Associations of adiponectin and leptin with stage and grade of PSA-detected prostate cancer: the ProtecT study

Circulating adiponectin and leptin and risk of overall and aggressive prostate cancer: a systematic review and meta-analysis

Obesity is associated with an increased risk of advanced, recurrent and fatal prostate cancer. Adipokines may mediate this relationship. We conducted a systematic review and meta-analysis of associations of leptin and adiponectin with overall and aggressive prostate cancer. Bibliographic databases were systematically searched up to 1st April 2017. Log Odds Ratios (ORs) per 2.5 unit increase in adiponectin or leptin levels were derived and pooled. All analyses were stratified by study type (cross-sectional/prospective). 746 papers were retrieved, 34 eligible studies identified, 31 of these could be included in the meta-analysis. Leptin was not consistently associated with overall prostate cancer (pooled OR 1.00, 95%CI 0.98-1.02, per 2.5 ng/ml increase, prospective study OR 0.97, 95%CI 0.95-0.99, cross-sectional study OR 1.19, 95%CI 1.13-1.26) and there was weak evidence of a positive association with aggressive disease (OR 1.03, 95%CI 1.00-1.06). There was also weak evidence of a small inverse association of adiponectin with overall prostate cancer (OR 0.96, 95%CI 0.93-0.99, per 2.5 µg/ml increase), but less evidence of an association with aggressive disease (OR 0.98, 95%CI 0.94-1.01). The magnitude of any effects are small, therefore levels of circulating adiponectin or leptin alone are unlikely to be useful biomarkers of risk or prognosis.

Active monitoring, radical prostatectomy and radical radiotherapy in PSA-detected clinically localised prostate cancer: the ProtecT three-arm RCT

BACKGROUND

Prostate cancer is the most common cancer among men in the UK. Prostate-specific antigen testing followed by biopsy leads to overdetection, overtreatment as well as undertreatment of the disease. Evidence of treatment effectiveness has lacked because of the paucity of randomised controlled trials comparing conventional treatments.

OBJECTIVES

To evaluate the effectiveness of conventional treatments for localised prostate cancer (active monitoring, radical prostatectomy and radical radiotherapy) in men aged 50-69 years.

DESIGN

A prospective, multicentre prostate-specific antigen testing programme followed by a randomised trial of treatment, with a comprehensive cohort follow-up.

SETTING

Prostate-specific antigen testing in primary care and treatment in nine urology departments in the UK.

PARTICIPANTS

Between 2001 and 2009, 228,966 men aged 50-69 years received an invitation to attend an appointment for information about the Prostate testing for cancer and Treatment (ProtecT) study and a prostate-specific antigen test; 82,429 men were tested, 2664 were diagnosed with localised prostate cancer, 1643 agreed to randomisation to active monitoring (n = 545), radical prostatectomy (n = 553) or radical radiotherapy (n = 545) and 997 chose a treatment.

INTERVENTIONS

The interventions were active monitoring, radical prostatectomy and radical radiotherapy.

TRIAL PRIMARY OUTCOME MEASURE

Definite or probable disease-specific mortality at the 10-year median follow-up in randomised participants.

SECONDARY OUTCOME MEASURES

Overall mortality, metastases, disease progression, treatment complications, resource utilisation and patient-reported outcomes.

RESULTS

There were no statistically significant differences between the groups for 17 prostate cancer-specific (p = 0.48) and 169 all-cause (p = 0.87) deaths. Eight men died of prostate cancer in the active monitoring group (1.5 per 1000 person-years, 95% confidence interval 0.7 to 3.0); five died of prostate cancer in the radical prostatectomy group (0.9 per 1000 person-years, 95% confidence interval 0.4 to 2.2 per 1000 person years) and four died of prostate cancer in the radical radiotherapy group (0.7 per 1000 person-years, 95% confidence interval 0.3 to 2.0 per 1000 person years). More men developed metastases in the active monitoring group than in the radical prostatectomy and radical radiotherapy groups: active monitoring, n = 33 (6.3 per 1000 person-years, 95% confidence interval 4.5 to 8.8); radical prostatectomy, n = 13 (2.4 per 1000 person-years, 95% confidence interval 1.4 to 4.2 per 1000 person years); and radical radiotherapy, n = 16 (3.0 per 1000 person-years, 95% confidence interval 1.9 to 4.9 per 1000 person-years; p = 0.004). There were higher rates of disease progression in the active monitoring group than in the radical prostatectomy and radical radiotherapy groups: active monitoring (n = 112; 22.9 per 1000 person-years, 95% confidence interval 19.0 to 27.5 per 1000 person years); radical prostatectomy (n = 46; 8.9 per 1000 person-years, 95% confidence interval 6.7 to 11.9 per 1000 person-years); and radical radiotherapy (n = 46; 9.0 per 1000 person-years, 95% confidence interval 6.7 to 12.0 per 1000 person years; p < 0.001). Radical prostatectomy had the greatest impact on sexual function/urinary continence and remained worse than radical radiotherapy and active monitoring. Radical radiotherapy's impact on sexual function was greatest at 6 months, but recovered somewhat in the majority of participants. Sexual and urinary function gradually declined in the active monitoring group. Bowel function was worse with radical radiotherapy at 6 months, but it recovered with the exception of bloody stools. Urinary voiding and nocturia worsened in the radical radiotherapy group at 6 months but recovered. Condition-specific quality-of-life effects mirrored functional changes. No differences in anxiety/depression or generic or cancer-related quality of life were found. At the National Institute for Health and Care Excellence threshold of £20,000 per quality-adjusted life-year, the probabilities that each arm was the most cost-effective option were 58% (radical radiotherapy), 32% (active monitoring) and 10% (radical prostatectomy).

LIMITATIONS

A single prostate-specific antigen test and transrectal ultrasound biopsies were used. There were very few non-white men in the trial. The majority of men had low- and intermediate-risk disease. Longer follow-up is needed.

CONCLUSIONS

At a median follow-up point of 10 years, prostate cancer-specific mortality was low, irrespective of the assigned treatment. Radical prostatectomy and radical radiotherapy reduced disease progression and metastases, but with side effects. Further work is needed to follow up participants at a median of 15 years.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN20141297.

FUNDING

This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 37. See the National Institute for Health Research Journals Library website for further project information.

Assessment of expression levels of leptin and leptin receptor as potential biomarkers for risk of prostate cancer development and aggressiveness

Background

Prostate cancer (PCa) is one of the most frequently diagnosed cancers worldwide. Despite the growing evidence associating obesity and adipokines, particularly leptin and its receptors, with cancer development and progression, it is still a debatable matter in PCa.

Objectives

We aimed to assess the role of leptin and its receptors as potential biomarkers for the risk of PCa development and aggressiveness.

Methods

In this study, 176 men were included and categorized according to an established histopathological diagnosis into three age‐ and BMI‐matched groups. The PCa group included 56 patients while the BPH group and the control group comprised 60 men each. Serum levels of total PSA (tPSA) were assessed by ELISA and mRNA expression levels of leptin and leptin receptors were assessed by RT‐PCR.

Results

Leptin and leptin receptor mRNA expression levels were significantly higher in PCa patients relative to BPH and to healthy control men. Both were overexpressed in PCa patients with aggressive and distantly metastasizing tumors compared to patients with confined tumors. Leptin receptor mRNA was an independent predictor of high Gleason score ≥ 7, distant metastasis, LN, and seminal vesicles invasion.

Conclusion

Leptin and its receptors are suggested to be potential biomarkers for PCa; leptin receptor mRNA might predict risk and aggressiveness of PCa.

Appetite-regulating hormones-leptin, adiponectin and ghrelin-and the development of prostate cancer: a systematic review and exploratory meta-analysis

BACKGROUND

Obesity has been proposed as a risk factor for prostate cancer (PCa). In obesity, serum levels of the appetite-regulating hormones-leptin, adiponectin, and ghrelin-become deregulated.

OBJECTIVE

To explore whether serum levels of appetite-regulating hormones associate with the incidence of PCa, the incidence of advanced disease, or PCa-specific mortality.

METHODS

PRISMA guidelines were followed. A systematic search for relevant articles published until March 2019 was performed using the databases PubMed, EMBASE, and Web of Science. Observational studies with data on serum levels of leptin, adiponectin, or ghrelin and PCa outcome were included. Meta-analysis was used to combine risk estimates. Meta-relative risks (mRRs) were calculated using random effects models. When available, raw data was pooled. Publication bias was assessed by funnel plot and Begg's test.

RESULTS

Thirty-five studies were eligible for inclusion. The qualitative analysis indicated that leptin was not consistently associated with any PCa outcome, although several cohorts reported decreased adiponectin levels in men who later developed advanced PCa. Based on the meta-analysis, there was no significant effect of leptin on PCa incidence (mRR = 0.93 (95% CI 0.75-1.16), p = 0.52) or advanced PCa (mRR = 0.90 (95% CI 0.74-1.10), p = 0.30). There were insufficient studies to estimate the mRR of PCa incidence for men with the highest levels of adiponectin. The combined risk of advanced PCa for men with the highest levels of adiponectin was reduced but did not reach significance (mRR = 0.81 (95% CI 0.61-1.08), p = 0.15).

CONCLUSIONS

The current evidence does not suggest an association between leptin and PCa outcome. However, there may be an inverse association between adiponectin and the incidence of advanced PCa that should be investigated by further studies. Serum ghrelin has not been largely investigated.

The Adverse Effects of Androgen Deprivation Therapy in Prostate Cancer and the Benefits and Potential Anti-oncogenic Mechanisms of Progressive Resistance Training

Prostate cancer has the second highest incidence of all cancers amongst men worldwide. Androgen deprivation therapy (ADT) remains a common form of treatment. However, in reducing serum testosterone to castrate levels and rendering men hypogonadal, ADT contributes to a myriad of adverse effects which can affect prostate cancer prognosis. Physical activity is currently recommended as synergistic medicine in prostate cancer patients to alleviate the adverse effects of treatment. Progressive resistance training (PRT) is an anabolic exercise modality which may be of benefit in prostate cancer patients given its potency in maintaining and positively adapting skeletal muscle. However, currently, there is a scarcity of RCTs which have evaluated the use of isolated PRT in counteracting the adverse effects of prostate cancer treatment. Moreover, although physical activity in general has been found to reduce relapse rates and improve survival in prostate cancer, the precise anti-oncogenic effects of specific exercise modalities, including PRT, have not been fully established. Thus, the overall objective of this article is to provide a rationale for the in-depth investigation of PRT and its biological effects in men with prostate cancer on ADT. This will be achieved by (1) summarising the metabolic effects of ADT in patients with prostate cancer and its effect on prostate cancer progression and prognosis, (2) reviewing the existing evidence regarding the metabolic benefits of PRT in this cohort, (3) exploring the possible oncological pathways by which PRT can affect prostate cancer prognosis and progression and (4) outlining avenues for future research.

Serum Adipokines as Predictors for the Outcome of Prostate Biopsies at Early Stage Prostate Cancer Diagnosis

Purpose

Elevated adipokines in patients with obesity and metabolic syndrome have been linked to increased risk of prostate cancer (PCa). The association between select serum adipokines and the outcome of prostate biopsies alone and in combination with clinical parameters at different early stages of PCa was investigated.

Patients and methods

Clinical data and serum adipokines were retrieved from three retrospective cohorts representing men at different points in PCa detection: 1. Subjects with no prior biopsies (n=1061), 2. subjects with a prior negative biopsy (REDUCE trial, control arm) (n=1209), 3. subjects with low-risk PCa on active surveillance (AS) (n=154). Adipokines were chosen based on an unpublished pilot study and included: Resistin, Tumor Necrosis Factor-α, Interleukin-6, Monocyte Chemoattractant Protein-1, Hepatocyte Growth Factor, and Nerve Growth Factor. The primary outcome was the absence of PCa on biopsy and the secondary outcome was diagnosis of low-risk PCa fitting the criteria for continuing AS. Logistic regression analysis was used to assess the association of adipokines and negative and/or low-risk PCa at prostate biopsy.

Results

In men with no prior prostate biopsy or with prior negative biopsy, adipokines were not predictors of prostate biopsy outcomes on multivariable regression analysis controlling for known clinical variables. In the AS cohort, MCP-1 and Resistin were significant predictors of biopsy outcome on multivariable analysis (OR 0.20, 95% CI: 0.05–0.85, p= 0.03 & OR 0.30, 95% CI: 0.10 −0.86, p= 0.03).

Conclusion

Our findings do not support a strong role for adipokines for predicting the outcome of prostate biopsies at any early stage in PCa diagnosis.

The association of pathogenic factors of metabolic syndrome on serum prostate-specific antigen levels: a pilot study

Background

Metabolic syndrome (MetS) and serum prostate-specific antigen (PSA) levels are correlated. To investigate the underlying effect of MetS on PSA levels, the relationship between the major pathogenic factors of MetS and serum PSA levels was studied.

Methods

A total of 506 ostensibly healthy men who underwent routine health check-ups were recruited to this study. We evaluated the effect of the major pathogenic factors of MetS, which included insulin resistance, a subclinical inflammatory state and sexual hormone changes, on serum PSA levels by using linear regression analysis and multivariate analysis after adjusting for age, BMI and prostate volume.

Results

When simultaneously adjusting for age, BMI, prostate volume and high-density lipoprotein cholesterol, serum insulin levels and SHBG levels were inversely correlated with serum PSA levels (P = 0.049 and P = 0.004, respectively), and testosterone levels were positively correlated with serum PSA levels (P = 0.039). In multivariate regression models, serum insulin levels and serum SHBG levels were significantly associated with serum PSA levels (both P < 0.001).

Conclusions

Among the major pathogenic factors of metabolic syndrome, insulin resistance and sexual hormone changes may be the most significant contributors to the decline in serum PSA levels.

Role of Adiponectin in prostate cancer

Obesity is defined as a chronic and excessive growth of adipose tissue. It has been associated with a high risk for development and progression of obesity-associated malignancies, while adipokines may mediate this association. Adiponectin is an adipose tissue-derived adipokines, with significant anti-diabetic, anti-inflammatory, anti-atherosclerotic and anti-proliferative properties. Plasma adiponectin levels are decreased in obese individuals, and this feature is closely correlated with development of several metabolic, immunological and neoplastic diseases. Recent studies have shown that prostate cancer patients have lower serum adiponectin levels and decreased expression of adiponectin receptors in tumor tissues, which suggests plasma adiponectin level is a risk factor for prostate cancer. Furthermore, exogenous adiponectin has exhibited therapeutic potential in animal models. In this review, we focus on the potential role of adiponectin and the underlying mechanism of adiponectin in the development and progression of prostate cancer. Exploring the signaling pathways linking adiponectin with tumorigenesis might provide a potential target for therapy.

Circulating Levels of Omentin, Leptin, VEGF, and HGF and Their Clinical Relevance with PSA Marker in Prostate Cancer

Background

Prostate cancer (PCa) is the first in terms of occurrence in Europe and second in Poland. The PCa risk factors include: genetic load, obesity, diet rich in fat, hypertriglyceridemia, and exposure to androgens. The prostate-specific antigen (PSA) level may be elevated in prostate cancer or other prostate disorders. Fat tissue secretes adipocytokines, which increase the risk of cancer development and metastasis.

Objectives

The aims of the study were to investigate the relationship between circulating levels of PSA, adipocytokines: omentin, leptin, hepatocyte growth factor (HGF), and vascular endothelial growth factor (VEGF) in serum obtained from patients with benign prostate hyperplasia (BPH) and prostate cancer (PCa).

Methods

Forty patients diagnosed with BPH and forty diagnosed with PCa were assessed for the purpose of the study. The concentrations of omentin, leptin, HGF, and VEGF were determined using enzyme-linked immunosorbent assays (EIA).

Results

PSA level was significantly higher in the PCa group than in BPH (18.2 versus 9 ng/mL, p < 0.01), while volume of prostate gland was significantly higher in the BPH group than in PCa (39.1 versus 31.1 cm³, p = 0.02). HGF, VEGF, omentin, and leptin concentrations were significantly higher in PCa group than in BPH (359.5 versus 294.9 pg/mL, p = 0.04; 179.3 versus 127.3 pg/mL, p < 0.01; 478.8 versus 408.3 ng/mL, p = 0.01; 15.7 versus 11.2 ng/mL, p = 0.02, resp.). The multiple logistic regression analysis demonstrated that only omentin and PSA levels were independent predictors of PCa in studied subjects.

Conclusions

PSA level as well as the level of omentin may be valuable markers of PCa with clinical significance, when compared to PSA.

Clinical and biochemical markers of visceral adipose tissue activity: Body mass index, visceral adiposity index, leptin, adiponectin, and matrix metalloproteinase-3. Correlation with Gleason patterns 4 and 5 at prostate biopsy

Context:

The correlation between aggressive prostate cancer and obesity mainly based on body mass index (BMI) and pathology after surgery remains controversial.

Aims:

The aim of the study was to correlate BMI, visceral adiposity index (VAI), and the plasmatic levels of leptin, adiponectin, and matrix metalloproteinase-3 (MMP-3), and biomarkers of adipose tissue function, with the detection of Gleason patterns 4 and 5 at biopsy.

Subjects and Methods:

Consecutive patients with prostate cancer at 12-core transrectal biopsy were enrolled. BMI, waist circumference (WC), blood samples to evaluate the plasmatic levels of triglycerides (TG) and high-density lipoproteins (HDL), adiponectin, leptin, and MMP-3 were obtained immediately before biopsy. The VAI was calculated according to the formula: WC/(39.68 + [1.88 × BMI]) × TG/1.03 × 1.31/HDL.

Results:

One hundred and forty-nine patients were entered. The median PSA, BMI, and VAI were 10.0 ng/ml, 27.6 kg/m², and 4.6, respectively. Gleason patterns 4 or 5 were detected in 68 (45.6%) patients; in 15 (41.7%), 31 (44.9%), and 22 (50.0%) among normal weight, overweight, and obese patients, respectively (P = 0.55). The statistical analysis did not show any significant correlation between BMI, VAI, the plasmatic levels of leptin, adiponectin, MMP-3, and the detection of Gleason patterns 4 and 5 at biopsy. A statistically significant association emerged with older age (P = 0.017) and higher PSA values (P = 0.02).

Conclusion:

We did not find any association between BMI, VAI, the plasmatic levels of adiponectin, leptin, and MMP-3 and the detection of Gleason patterns 4 and 5 at prostate biopsy.

Does obesity modify prostate cancer detection in a European cohort?

INTRODUCTION

To investigate prostate-specific antigen (PSA) accuracy and digital rectal examination (DRE) accuracy in detecting prostate cancer according to body mass index (BMI) in Spanish men with an indication of the first prostate biopsy.

MATERIAL AND METHODS

We reviewed the clinical and histopathological data of 1,319 patients who underwent transrectal ultrasound-guided prostate needle biopsy. The patients were categorised according to the BMI as follows: <25 kg/m² (normal weight); 25-29.9 kg/m² (overweight); and ≥30 kg/m² (obese). Receiver operator characteristic curves were used to assess PSA accuracy and DRE accuracy by calculating the area under the curve.

RESULTS

The obesity rate of the cohort was 14%. PSA accuracy for predicting prostate cancer in each BMI category was 0.52, 0.58 and 0.62, respectively (p = 0.01). After stratification by DRE findings, there was no difference in the performance accuracy of PSA in predicting the presence of cancer across BMI groups in abnormal DRE (p = 0.90). Serum PSA, DRE and BMI were strong predictors of prostate cancer diagnosis (odds ratio 1.07, 2.02 and 1.4, respectively; p <0.001). When the DRE was abnormal, a BMI ≥30 increased the risk of prostate cancer twice. With the addition of BMI to the model, the area under the curve of the combined PSA and DRE for diagnosing prostate cancer improved from 0.60 to 0.63.

CONCLUSIONS

The predictive value of PSA in predicting prostate cancer is not poorer in the obese population and the predictive value of an abnormal DRE in cancer detection is significantly modified by the patient's BMI.

Elevated C-Peptides, Abdominal Obesity, and Abnormal Adipokine Profile are Associated With Higher Gleason Scores in Prostate Cancer

BACKGROUND

Prostate cancer development is associated with numerous lifestyle factors (i.e., physical activity, nutrition intake) and metabolic perturbations. These factors have been studied independently; here, we used an integrative approach to characterize these lifestyle and metabolic parameters in men undergoing diagnostic prostate biopsies.

METHODS

We prospectively evaluated 51 consecutive men for body composition, metabolic factors including glucose- and lipid-related measures, as well as lifestyle factors prior to prostate biopsy. Evaluations were performed in a blinded manner and were subsequently related to biopsy outcomes for: (i) presence or absence of cancer; and (ii) where cancer was present, Gleason score.

RESULTS

Serum C-peptide concentrations were significantly greater in participants with Gleason scores ≥4 + 3 (2.8 ± 1.1 ng/ml) compared to those with Gleason 3 + 3 (1.4 ± 0.6 ng/ml) or Gleason 3 + 4 (1.3 ± 0.8 ng/ml, P = 0.002), suggesting greater insulin secretion despite lack of differences in fasting glucose concentrations. Central adiposity, measured by waist circumference, was significantly greater in participants with Gleason ≥4 + 3 (110.1 ± 7.4 cm) compared to those with Gleason 3 + 4 (102.0 ± 9.5 cm, P = 0.028). Men with Gleason ≥4 + 3 also had significantly greater leptin concentrations than those with lower Gleason scores (Gleason ≥4 + 3: 15.6 ± 3.3 ng/ml vs. Gleason 3 + 4: 8.1 ± 8.1 ng/ml, P < 0.05) and leptin:adiponectin ratio (Gleason ≥4 + 3: 9.7 ± 6.1 AU, Gleason 3 + 4: 2.9 ± 3.2, Gleason 3 + 3: 2.4 ± 2.1 AU, P = 0.013).

CONCLUSIONS

We profiled a cluster of obesity-related metabolic perturbations (C-peptide, central adiposity, leptin, and leptin:adiponectin ratios) which may associate with more aggressive prostate cancer histology. Prostate 77:211-221, 2017. © 2016 Wiley Periodicals, Inc.

Association of Obesity-Related Metabolic Disruptions With Cancer Risk and Outcome

Over the past 40 years, the prevalence of obesity has increased epidemically worldwide, which raises significant concerns regarding public health and the associated economic burden. Obesity is a major risk factor for several conditions including cardiovascular disease and type 2 diabetes, and recent evidence suggests that obesity negatively affects cancer risk and outcome. The relationship between obesity and cancer is complex and involves multiple factors both at the systemic and cellular level. Indeed, disruptions in insulin metabolism, adipokines, inflammation, and sex hormones all contribute to the adverse effects of obesity in cancer development and progression. The focus of this review will be the impact of these systemic obesity-related factors on cancer biology, incidence, and outcome. Potential therapeutic interventions and current clinical trials targeting obesity and its associated factors will also be discussed.

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.

Evolving role of adiponectin in cancer-controversies and update

Adiponectin (APN), an adipokine produced by adipocytes, has been shown to have a critical role in the pathogenesis of obesity-associated malignancies. Through its receptor interactions, APN may exert its anti-carcinogenic effects including regulating cell survival, apoptosis and metastasis via a plethora of signalling pathways. Despite the strong evidence supporting this notion, some work may indicate otherwise. Our review addresses all controversies critically. On the whole, hypoadiponectinaemia is associated with increased risk of several malignancies and poor prognosis. In addition, various genetic polymorphisms may predispose individuals to increased risk of obesity-associated malignancies. We also provide an updated summary on therapeutic interventions to increase APN levels that are of key interest in this field. To date efforts to manipulate APN levels have been promising, but much work remains to be done.

Serum adiponectin concentration in 2,939 Japanese men undergoing screening for prostate cancer

Background

Recent investigations suggest that serum adiponectin levels are negatively associated with the development of aggressive prostate cancer, however, not all epigenetic studies support the inverse association.

Methods

We analyzed serum adiponectin levels, prostate-specific antigen (PSA) levels, and outcomes of prostate cancer screening of 2,939 participants of a PSA-based screening program conducted by a single institute in Japan.

Results

The median body mass index (BMI) of the participants was 23.9 kg/m², and 31% had a BMI ≥ 25 kg/m². The adiponectin levels were significantly and negatively correlated with BMI (r =  −0.260, P < 0.0001). However, a significant and positive correlation was observed between adiponectin levels and PSA levels (r = 0.054, P = 0.0061). After screening, 24 (0.82%) patients were diagnosed with prostate cancer. Interestingly, the adiponectin levels of the 24 prostate cancer patients (average 9.86 μg/mL) were significantly higher than those of the 2,817 participants with PSA levels < 4 ng/mL (average 7.63 μg/mL) (P = 0.0049). However, when restricted to the eight high-risk prostate cancer patients, the adiponectin levels did not differ from those of the participants with PSA levels < 4 ng/mL. The age-adjusted cancer detection rate of the participants was calculated by stratifying the BMI (cut-off level 25 kg/m²) and adiponectin levels (cut-off level 6.7 μg/mL). The cancer detection rate in the high-BMI and high-adiponectin group was 1.67%, which was the highest among all groups.

Conclusions

There was a significant positive correlation between adiponectin levels and PSA levels. The present findings also suggest that the incidence of low- or intermediate-risk prostate cancer might be increased in overweight men with high serum adiponectin levels.

The association between metabolic syndrome and prostate cancer: Effect on its aggressiveness and progression

OBJECTIVES

To evaluate the impact of metabolic syndrome and its individual components on prostate biopsy findings, the radical prostatectomy specimen and on biochemical recurrence.

MATERIAL AND METHODS

An observational study was conducted of 1319 men who underwent prostate biopsy between January 2007 and December 2011. The impact on the biopsy findings, the radical prostatectomy specimen and biochemical recurrence was evaluated using logistic regression and Cox regression.

RESULTS

Of the 1319 patients, 275 (21%) had metabolic syndrome, and 517 prostate cancers were diagnosed. A greater percentage of metabolic syndrome was found among patients with prostate cancer than among patients without prostate cancer (25% vs. 18%; P=.002). Poorer results were found in the radical prostatectomy specimens (Gleason score ≥ 7, P<.001; stage ≥ T2c, P<.001; positive surgical margins, P<.001), and there was a greater percentage of biochemical recurrence in patients with metabolic syndrome than in those without metabolic syndrome (24% vs. 13%; P=.003). Metabolic syndrome behaved as an independent predictive factor of finding a Gleason score ≥ 7 for the specimen, as well as for finding a specimen stage ≥ T2c. Metabolic syndrome was also able to independently predict a greater rate of biochemical recurrence (OR: 3.6, P<.001; OR: 3.2, P=.03; HR: 1.7; respectively).

CONCLUSIONS

Metabolic syndrome is associated with poorer findings in the radical prostatectomy specimens and is an independent prognostic factor of biochemical recurrence.

Association of C-peptide and leptin with prostate cancer incidence in the Health Professionals Follow-up Study

PURPOSE

Hyperinsulinemia is hypothesized to influence prostate cancer risk. Thus, we evaluated the association of circulating C-peptide, which is a marker of insulin secretion, and leptin, which is secreted in response to insulin and influences insulin sensitivity, with prostate cancer risk.

METHODS

We identified prostate cancer cases (n = 1,314) diagnosed a mean of 5.4 years after blood draw and matched controls (n = 1,314) in the Health Professionals Follow-up Study. Plasma C-peptide and leptin concentrations were measured by ELISA. Odds ratios (ORs) and 95 % confidence intervals (CI) were estimated taking into account the matching factors age and history of a PSA test before blood draw and further adjusting for body mass index, diabetes, and other factors.

RESULTS

Neither C-peptide (quartile [Q]4 vs. Q1: OR 1.05, 95 % CI 0.82-1.34, p-trend = 0.95) nor leptin (Q4 vs. Q1: OR 0.85, 95 % CI 0.65-1.12, p-trend = 0.14) was associated with prostate cancer risk. Further, neither was associated with risk of advanced or lethal disease (n = 156 cases; C-peptide: Q4 vs. Q1, OR 1.18, 95 % CI 0.69-2.03, p-trend = 0.78; leptin: Q4 vs. Q1, OR 0.74, 95 % CI 0.41-1.36, p-trend = 0.34).

CONCLUSIONS

In this large prospective study, circulating C-peptide and leptin concentrations were not clearly associated with risk of prostate cancer overall or aggressive disease. Well into the PSA era, our findings do not appear to be supportive of the hypothesis that hyperinsulinemia influences risk of total or aggressive prostate cancer.

The diagnostic value of adiponectin multimers in healthy men undergoing screening for prostate cancer

BACKGROUND

Adiponectin has been reported to have a prohibitory effect on prostate cancer. The goal of this study was to evaluate the diagnostic value of adiponectin multimers for prostate cancer.

METHODS

Total adiponectin, high- and low-molecular-weight (HMW, LMW), ratios of these measures, and body mass index (BMI) were compared in a prospective prostate cancer-screened cohort. Multivariable logistic regression was used to assess the association between adiponectin measures, their interaction with BMI, and risk of prostate cancer and Gleason score upgrading from biopsy to prostatectomy.

RESULTS

A total of 228 prostate cancer cases and 239 controls were analyzed: 72 (31.6%) of the cancer cases were high grade (Gleason grade ≥7). Only percent HMW had a statistically significant relationship with prostate cancer (P = 0.04). Among normal and overweight men, the risk of prostate cancer increased as percent HMW increased [OR = 1.24 for a doubling of percent HMW, 95% confidence interval (CI), 0.41-3.75 and OR = 1.81; 95% CI, 1.02-3.20, respectively], whereas among obese men, the risk of prostate cancer decreased (OR = 0.62; 95% CI, 0.32-1.18). Among 97 patients who underwent radical prostatectomy, there was no association between Gleason score upgrading and any of the adiponectin multimers.

CONCLUSION

This study was unable to confirm the utility of total adiponectin as a biomarker for prostate cancer risk. For the adiponectin multimers, only HMW showed increases with prostate cancer but not in all weight classes.

IMPACT

Although adiponectin may play a role in the pathogenesis of prostate cancer, our results do not support adiponectin multimers as biomarkers of detection.

A study of caloric restriction versus standard diet in overweight men with newly diagnosed prostate cancer: a randomized controlled trial

INTRODUCTION

Obese men have an increased risk of prostate cancer (PCa)-specific mortality. Potential mechanisms include insulin and related proteins. We investigate whether a short-term caloric restriction diet in overweight/obese men with newly diagnosed PCa can lead to measurable changes in patient anthropometrics and insulin-related proteins.

METHODS

Overweight and obese PCa patients choosing active surveillance or radical prostatectomy were randomized to a 6-week, caloric-restricted diet or to continue their current diet. Changes from baseline to end of study in anthropometrics, dietary constituents and serum proteins (insulin, c-peptide, IGF-1, adiponectin, IGF-BP3) were compared between the intervention and control groups using a Generalized Estimating Equation model.

RESULTS

Nineteen patients were randomized to the intervention (N = 10) or control (N = 9) group. Men in the intervention group had a 1.7% (3.7 lbs) mean decline in weight versus 1.0% (2.0 lbs) in controls (P < 0.05), and a reduced intake of calories, total and saturated fat, protein and starch (all P < 0.1 compared to controls). There was a significant difference (P = 0.002) in mean serum IGFBP-3 between the intervention (+2.8%) and control group (-6.9%). Other biomarkers changed with the diet intervention to a degree similar to previous weight loss studies but were not statistically significant compared with controls.

CONCLUSION

In this small pilot study, a 6-week caloric restricted diet in men with newly diagnosed PCa produced changes in weight, diet and serum proteins possibly related to prognosis. These results support larger-scale trials testing longer-term weight loss effects on potential PCa progression biomarkers.