa risk only and, in addition, they did not take into account the different genetic characteristics within the study populations. Therefore, the future epidemiological studies should focus on the analysis of PCa subtypes separately in order to examine possible etiological heterogeneity of PCa in relation to some exposures. In addition, differences in the genetic characteristics of the study participants should be taken into account to explore the possibility of gene-environment interactions.

Association of body mass index and prostate cancer mortality

OBJECTIVES

Inconsistent evidence exists on whether obesity is associated with an increased risk of prostate cancer death post-radical prostatectomy. We examined data from three large health plans to evaluate if an increased body mass index (BMI) at prostate cancer diagnosis is related to prostate cancer mortality

SUBJECTS AND METHODS

This population-based case-control study included 751 men with prostate cancer who underwent radical prostatectomy. Cases were men who died due to prostate cancer (N=323) and matched controls (N=428). We used multivariable logistic regression models to assess the association between BMI at diagnosis and prostate cancer mortality, adjusted for Gleason score, PSA, tumour characteristics, and matching factors.

RESULTS

Study subjects were classified into the following BMI (kg/m2) categories: healthy (18.5-24.9), overweight (25-29.9) and obese (≥30). Nearly 43% of the participants had a BMI ≥25 at diagnosis. A higher fraction of cases (30%) were obese compared to controls (22%). Overall, obese men had more than a 50% increase in prostate cancer mortality (adjusted odds ratio=1.50 [95% CI, 1.03-2.19]) when compared to men with healthy BMI. After stratifying by Gleason score, the odds of mortality generally rose with increasing BMI. The strongest effect was observed in the Gleason score 8+ category (2.37, 95% CI: 1.11-5.09). These associations persisted after adjusting for PSA at diagnosis and other tumour characteristics.

CONCLUSIONS

These results suggest that BMI at diagnosis is strongly correlated with prostate cancer mortality, and that men with aggressive disease have a markedly greater odds of death if they are overweight or obese.

[Influence of plasmatic testosterone during natural history of prostate cancer: a review]

INTRODUCTION

Prostate cancer (PCa) is the most common disease in male patients and it has the particularity to be androgen dependent. The aim of the current study was to provide an overview about the interest of testosterone dosage during the management of PCa regardless of the stage of the disease. PATIENTS ET METHODS: A systematic review of the literature was done from the PubMed database by searching the following key words alone or in combination: prostate cancer; testosterone; risk; aggressiveness; hormonotherapy; active surveillance; prognosis; androgen; cardiovascular risk; biochemical recurrence.

RESULTS

The level of plasmatic testosterone depends on the moment of the day with a peak between the end of the night and in the morning. We can test either the whole testosterone level, the free testosterone level or the bioavailable testosterone. The bioavailable testosterone is more representative of the presence of androgen in tissues but a specialized laboratory is mandatory. The testosterone plasmatic rate is potentially useful during several steps of the PCa management: in localized prostate cancer cases, men with low testosterone levels are more likely to have an aggressive disease and are therefore not good candidates for active surveillance. An extensive radical prostatectomy should be considered in case of young men since these patients are more likely to recur subsequently; in advanced prostate cancer cases, a testosterone level has to be less or equal to 0.2 ng/mL to guarantee an appropriate castration when a patient is undergoing an androgen deprivation treatment. A dissociation between the trend of PSA and testosterone levels can be the starting point of the castration-resistant period of the disease.

CONCLUSION

The testosterone level can bring useful information regarding the profile of PCa and its ability to evolve during the whole natural history of the disease.

Prediagnostic circulating sex hormones are not associated with mortality for men with prostate cancer

BACKGROUND

Sex hormones play an important role in the growth and development of the prostate, and low androgen levels have been suggested to carry an adverse prognosis for men with prostate cancer (PCa).

OBJECTIVE

To examine the association between prediagnostic circulating sex hormones and lethal PCa in two prospective cohort studies, the Physicians' Health Study (PHS) and the Health Professionals Follow-up Study (HPFS).

DESIGN, SETTING, AND PARTICIPANTS

We included 963 PCa cases (700 HPFS; 263 PHS) that provided prediagnostic blood samples, in 1982 for PHS and in 1993-1995 for HPFS, in which circulating sex hormone levels were assayed.

OUTCOME MEASURES AND STATISTICAL ANALYSIS

The primary end point was lethal PCa (defined as cancer-specific mortality or development of metastases), and we also assessed total mortality through March 2011. We used Cox proportional hazards models to evaluate the association of prediagnostic sex hormone levels with time from diagnosis to development of lethal PCa or total mortality.

RESULTS AND LIMITATIONS

PCa cases were followed for a mean of 12.0±4.9 yr after diagnosis. We confirmed 148 cases of lethal PCa and 421 deaths overall. Using Cox proportional hazard models, we found no significant association between quartile of total testosterone, sex hormone binding globulin (SHBG), SHBG-adjusted testosterone, free testosterone, dihydrotestosterone, androstanediol glucuronide, or estradiol and lethal PCa or total mortality. In subset analyses stratified by Gleason score, TNM stage, age, and interval between blood draw and diagnosis, there was also no consistent association between lethal PCa and sex hormone quartile.

CONCLUSIONS

We found no overall association between prediagnostic circulating sex hormones and lethal PCa or total mortality. Our null results suggest that reverse causation may be responsible in prior studies that noted adverse outcomes for men with low circulating androgens.

Diabetes predicts metastasis after radical prostatectomy in obese men: results from the SEARCH database

OBJECTIVE

To examine the association between diabetes and metastasis risk after radical prostatectomy (RP) and to determine if race or obesity modifies this relationship.

PATIENTS AND METHODS

Patients comprised 2058 US veterans with prostate cancer (PCa) enrolled in the Shared Equal-Access Regional Cancer Hospital (SEARCH) database and treated with RP between 1988 and 2010. The association of diabetes with metastasis risk or secondary treatment rates was examined using Cox proportional hazards, adjusting for preoperative and, separately, clinical and postoperative findings. The effect modification by race (black vs white) and obesity (body mass index [BMI] ≥30 vs <30 kg/m(2) ) was tested via interaction terms.

RESULTS

Men with diabetes had higher BMIs and were more likely to be non-white (all P ≤ 0.001). On multivariable analysis, diabetes was not associated with metastasis risk (P ≥ 0.45), but, among men with diabetes, longer diabetes duration was associated with higher metastasis risk (P ≤ 0.035). When stratified by obesity, diabetes was linked with higher metastasis risk in obese but not in non-obese men (P-interaction ≤ 0.037), but there was no significant interaction with race (P-interaction ≥ 0.56). Diabetes also predicted more aggressive secondary treatment among obese men but less aggressive treatment among non-obese men (hazard ratio 1.39 vs 0.63, P-interaction = 0.006). Where applicable, results were similar for both pre- and postoperative models.

CONCLUSIONS

Diabetes was not associated with metastasis risk overall. Stratification by obesity yielded significant differences, with diabetes linked to a fourfold higher metastasis risk in obese men, despite predicting more aggressive secondary treatment. Longer diabetes duration was also associated with increased metastasis risk.

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.

Relationship of sex steroid hormones with body size and with body composition measured by dual-energy X-ray absorptiometry in US men

PURPOSE

To evaluate the association of body size-captured via whole-body dual-energy X-ray absorptiometry (DXA) and physical measurement-with serum sex steroid hormones and sex hormone binding globulin (SHBG), we utilized cross-sectional data and serum samples from the National Health and Nutrition Examination Survey (NHANES; 1999-2004).

METHODS

Testosterone, androstanediol glucuronide (3-alpha-diol-G), estradiol, and SHBG were measured via immunoassay in serum samples from a total of 898 adult men (ages 20-90) participating in the morning examination. As part of the NHANES data collection, DXA scans and measurements of weight, height, and waist circumference were performed by trained staff. Linear regression was used to estimate associations between body size and hormone levels adjusted for potential confounders and NHANES sampling procedures.

RESULTS

Total bone area (cm(2)) was inversely associated with total testosterone (ng/mL) [beta = -0.12; p value < 0.01], while bone mineral density (g/cm(2)) was inversely associated with SHBG (nmol/L) [beta = -17.16; p value = 0.01]. Increased percent body fat was associated with lower concentrations of total testosterone [beta = -0.16; p value < 0.01] and SHBG [beta = -1.11; p value < 0.01] and higher concentrations of free estradiol (fg/mL) [beta = 12.52; p value < 0.01].

CONCLUSIONS

Clinical measures of body fat (measured via DXA scan) and anthropometric measures of body fat (BMI and waist circumference) provided similar inferences regarding the association between increased body fat and hormone levels in men. Increased body fat was associated with lower circulating levels of testosterone (total and free) and SHBG and higher circulating levels of free estradiol in men, while decreased bone mineral density was associated with higher circulating levels of SHBG.

Androgen receptor GGC polymorphism and testosterone levels associated with high risk of prostate cancer and benign prostatic hyperplasia

Polymorphic GGC repeats in the androgen receptor (AR) gene can alter transactivation of androgen-responsive genes and increase the risk of benign prostatic hyperplasia (BPH) and prostate cancer (PCa). We investigated the association between GGC repeat length, testosterone levels and the risk of developing PCa and BPH in a population from southern Brazil. A sample comprising 130 PCa, 126 BPH and 88 control patients was evaluated. DNA was extracted from leukocytes and the AR gene was analyzed by fragment analysis. The hazard ratio (HR) was estimated. GGC mean length was not different between the three study groups. The risk of developing PCa in individuals with GGC > 19 was 3.300 (95 %CI 1.385-7.874) higher when compared to the GGC ≤ 19 group (p = 0.007). The risk of developing PCa and BPH in individuals with total testosterone levels <4 ng/mL was 2.799 (95 % CI 1.362-5.754). (p = 0.005) and 2.786 (95 % CI 1.470-5.280) (p = 0.002), respectively. Total testosterone levels in patients with GGC > 19 were significantly lower when compared to patients in the GGC ≤ 19 group. Our data suggest that the presence of a high number of polymorphic GGC repeats in the AR gene is associated with an increased risk of developing PCa and BPH, and that lower testosterone levels also increase the risk of developing these diseases.

Influence of opioid consumption on serum prostate-specific antigen levels in men without clinical evidence of prostate cancer

OBJECTIVE

To determine the effect of opioid consumption on the serum prostate-specific antigen (PSA) level.

METHODS

From April 2009 to December 2011, 56 opioid users and 82 age-matched controls participated in the present study. The exclusion criteria were prostate cancer or other malignancies, serum PSA level ≥ 4 ng/dL, abnormal digital rectal examination findings, previous prostate surgery, pelvic radiotherapy, bladder stone, urinary tract infection, recent prostatic manipulation, and a history of taking drugs that alter the serum PSA level. The prostate volume and PSA, serum testosterone, and luteinizing and follicle-stimulating hormone levels were measured in the eligible participants and compared between the opioid users and control subjects. The study was conducted in accordance with the Declaration of Helsinki, and the institutional review board approved the study.

RESULTS

The serum PSA level was significantly lower in opioid users compared with that in the control subjects (0.82 ± 0.77 vs 1.95 ± 1.00, P < .001). The testosterone level was also lower in the opioid users (339.08 ± 142.49 vs 396.71 ± 133.64, P = .008). The difference between the PSA levels remained significant when a comparison was performed between the eugonadal opioid users and eugonadal control subjects. Moreover, the effect of opioid consumption on the PSA level persisted on multivariate analysis, controlling for serum testosterone level.

CONCLUSION

Opium consumption was associated with significant decline in the serum PSA level and warrants adjustment in the PSA cutpoints at which biopsy is recommended. Opioid-induced hypogonadism does not seem to account for the PSA decline, and additional studies are required to determine the involved mechanisms.