Presence of the metabolic syndrome is associated with shorter time to castration-resistant prostate cancer

Effect of BMI and hemoglobin A1c on survival of veterans with metastatic castration-resistant prostate cancer treated with abiraterone or enzalutamide

BACKGROUND

Abiraterone acetate and enzalutamide are two common therapies for metastatic castration-resistant prostate cancer (mCRPC) that have shown improved overall survival (OS). The drugs have different mechanisms of action with limited comparative trials to evaluate treatment in patients with comorbidities such as obesity and diabetes. This is important since abiraterone requires the co-administration of prednisone. We assessed the relationship between body mass index (BMI), hemoglobin A1c (HbA1c), treatment, and survival in mCRPC.

METHODS

Veterans treated with abiraterone or enzalutamide within the Veterans Health Administration between September 10, 2014 and June 2, 2017 with BMI and HbA1c were identified. Additional variables included age, baseline prostate-specific antigen at first treatment for mCRPC, race, and the Charlson comorbidity index. Differences in survival were compared using the Kaplan-Meier method. Cox proportional hazards regression modeling was used to assess the association between initial treatment, BMI, and HbA1c while adjusting for confounding variables.

RESULTS

A total of 5231 patients were identified with a mean age of 75.2 years and 1241 (23.7%) were of black race. BMI was associated with OS with longest median survival of 29.8 months in BMI ≥ 30 (n = 1903), 23.9 months in BMI 25-30 (n = 1879), 15.9 months in BMI 18.5-25 (n = 1336), and 9.2 months in BMI < 18.5 (n = 113, p < 0.001). In a multivariable model compared to normal BMI, increased mortality was observed in BMI < 18.5 (adjusted hazard ratio (aHR) = 1.583, 95% confidence interval [CI]: 1.29-1.94) and a decreased mortality in BMI 25-30 (aHR = 0.751, 95% CI: 0.69-0.81) and BMI > 30 (aHR = 0.644, 95% CI: 0.59-0.70). In 3761 patients with BMI > 25, there was longer OS in patients treated with enzalutamide (28.4 months, n = 1615) compared to abiraterone (25.8 months, n = 2146, p = 0.002). In 1470 patients with BMI < 25, there was no difference in OS between patients treated with enzalutamide (16.0 months, n = 597, p = 0.513) or abiraterone (16.1 months, n = 873). In 1333 veterans with HbA1c ≥ 6.5%, initial prescription of enzalutamide was associated with longer OS compared with abiraterone (24.4 vs. 20.5 months, p = 0.0005). In 2088 patients with HbA1c < 6.5%, there was no difference in OS in patients who were initially prescribed enzalutamide versus abiraterone (25.7 vs. 23.5 months, p = 0.334).

CONCLUSIONS

In veterans with mCRPC, increased BMI was associated with longer survival. Veterans with BMI > 25 had longer survival with enzalutamide compared to abiraterone. In patients with HbA1c ≥ 6.5%, enzalutamide was associated with longer survival compared to abiraterone. These results may facilitate prognostication of survival and improve treatment selection based on patient comorbidities.

Cancer-associated fibroblast-secreted glucosamine alters the androgen biosynthesis program in prostate cancer via HSD3B1 upregulation

After androgen deprivation, prostate cancer frequently becomes castration resistant (CRPC), with intratumoral androgen production from extragonadal precursors that activate the androgen receptor pathway. 3β-Hydroxysteroid dehydrogenase-1 (3βHSD1) is the rate-limiting enzyme for extragonadal androgen synthesis, which together lead to CRPC. Here, we show that cancer-associated fibroblasts (CAFs) increased epithelial 3βHSD1 expression, induced androgen synthesis, activated the androgen receptor, and induced CRPC. Unbiased metabolomics revealed that CAF-secreted glucosamine specifically induced 3βHSD1. CAFs induced higher GlcNAcylation in cancer cells and elevated expression of the transcription factor Elk1, which induced higher 3βHSD1 expression and activity. Elk1 genetic ablation in cancer epithelial cells suppressed CAF-induced androgen biosynthesis in vivo. In patient samples, multiplex fluorescent imaging showed that tumor cells expressed more 3βHSD1 and Elk1 in CAF-enriched areas compared with CAF-deficient areas. Our findings suggest that CAF-secreted glucosamine increases GlcNAcylation in prostate cancer cells, promoting Elk1-induced HSD3B1 transcription, which upregulates de novo intratumoral androgen synthesis to overcome castration.

Targeting lipid metabolism in metastatic prostate cancer

Despite key advances in the treatment of prostate cancer (PCa), a proportion of men have de novo resistance, and all will develop resistance to current therapeutics over time. Aberrant lipid metabolism has long been associated with prostate carcinogenesis and progression, but more recently there has been an explosion of preclinical and clinical data which is informing new clinical trials. This review explores the epidemiological links between obesity and metabolic syndrome and PCa, the evidence for altered circulating lipids in PCa and their potential role as biomarkers, as well as novel therapeutic strategies for targeting lipids in men with PCa, including therapies widely used in cardiovascular disease such as statins, metformin and lifestyle modification, as well as novel targeted agents such as sphingosine kinase inhibitors, DES1 inhibitors and agents targeting FASN and beta oxidation.

Novel plasma exosome biomarkers for prostate cancer progression in co-morbid metabolic disease

Comorbid Type 2 diabetes (T2D), a metabolic complication of obesity, associates with worse cancer outcomes for prostate, breast, head and neck, colorectal and several other solid tumors. However, the molecular mechanisms remain poorly understood. Emerging evidence shows that exosomes carry miRNAs in blood that encode the metabolic status of originating tissues and deliver their cargo to target tissues to modulate expression of critical genes. Exosomal communication potentially connects abnormal metabolism to cancer progression. Here, we hypothesized that T2D plasma exosomes induce epithelial-mesenchymal transition (EMT) and immune checkpoints in prostate cancer cells. We demonstrate that plasma exosomes from subjects with T2D induce EMT features in prostate cancer cells and upregulate the checkpoint genes CD274 and CD155. We demonstrate that specific exosomal miRNAs that are differentially abundant in plasma of T2D adults compared to nondiabetic controls (miR374a-5p, miR-93-5p and let-7b-3p) are delivered to cancer cells, thereby regulating critical target genes. We build on our previous reports showing BRD4 controls migration and dissemination of castration-resistant prostate cancer, and transcription of key EMT genes, to show that T2D exosomes require BRD4 to drive EMT and immune ligand expression. We validate our findings with gene set enrichment analysis of human prostate tumor tissue in TGCA genomic data. These results suggest novel, non-invasive approaches to evaluate and potentially block progression of prostate and other cancers in patients with comorbid T2D.

Association between baseline body mass index and survival in men with metastatic hormone-sensitive prostate cancer: ECOG-ACRIN CHAARTED E3805

BACKGROUND

E3805 (CHAARTED) is a phase 3 trial demonstrating improved survival for men with metastatic hormone-sensitive prostate cancer (mHSPC) randomized to treatment with docetaxel (D) and androgen-deprivation therapy (ADT) versus ADT alone. We assessed the association of baseline body mass index (BMI) and metformin exposure with quality of life (QOL) and prostate cancer outcomes including survival in patients enrolled in the CHAARTED study.

METHODS

We performed a posthoc exploratory analysis of the CHAARTED trial of men with mHSPC randomized to treatment with ADT with or without D between 2006 and 2012. Cox proportional hazards models and Kruskal-Wallis test were used to evaluate the association between BMI with QOL and prostate cancer outcomes and between metformin exposure and survival.

RESULTS

In 788 of 790 enrolled patients with prospectively recorded baseline BMI and metformin exposure status, lower BMI was not associated with survival, but was associated with high volume disease (p < 0.0001) and poorer baseline QOL on functional assessment of cancer therapy-prostate (p = 0.008). Only 68 patients had prevalent metformin exposure at baseline in the CHAARTED trial. Four groups were identified: ADT + D + metformin (n = 39); ADT + D (n = 357); ADT + metformin (n = 29); and ADT alone (n = 363). Baseline clinicopathologic characteristics were similar between groups. In this small exploratory multivariable analysis, metformin exposure was not associated with survival (hazard ratio: 1.15; 95% confidence interval: 0.81-1.63, p = 0.44).

CONCLUSIONS

There was no link between baseline BMI and survival, but lower baseline BMI was associated with features of greater cancer burden and poorer QOL.

Combined impact of lipidomic and genetic aberrations on clinical outcomes in metastatic castration-resistant prostate cancer

BACKGROUND

Both changes in circulating lipids represented by a validated poor prognostic 3-lipid signature (3LS) and somatic tumour genetic aberrations are individually associated with worse clinical outcomes in men with metastatic castration-resistant prostate cancer (mCRPC). A key question is how the lipid environment and the cancer genome are interrelated in order to exploit this therapeutically. We assessed the association between the poor prognostic 3-lipid signature (3LS), somatic genetic aberrations and clinical outcomes in mCRPC.

METHODS

We performed plasma lipidomic analysis and cell-free DNA (cfDNA) sequencing on 106 men with mCRPC commencing docetaxel, cabazitaxel, abiraterone or enzalutamide (discovery cohort) and 94 men with mCRPC commencing docetaxel (validation cohort). Differences in lipid levels between men ± somatic genetic aberrations were assessed with t-tests. Associations between the 3LS and genetic aberrations with overall survival (OS) were examined using Kaplan-Meier methods and Cox proportional hazard models.

RESULTS

The 3LS was associated with shorter OS in the discovery (hazard ratio [HR] 2.15, 95% confidence interval [CI] 1.4-3.3, p < 0.001) and validation cohorts (HR 2.32, 95% CI 1.59-3.38, p < 0.001). Elevated plasma sphingolipids were associated with AR, TP53, RB1 and PI3K aberrations (p < 0.05). Men with both the 3LS and aberrations in AR, TP53, RB1 or PI3K had shorter OS than men with neither in both cohorts (p ≤ 0.001). The presence of 3LS and/or genetic aberration was independently associated with shorter OS for men with AR, TP53, RB1 and PI3K aberrations (p < 0.02). Furthermore, aggressive-variant prostate cancer (AVPC), defined as 2 or more aberrations in TP53, RB1 and/or PTEN, was associated with elevated sphingolipids. The combination of AVPC and 3LS predicted for a median survival of ~12 months. The relatively small sample size of the cohorts limits clinical applicability and warrants future studies.

CONCLUSIONS

Elevated circulating sphingolipids were associated with AR, TP53, RB1, PI3K and AVPC aberrations in mCRPC, and the combination of lipid and genetic abnormalities conferred a worse prognosis. These findings suggest that certain genotypes in mCRPC may benefit from metabolic therapies.

Metabolic syndrome and its pharmacologic treatment are associated with the time to castration-resistant prostate cancer

BACKGROUND

Metabolic syndrome and its pharmacologic treatment can potentially influence the progression of prostate cancer in men receiving androgen deprivation therapy (ADT). We aimed to evaluate the association between metabolic syndrome and its pharmacologic treatment with time to castration-resistant prostate cancer (CRPC).

METHODS

We identified 409 men with metastatic castration-sensitive prostate cancer receiving first line ADT from 1996 to 2014 at our institution. Information concerning metabolic syndrome, statin use, aspirin use, and metformin use at initiation of ADT was collected from medical records. Time to CRPC was defined as the duration between initiating ADT and diagnosis of CRPC based on the Prostate Cancer Working Group 3 definition. Flexible parametric survival models were used to calculate hazard ratios (HR, and 95% confidence intervals, CI) of the association between metabolic conditions and time from ADT initiation to CRPC.

RESULTS

During a median follow-up of 59 months, 87% (N = 356) men progressed to CRPC. Median time to CRPC was 19 months. Fifty-six percent of men met the definition of metabolic syndrome. Controlling for demographic and prostate cancer-specific variables, metabolic syndrome was associated with shorter time to CRPC (HR 1.41, 95% CI 1.09-1.81). Importantly, in men with metabolic syndrome, statin use was associated with a slower progression to CRPC (HR 0.70, 95% CI 0.49-0.98).

CONCLUSIONS

Our study suggests that metabolic syndrome is a risk factor for earlier progression from castration-sensitive to castration-resistant prostate cancer and raises the possibility that treatment, such as statin use, may slow the time to progression.

Exercise oncology: an emerging discipline in the cancer care continuum

Exercise is an essential component of healthy living and well-being. While there is a global acceptance of the benefits of exercise for the general population, there exists hesitancy and confusion among health-care professionals, particularly oncologists, as to whether these benefits translate to cancer patients. Patient referrals to accessible, structured exercise programs in this setting are often overlooked by physicians when formulating a cancer management plan. There is however increasing awareness and acceptance of cancer survivorship as a part of the cancer care continuum, identifying multiple factors that contribute to well-being beyond just cancer outcomes. Efforts to optimize cancer survivorship have stimulated further academic interest in the benefits of healthy living and particularly exercise oncology. There is now compelling evidence that exercise, which includes daily activities such as walking, as well as structured programs, improves multiple-cancer outcomes such as fatigue, quality of life and likely survival, and warrants consideration in the multidisciplinary care of cancer patients. International guidelines have been established that recommend counseling cancer patients with regard to healthy lifestyle changes including exercise. However, there still remains a reluctance from oncology physicians to prescribe exercise for these patients, largely due to uncertainty with regard to their patients' ability to tolerate such an intervention, coupled with insufficient understanding of the potential benefits of these programs. There also exist patient barriers and attitudes that must be overcome. Exercise strategies and bespoke programs that are tailored to the unique abilities and goals of the patients will enhance participation. To move the field forward and integrate exercise oncology into standard practice, it is imperative to raise awareness of the benefits of exercise to cancer patients and their health-care providers. This will facilitate the prescription of exercise as part of the multimodal treatment plan with the ultimate aim of promoting an active lifestyle to optimize patient care and well-being.

The effect of medical and urologic disorders on the survival of patients with metastatic castration resistant prostate cancer treated with abiraterone or enzalutamide

Introduction:

Androgenic deprivation therapies have been linked to the development of metabolic syndrome (MS) and cardiovascular diseases, which may lead to a poorer survival in patients with metastatic Castration-Resistant Prostate Cancer (mCRPC). We aimed to analyze whether some cardiovascular or neurological disorders, together with other medical and urological complications, may have an effect on survival outcomes, at baseline and during treatment from patients treated with androgen pathway inhibitors (API).

Material and Methods:

A retrospective study of a consecutive series of patients diagnosed with mCRPC between 2010 and 2018 treated with API in the first line setting in a single center.

Results:

Seventy-three patients met the inclusion criteria. Baseline prognostic factors associated with worse survival were diabetes mellitus (DM) with insulin needs compared to patients without DM [hazard ratio (HR) = 0.19, p = 0.025], hypertension (HTN) (HR = 0.46, p = 0.035), and a history of stroke (HR = 0.16, p < 0.001). However, previous history of hypercholesterolemia, arrythmias, and cognitive disorders did not result in a significant worsening on survival. During treatment, patients who developed de novo HTN had the best progression free survival (PFS) (HR = 0.38, p = 0.048) and overall survival (OS) (HR 0.08, p = 0.012) compared with patients with previous HTN. Other factors related to worse outcomes included the presence of heart failure (HR = 0.31, p = 0.001), the requirement for major opioids for pain relief (HR = 0.33, p = 0.023), and the presence of bilateral ureterohydronephrosis (HR = 0.12, p = 0.008).

Conclusions:

Some comorbidities may be strongly involved in patient outcomes when receiving API for mCRPC. In this sense, collaborative networking between specialists and caregivers treating prostate cancer (PC) patients should be recommended, focusing on MS features, cardiovascular and neurological disorders in order to anticipate medical and surgical complications.

Why exercise has a crucial role in cancer prevention, risk reduction and improved outcomes

INTRODUCTION

Exercise is one of several factors known to lower the risk of developing cancer, as well as improve outcomes in patients already diagnosed. People who exercise after cancer have lower rates of cancer complications, treatment toxicities, relapse and improved survival. This review highlights the supportive data and biochemical processes, which explain these potential benefits.

SOURCES OF DATA

PubMed, Embase, Medline and Cochrane libraries were searched for papers which addressed the effects of exercise and physical activity on cancer for this review. The search terms used were physical activity, exercise and cancer up to February 2021. We also referred to the background research required for international exercise intervention study involving men with prostate cancer (INTERVAL-GAP4) and scrutinized references within the robust papers published on this subject to ensure we did not miss any clinically studies. One hundred and eighty eight papers were included.

AREAS OF AGREEMENT

Exercise programmes mitigate many of the complications and risks associated with cancer, particularly thromboembolism, fatigue, weight gain, arthralgia, cognitive impairment and depression.

AREAS OF CONTROVERSY

Molecular and biomarker changes, resulting from exercise, suggest that exercise elicits beneficial changes in insulin-related pathways, down-regulates inflammation and serum oestrogen levels, and enhances oxidative, immune and cellular repair pathways. Nonetheless, the evidence remains preliminary.

GROWING POINTS

The timing, intensity and challenges of prehabilitation, adjunct and rehabilitation exercise programmes are being increasingly understood but their implementation remains sporadic.

AREAS FOR DEVELOPING RESEARCH

More robust clinical trial data are needed to substantiate a causal effect of exercise on overall and cancer-specific survival. These studies are ongoing. Research evaluating the most cost-efficient ways of incorporating prehabilitation, adjunct and rehabilitation programmes into routine practice would be helpful to funding bodies and health care strategists.

Effectiveness and Distribution of Testosterone Levels within First Year of Androgen Deprivation Therapy in a Real-World Setting: Results from the Non-Interventional German Cohort LEAN Study

BACKGROUND

Observational studies generate information on real-world therapy and complement data from prospective randomized trials. LEAN is an open-label, non-interventional, multi-centre, German cohort study on leuprorelin in routine clinical practice.

OBJECTIVES

To extend knowledge on the use, effectiveness, and tolerability of HEXAL/Sandoz leuprorelin (in this article, the term Leuprone® HEXAL® covers Leuprorelin Sandoz® as well) solid implant in patients with prostate cancer (PCa) in a real-world setting.

METHODS

959 PCa patients scheduled for androgen deprivation therapy (ADT) received leuprorelin acetate implant. Metabolism, serum prostate-specific antigen (PSA), and testosterone data, if available, were collected at baseline and follow-up visits for ≥12 months.

RESULTS

Of 694 patients in the modified full analysis set, 26.4% received GnRH analogues ≤6 months before enrolment. Fifty-one percent of patients were treated for locally advanced or metastatic PCa. In 19.6% of patients, ADT was used in neoadjuvant or adjuvant settings and in 28.5% with rising PSA after definite therapy. Testosterone levels <0.5 ng/mL were achieved in >90% of patients. Safety profile was in line with the summary of product characteristics. Therapy was well tolerated, with patient-triggered therapy discontinuation in 3.6%.

CONCLUSIONS

This interim analysis confirmed previous efficacy findings for leuprorelin implant in a real-world setting. This contemporary cohort showed a shift in the use of ADT to non-metastatic PCa stages.

Endocrinology of the Aging Prostate: Current Concepts

Benign prostate hyperplasia (BPH), one of the most common diseases in older men, adversely affects quality-of-life due to the presence of low urinary tract symptoms (LUTS). Numerous data support the presence of an association between BPH-related LUTS (BPH-LUTS) and metabolic syndrome (MetS). Whether hormonal changes occurring in MetS play a role in the pathogenesis of BPH-LUTS is a debated issue. Therefore, this article aimed to systematically review the impact of hormonal changes that occur during aging on the prostate, including the role of sex hormones, insulin-like growth factor 1, thyroid hormones, and insulin. The possible explanatory mechanisms of the association between BPH-LUTS and MetS are also discussed. In particular, the presence of a male polycystic ovarian syndrome (PCOS)-equivalent may represent a possible hypothesis to support this link. Male PCOS-equivalent has been defined as an endocrine syndrome with a metabolic background, which predisposes to the development of type II diabetes mellitus, cardiovascular diseases, prostate cancer, BPH and prostatitis in old age. Its early identification would help prevent the onset of these long-term complications.

Absence of nuclear receptors LXRs impairs immune response to androgen deprivation and leads to prostate neoplasia

Chronic inflammation is now a well-known precursor for cancer development. Infectious prostatitis are the most common causes of prostate inflammation, but emerging evidence points the role of metabolic disorders as a potential source of cancer-related inflammation. Although the widely used treatment for prostate cancer based on androgen deprivation therapy (ADT) effectively decreases tumor size, it also causes profound alterations in immune tumor microenvironment within the prostate. Here, we demonstrate that prostates of a mouse model invalidated for nuclear receptors liver X receptors (LXRs), crucial lipid metabolism and inflammation integrators, respond in an unexpected way to androgen deprivation. Indeed, we observed profound alterations in immune cells composition, which was associated with chronic inflammation of the prostate. This was explained by the recruitment of phagocytosis-deficient macrophages leading to aberrant hyporesponse to castration. This phenotypic alteration was sufficient to allow prostatic neoplasia. Altogether, these data suggest that ADT and inflammation resulting from metabolic alterations interact to promote aberrant proliferation of epithelial prostate cells and development of neoplasia. This raises the question of the benefit of ADT for patients with metabolic disorders.

Mice lacking the liver X nuclear receptors (LXRs), crucial integrators of lipid metabolism, were used to study the response of the prostate to androgen deprivation. This reveals that lack of androgens leads to chronic inflammation due to impaired clearance of castration-induced apoptotic cells, allowing production of pro-inflammatory cytokines and promoting prostate neoplasia.

Current Status and Application of Metformin for Prostate Cancer: A Comprehensive Review

Metformin, an oral biguanide used for first-line treatment of type 2 diabetes mellitus, has attracted attention for its anti-proliferative and anti-cancer effects in several solid tumors, including prostate cancer (PCa). Liver kinase B1 (LKB1) and adenosine monophosphate-activated protein kinase (AMPK) activation, inhibition of the mammalian target of rapamycin (mTOR) activity and protein synthesis, induction of apoptosis and autophagy by p53 and p21, and decreased blood insulin level have been suggested as direct anti-cancer mechanisms of metformin. Research has shown that PCa development and progression are associated with metabolic syndrome and its components. Therefore, reduction in the risk of PCa and improvement in survival in metformin users may be the results of the direct anti-cancer mechanisms of the drug or the secondary effects from improvement of metabolic syndrome. In contrast, some research has suggested that there is no association between metformin use and PCa incidence or survival. In this comprehensive review, we summarize updated evidence on the relationship between metformin use and oncological effects in patients with PCa. We also highlight ongoing clinical trials evaluating metformin as an adjuvant therapy in novel drug combinations in various disease settings.

Sorting Through the Maze of Treatment Options for Metastatic Castration-Sensitive Prostate Cancer

Since 1944, when Huggins and Hodges demonstrated the effectiveness of bilateral orchiectomy for metastatic prostate cancer (PCa), androgen deprivation therapy (ADT) has been the first-line treatment for men with advanced PCa. The proportion of PCa cases that are metastatic at diagnosis ranges globally, from 5%-20% in countries with widespread screening practices to upward of 30%-60% where screening is minimal. In the United States alone, there will be an estimated 191,000 new cases of PCa diagnosed in the year 2020, of which approximately 20% will be metastatic.¹ Ongoing controversy around prostate-specific antigen (PSA) screening practices, increased access to novel imaging modalities, and a globally aging population will drive increased rates of metastatic castration-sensitive prostate cancer (mCSPC).^2,3 At the same time, advances in upfront hormonal or chemohormonal therapy have driven a dramatic shift in treatment paradigms. In this article, we review recent advances in treatment choices for men with newly diagnosed mCSPC and the impact of upfront treatment on subsequent disease biology. Options include treatment with chemohormonal therapy, androgen receptor (AR)-directed therapy in addition to ADT, or, less commonly, ADT alone. Treatment choice must include consideration of clinical and disease characteristics, as well as patient preferences and limitations of geography and financial concerns.

Lifestyle in urology: Cancer

The opportunity to prevent, to improve their prognosis, or even to cure uro-oncological diseases by modifying the lifestyle habits is a very modern topical subject and represents a great and fascinating challenge for the future. A PubMed and Web of Science databases search has been performed to review the published knowledge on most important lifestyle habits, such as smoking, physical activity, nutrition, sexual activity, and personal hygiene, highlighting modifiable factors influencing development and progression of urological cancers. Cigarette smoking has been historically established as risk factors for urothelial cancer, and an association with risk of renal cell carcinoma and worse prognosis of prostate cancer has been sufficiently demonstrated. Poor genital hygiene is a recognized risk factor for penile cancer. Furthermore, a convincing evidence has been found on the association between physical activity and both risk and prognosis of bladder and prostate cancer. Obesity is strongly associated with increased risk of developing lethal prostate cancer. An unequivocal evidence of a direct relationship between most of the other lifestyle habits and development of the uro-oncological diseases has not been found.

Diet and Lifestyle in Prostate Cancer

A variety of diet and lifestyle factors have been studied with respect to prostate cancer risk in large, prospective cohort studies. In spite of this work, and in contrast to other common cancers, few modifiable risk factors have been firmly established as playing a role in prostate cancer. There are several possible explanations for the lack of well-established risk factors. First, prostate cancer has among the highest heritability of all common cancers; second, early life exposures may play an important role in risk, rather than mid- and later-life exposures assessed in most epidemiological studies. Finally, prostate-specific antigen (PSA) screening plays a critical role in prostate cancer detection and incidence rates, which has important implications for epidemiological studies.Among modifiable risk factors, smoking and obesity are consistently associated with higher risk specifically of advanced prostate cancer. There is also considerable evidence for a positive association between dairy intake and overall prostate cancer risk, and an inverse association between cooked tomato/lycopene intake and risk of advanced disease. Several other dietary factors consistently associated with risk in observational studies, including selenium and vitamin E, have been cast into doubt by results from clinical trials. Results for other well-studied dietary factors, including fat intake, red meat, fish, vitamin D, soy and phytoestrogens are mixed.In practical terms, men concerned with prostate cancer risk should be encouraged to stop smoking, be as physically active as possible, and achieve or maintain a healthy weight. These recommendations also have the advantage of having a positive impact on risk of type 2 diabetes, cardiovascular disease, and other chronic diseases. Reducing dairy intake while increasing consumption of fish and tomato products is also reasonable advice.

Metabolic Alterations, Aggressive Hormone-Naïve Prostate Cancer and Cardiovascular Disease: A Complex Relationship

Background: Epidemiological studies suggest a possible relationship between metabolic alterations, cardiovascular disease and aggressive prostate cancer, however, no clear consensus has been reached. Objective: The aim of the study was to analyze the recent literature and summarize our experience on the association between metabolic disorders, aggressive hormone-naïve prostate cancer and cardiovascular disease. Method: We identified relevant papers by searching in electronic databases such as Scopus, Life Science Journals, and Index Medicus/Medline. Moreover, we showed our experience on the reciprocal relationship between metabolic alterations and aggressive prostate cancer, without the influence of hormone therapy, as well the role of coronary and carotid vasculopathy in advanced prostate carcinoma. Results: Prostate cancer cells have an altered metabolic homeostatic control linked to an increased aggressivity and cancer mortality. The absence of discrimination of risk factors as obesity, systemic arterial hypertension, diabetes mellitus, dyslipidemia and inaccurate selection of vascular diseases as coronary and carotid damage at initial diagnosis of prostate cancer could explain the opposite results in the literature. Systemic inflammation and oxidative stress associated with metabolic alterations and cardiovascular disease can also contribute to prostate cancer progression and increased tumor aggressivity. Conclusions: Metabolic alterations and cardiovascular disease influence aggressive and metastatic prostate cancer. Therefore, a careful evaluation of obesity, diabetes mellitus, dyslipidemia, systemic arterial hypertension, together with a careful evaluation of cardiovascular status, in particular coronary and carotid vascular disease, should be carried out after an initial diagnosis of prostatic carcinoma.

Insulin Enhances Migration and Invasion in Prostate Cancer Cells by Up-Regulation of FOXC2

Androgen deprivation therapy (ADT) is the standard treatment for advanced prostate cancer (PCa), yet many patients relapse with lethal metastatic disease. With this loss of androgens, increased cell plasticity has been observed as an adaptive response to ADT. This includes gain of invasive and migratory capabilities, which may contribute to PCa metastasis. Hyperinsulinemia, which develops as a side-effect of ADT, has been associated with increased tumor aggressiveness and faster treatment failure. We investigated the direct effects of insulin in PCa cells that may contribute to this progression. We measured cell migration and invasion induced by insulin using wound healing and transwell assays in a range of PCa cell lines of variable androgen dependency (LNCaP, 22RV1, DuCaP, and DU145 cell lines). To determine the molecular events driving insulin-induced invasion we used transcriptomics, quantitative real time-PCR, and immunoblotting in three PCa cell lines. Insulin increased invasiveness of PCa cells, upregulating Forkhead Box Protein C2 (FOXC2), and activating key PCa cell plasticity mechanisms including gene changes consistent with epithelial-to-mesenchymal transition (EMT) and a neuroendocrine phenotype. Additionally, analysis of publicly available clinical PCa tumor data showed metastatic prostate tumors demonstrate a positive correlation between insulin receptor expression and the EMT transcription factor FOXC2. The insulin receptor is not suitable to target clinically however, our data shows that actions of insulin in PCa cells may be suppressed by inhibiting downstream signaling molecules, PI3K and ERK1/2. This study identifies for the first time, a mechanism for insulin-driven cancer cell motility and supports the concept that targeting insulin signaling at the level of the PCa tumor may extend the therapeutic efficacy of ADT.

Serum glucose, triglycerides, and cholesterol in relation to prostate cancer death in the Swedish AMORIS study

PURPOSE

Lifestyle-related conditions such as obesity are associated with prostate cancer progression, but the associations with hyperglycemia and dyslipidemia are unclear. This study, therefore, aims to examine the association of glucose, triglycerides, and total cholesterol with prostate cancer death.

METHODS

From the Swedish AMORIS cohort, we selected 14,150 men diagnosed with prostate cancer between 1996 and 2011 who had prediagnostic measurements of serum glucose, triglycerides, and total cholesterol. Multivariable Cox proportional hazards regression models were used to determine the hazard ratios for death in relation to the aforementioned metabolic markers.

RESULTS

Using clinical cut-off points, a non-significant positive association was observed between glucose and prostate cancer death. When compared to those with glucose in the lowest quartile, those in the highest quartile had greater risk of prostate cancer death (HR 1.19; 95% CI 1.02-1.39). However, neither total cholesterol nor triglycerides were associated with prostate cancer death. Glucose and triglycerides were positively associated with overall, cardiovascular, and other deaths. Hypercholesterolemia was only associated with risk of CVD death.

CONCLUSION

Our results suggest that glucose levels may influence prostate cancer survival, but further studies using repeated measurements are needed to further elucidate how glucose levels may influence prostate cancer progression.

Nutrition, physical activity, and lifestyle factors in prostate cancer prevention

PURPOSE OF REVIEW

To review current evidence for prostate cancer prevention with nutrition, physical activity, and lifestyle interventions and identify future research directions.

RECENT FINDINGS

Multiple preclinical and observational studies have observed that diet, exercise, and lifestyle interventions may play a role in mitigating disease progression, mortality, and overall disease burden for high-grade and fatal prostate cancer. Increased vegetable and fruit intakes, decreased red meat and saturated fat intakes, and increased exercise are potentially associated with decreased risk of incident disease and increased progression-free, prostate cancer-specific, and overall survival. Randomized controlled trials (RCTs) have demonstrated that selenium and vitamin C supplements are ineffective in preventing incident prostate cancer and that vitamin E supplements potentially increase incident prostate cancer risk. A large RCT of a high vegetable diet intervention among prostate cancer patients on active surveillance, the Men's Eating and Living study, will soon complete analysis. An RCT for an exercise intervention among men with metastatic castrate-resistant prostate cancer is currently accruing.

SUMMARY

Although preclinical and observational studies have identified potential benefits for high vegetable, low fat, low meat diets, and increased exercise, Level I evidence is limited. To inform clinical care, future research should focus on RCTs evaluating clinical effectiveness.

Association among metabolic syndrome, inflammation, and survival in prostate cancer

BACKGROUND

Metabolic syndrome (MS) and inflammation (INF) alterations are among the factors involved in cancer progression. The study aimed to assess the relationship between MS and INF and its effect on progression-free/overall survival (PFS/OS) in metastatic castration-resistant prostate cancer (mCRPC) treaed with abiraterone or enzalutamide.

METHODS

We, retrospectively, evaluated patients with mCRPC in 7 Italian Institutes between March 2011 and October 2016. MS was defined by modified adult treatment panel-III criteria. INF was characterized by at least one of these criteria: neutrophil to lymphocyte ratio ≥ 3, elevated erythrocyte sedimentation rate or C-reactive protein.

RESULTS

Eighty-three of 551 (15.1%) patients met MS criteria at baseline and 34 (6.2%) during treatment. MS patients (MS+) presented a greater INF profile compared to MS- (P<0.0001). Median PFS was 3.7 for MS+ vs. 8.7 months for MS- (hazard ratio [HR] = 2.77; 95% CI: 2.12-3.61; P<0.0001). Median OS was 6.9 and 19 months in MS+ and MS-, respectively (HR = 3.43; 95% CI: 2.56-4.58; P<0.0001). We also demonstrated INF led to shorter PFS and OS (4.5 vs. 8.5 months, HR = 1.48, 95% CI: 1.15-1.90, P = 0.002, and 11.2 vs. 18.8 months, HR =1.66, 95% CI: 1.26-2.18, P = 0.0003, respectively). The combination of MS with INF provided the identification of high-risk prognostic group (MS+/INF+ vs. MS-/INF-) with worse PFS (3.7 vs. 9 months, HR = 2.7, 95% CI: 1.88-3.89, P<0.0001) and OS (6.3 vs. 20.4 months, HR = 4.04, 95% CI: 2.75-5.93, P<0.0001). Multivariable analysis confirmed that MS was independently associated with PFS (HR = 2.07; 95% CI: 1.03-4.18; P = 0.041) and OS (HR = 4.87; 95% CI: 2.36-10.03; P<0.0001). The absence of INF as an independent predictor of survival underlined the correlation between MS/INF.

CONCLUSIONS

Pretreatment identification of MS and INF alterations might represent an available and easy tool for better prognostication of patients with mCRPC. A prospective evaluation is warranted.

A systematic review of the literature exploring the interplay between prostate cancer and type two diabetes mellitus

Prostate cancer (PCa) and type two diabetes mellitus (T2DM) are both increasing prevalent conditions and often occur concurrently. However, the relationship between the two is more complex than just two prevalent conditions co-existing. This review systematically explores the literature around the interplay between the two conditions. It covers the impact of pre-existing T2DM on PCa incidence, grade and stage, as well as exploring the impact of T2DM on PCa outcomes and mortality and the interaction between T2DM and PCa treatments.

Drugs for metabolic conditions and prostate cancer death in men on GnRH agonists

OBJECTIVE

To evaluate whether drugs for metabolic conditions influence prostate cancer-specific mortality in men starting gonadotrophin-releasing hormone (GnRH) agonists, as it is unclear whether metabolic syndrome and its related drugs is affecting treatment response in men with prostate cancer on GnRH agonists.

PATIENTS AND METHODS

We selected all men receiving GnRH agonists as primary treatment in the Prostate Cancer data Base Sweden (PCBaSe) (n = 9267). Use of drugs for metabolic conditions (i.e. anti-diabetes, anti-dyslipidaemia, and antihypertension) in relation to all-cause, cardiovascular disease (CVD), and prostate cancer-specific death were studied using multivariate Cox proportional hazard and Fine and Gray competing regression models.

RESULTS

In all, 6322 (68%) men used at least one drug for a metabolic condition at GnRH agonist initiation: 46% on antihypertensive drugs only, 32% on drugs for dyslipidaemia and hypertension, and ~10% on drugs for more than two metabolic conditions. Cox models indicated a weak increased risk of prostate cancer death in men who were on drugs for hypertension only (hazard ratio [HR] 1.12, 95% confidence interval [CI] 1.03-1.23) or drugs for hyperglycaemia (HR 1.19, 95% CI 1.06-1.35) at GnRH agonist initiation. However, upon taking into account competing risk from CVD death, none of the drugs for metabolic conditions were associated with an increased risk of prostate cancer death.

CONCLUSION

We did not find evidence for a better or worse response to GnRH agonists in men with prostate cancer who were also on drugs for hypertension, dyslipidaemia, or hyperglycaemia.

Metformin and longevity (METAL): a window of opportunity study investigating the biological effects of metformin in localised prostate cancer

BACKGROUND

Metformin is a biguanide oral hypoglycaemic agent commonly used for the treatment of type 2 diabetes mellitus. In addition to its anti-diabetic effect, metformin has also been associated with a reduced risk of cancer incidence of a number of solid tumours, including prostate cancer (PCa). However, the underlying biological mechanisms for these observations have not been fully characterised in PCa. One hypothesis is that the indirect insulin lowering effect may have an anti-neoplastic action as elevated insulin and insulin like growth factor - 1 (IGF-1) levels play a role in PCa development and progression. In addition, metformin is a potent activator of activated protein kinase (AMPK) which in turn inhibits the mammalian target of rapamycin (mTOR) and other signal transduction mechanisms. These direct effects can lead to reduced cell proliferation. Given its wide availability and tolerable side effect profile, metformin represents an attractive potential therapeutic option for men with PCa. Hence, the need for a clinical trial investigating its biological mechanisms in PCa.

METHODS

METAL is a randomised, placebo-controlled, double-blind, window of opportunity study investigating the biological mechanism of metformin in PCa. 100 patients with newly-diagnosed, localised PCa scheduled for radical prostatectomy will be randomised 1:1 to receive metformin (1 g b.d.) or placebo for four weeks (+/- 1 week) prior to prostatectomy. Tissue will be collected from both diagnostic biopsy and prostatectomy specimens. The primary endpoint is the difference in expression levels of markers of the Fatty acid synthase (FASN)/AMPK pathway pre and post treatment between the placebo and metformin arms. Secondary endpoints include the difference in expression levels of indicators of proliferation (ki67 and TUNEL) pre and post treatment between the placebo and metformin arms. METAL is currently open to recruitment at Guy's and St Thomas' Hospital and the Royal Marsden Hospital, London.

DISCUSSION

This randomised placebo-controlled double blinded trial of metformin vs. placebo in men with localised PCa due to undergo radical prostatectomy, aims to elucidate the mechanism of action of metformin in PCa cells, which should then enable further larger stratification trials to take place.

TRIAL REGISTRATION

EudraCT number 2014-005193-11 . Registered on September 09, 2015.

Metformin and Prostate Cancer: a New Role for an Old Drug

Purpose of Review

Since epidemiological studies first demonstrated a potential positive effect of metformin in reducing cancer incidence and mortality, there has been an increased interest in not only better understanding metformin’s mechanisms of action but also in exploring its potential anti-cancer effects. In this review, we aim to summarise the current evidence exploring a role for metformin in prostate cancer therapy.

Recent Findings

Preclinical studies have demonstrated a number of antineoplastic biological effects via a range of molecular mechanisms. Data from retrospective epidemiological studies in prostate cancer has been mixed; however, there are several clinical trials currently underway evaluating metformin’s role as an anti-cancer agent. Early studies have shown benefits of metformin to inhibit cancer cell proliferation and improve metabolic syndrome in prostate cancer patients receiving androgen deprivation therapy (ADT).

Summary

While the body of evidence to support a role for metformin in prostate cancer therapy is rapidly growing, there is still insufficient data from randomised trials, which are currently still ongoing. However, evidence so far suggests metformin could be a useful adjuvant agent, particularly in patients on ADT.

Association between type 2 diabetes, curative treatment and survival in men with intermediate- and high-risk localized prostate cancer

OBJECTIVE

To investigate whether curative prostate cancer (PCa) treatment was received less often by men with both PCa and Type 2 diabetes mellitus (T2DM) as little is known about the influence of T2DM diagnosis on the receipt of such treatment in men with localized PCa.

SUBJECTS AND METHODS

The Prostate Cancer database Sweden (PCBaSe) was used to obtain data on men with T2DM and PCa (n = 2210) for comparison with data on men with PCa only (n = 23 071). All men had intermediate- (T1-2, Gleason score 7 and/or prostate-specific antigen [PSA] 10-20 ng/mL) or high-risk (T3 and/or Gleason score 8-10 and/or PSA 20-50 ng/mL) localized PCa diagnosed between 1 January 2006 and 31 December 2014. Multivariate logistic regression was used to calculate the odds ratios (ORs) for receipt of curative treatment in men with and without T2DM. Overall survival, for up to 8 years of follow-up, was calculated both for men with T2DM only and for men with T2DM and PCa.

RESULTS

Men with T2DM were less likely to receive curative treatment for PCa than men without T2DM (OR 0.78, 95% confidence interval 0.69-0.87). The 8-year overall survival rates were 79% and 33% for men with T2DM and high-risk PCa who did and did not receive curative treatment, respectively.

CONCLUSIONS

Men with T2DM were less likely to receive curative treatment for localized intermediate- and high-risk PCa. Men with T2DM and high-risk PCa who received curative treatment had substantially higher survival times than those who did not. Some of the survival differences represent a selection bias, whereby the healthiest patients received curative treatment. Clinicians should interpret this data carefully and ensure that individual patients with T2DM and PCa are not under- nor overtreated.

Exercise-induced biochemical changes and their potential influence on cancer: a scientific review

AIM

To review and discuss the available international literature regarding the indirect and direct biochemical mechanisms that occur after exercise, which could positively, or negatively, influence oncogenic pathways.

METHODS

The PubMed, MEDLINE, Embase and Cochrane libraries were searched for papers up to July 2016 addressing biochemical changes after exercise with a particular reference to cancer. The three authors independently assessed their appropriateness for inclusion in this review based on their scientific quality and relevance.

RESULTS

168 papers were selected and categorised into indirect and direct biochemical pathways. The indirect effects included changes in vitamin D, weight reduction, sunlight exposure and improved mood. The direct effects included insulin-like growth factor, epigenetic effects on gene expression and DNA repair, vasoactive intestinal peptide, oxidative stress and antioxidant pathways, heat shock proteins, testosterone, irisin, immunity, chronic inflammation and prostaglandins, energy metabolism and insulin resistance.

SUMMARY

Exercise is one of several lifestyle factors known to lower the risk of developing cancer and is associated with lower relapse rates and better survival. This review highlights the numerous biochemical processes, which explain these potential anticancer benefits.

The emerging role of obesity, diet and lipid metabolism in prostate cancer

Obesity is associated with an increased risk of a number of serious medical conditions, including cancer. As far as prostate cancer is concerned, obesity is associated with an increased risk of high-grade tumors, which is possibly related to lower androgen levels. Diet may also affect prostate cancer risk since countries with a higher dietary fat intake also present higher prostate cancer mortality rates. Interestingly, prostate cancer is associated with a number of metabolic alterations that may provide valuable diagnostic and therapeutic targets. This review explores the available clinical as well as biological evidence supporting the relationship between obesity, diet, alteration in metabolic pathways and prostate cancer.

The combination of serum insulin, osteopontin, and hepatocyte growth factor predicts time to castration-resistant progression in androgen dependent metastatic prostate cancer- an exploratory study

BACKGROUND

We hypothesized that pretreatment serum levels of insulin and other serum markers would predict Progression-free survival (PFS), defined as time to castration-resistant progression or death, in metastatic androgen-dependent prostate cancer (mADPC).

METHODS

Serum samples from treatment-naïve men participating in a randomized phase 3 trial of ADT +/- chemotherapy were retrospectively analyzed using multiplex assays for insulin and multiple other soluble factors. Cox proportional hazards regression models were used to identify associations between individual factor levels and PFS.

RESULTS

Sixty six patients were evaluable (median age = 72 years; median prostate surface antigen [PSA] = 31.5 ng/mL; Caucasian = 86 %; Gleason score ≥8 = 77 %). In the univariable analysis, higher insulin (HR = 0.81 [0.67, 0.98] p = 0.03) and C-peptide (HR = 0.62 [0.39, 1.00]; p = 0.05) levels were associated with a longer PFS, while higher Hepatocyte Growth Factor (HGF; HR = 1.63 [1.06, 2.51] p = 0.03) and Osteopontin (OPN; HR = 1.56 [1.13, 2.15]; p = 0.01) levels were associated with a shorter PFS. In multivariable analysis, insulin below 2.1 (ln scale; HR = 2.55 [1.24, 5.23]; p = 0.011) and HGF above 8.9 (ln scale; HR = 2.67 [1.08, 3.70]; p = 0.027) levels were associated with longer PFS, while adjusted by OPN, C-peptide, trial therapy and metastatic volume. Four distinct risk groups were identified by counting the number of risk factors (RF) including low insulin, high HGF, high OPN levels, and low C-peptide levels (0, 1, 2, and 3). Median PFS was 9.8, 2.0, 1.6, and 0.7 years for each, respectively (p < 0.001).

CONCLUSION

Pretreatment serum insulin, HGF, OPN, and C-peptide levels can predict PFS in men with mADPC treated with ADT. Risk groups based on these factors are superior predictors of PFS than each marker alone.

Uncontrolled diabetes predicts poor response to novel antiandrogens

Metabolic abnormalities including hyperglycemia and hyperlipidemia have been associated with worse prognosis of prostate cancer (PCa), but there are limited data regarding their impact on the prognosis of castrate-resistant prostate cancer (CRPC) and the response of novel antiandrogens, namely abiraterone acetate (AA) and enzalutamide. Retrospective analysis of 61 patients with CRPC on AA or enzalutamide, treated at the Boston Medical Center, was performed. We evaluated hemoglobin A1c (HbA1c), HDL, LDL, Triglycerides and BMI within 2months before the initiation of treatment with AA or enzalutamide and progression-free survival (PFS) under this treatment. Regression analysis and analysis of variance were used to evaluate the data. HbA1c levels were found to predict adversely the PFS on the novel agents (df (1, 37), P=0.00, R(2)=0.40, coeff=-3.28). The Kaplan-Meier analysis showed that there is significant difference in survival between the HbA1c 4.7-5.9% compared with patients with HbA1c 7.8-11.6% (6.72±1.3months, log rank test P<0.0001) LDL (P=0.07), HDL (P=0.14), and triglycerides (P=0.33) were not found to predict PFS. BMI predicted PFS positively (df (1.59), P=0.02, R(2)=0.09, coeff=0.03), but not independently of HbA1c (P=0.07). No significant implications of social and family history, previous chemotherapy regimen, and Gleason score with PFS were found. Multiple markers of patients' health state were not associated with HbA1c values. Uncontrolled diabetes can predict for poor response of CRPC patients to AA and enzalutamide determining PFS under this treatment. Elevated BMI can positively affect PFS at this stage of disease.

The impact of diabetes and other metabolic disorders on prostate cancer prognosis

AIMS

To investigate the impact of diabetes mellitus (DM) and other metabolic disorders on the survival of men with prostate cancer (PCa).

METHODS

We conducted a retrospective cohort-study based on 715 men with PCa, originally enrolled in an Italian case-control study between 1995 and 2002. Anthropometric measures, self-reported medical conditions, and Gleason score were assessed at enrollment. Adjusted hazard ratios (HRs) of death, with 95% confidence intervals (95% CIs), were estimated using Fine and Gray's regression model.

RESULTS

After a median follow-up of 11.6years, 244 (34.1%) deaths occurred, 77 (31.6%) due to PCa. Excess mortality from all causes was reported in PCa patients with DM (HR=1.56, 95% CI: 1.03-2.36), which increased to 1.76 (95% CI: 0.99-3.13) when at least two out of three metabolic disorders (i.e., waist circumference ≥102cm, drug-treated hypertension, and hypercholesterolemia) were additionally present. The impact of metabolic disorders was stronger on non-PCa-specific mortality with HRs equal to 2.21 (95% CI: 1.38-3.54) for DM, 1.45 (95% CI: 0.97-2.19) for waist circumference ≥102cm, and 1.63 (95% CI: 1.19-2.22) for drug-treated hypertension.

CONCLUSIONS

DM and other metabolic disorders unfavorably affected the survival of PCa patients, mainly impacting on the risk of death from causes other than PCa.

Risk of prostate cancer-specific death in men with baseline metabolic aberrations treated with androgen deprivation therapy for biochemical recurrence

OBJECTIVES

To investigate the associations of host metabolic factors and metabolic syndrome on prostate cancer-specific death (PCSD) and overall survival (OS) in patients treated with androgen deprivation therapy (ADT) for biochemically recurrent disease.

PATIENTS AND METHODS

The analysis included 273 patients with prostate cancer treated with ADT for rising prostate-specific antigen level after surgery or radiotherapy. Patients were assessed for the presence of diabetes, hypertension, dyslipidaemia and obesity before commencing ADT, and Adult Treatment Panel III criteria were used to assess the presence of the composite diagnosis of metabolic syndrome. A competing risks regression model was used to assess associations of time to PCSD with the metabolic conditions, while a multivariable Cox regression model was used to assess associations of OS with metabolic syndrome and metabolic conditions.

RESULTS

During a median follow-up of 11.6 years, 157 patients (58%) died, of whom 58 (21%) died from prostate cancer. At the start of ADT the median (range) patient age was 74 (46-92) years and the median PSA level was 3.0 ng/mL. Metabolic syndrome was observed in 31% of patients; hypertension (68%) and dyslipidaemia (47%) were the most common metabolic conditions. No association of PCSD and metabolic syndrome status was observed. Patients with hypertension tended to have a higher cumulative incidence of PCSD than those without hypertension (sub-distribution hazard ratio [HR] 1.59, 95% confidence interval [CI] 0.89, 2.84; P = 0.11) although the difference was not statistically significant. Patients with metabolic syndrome had an increased risk of death from all causes (HR 1.56, 95% CI 1.07, 2.29; P = 0.02) when compared with patients without metabolic syndrome, as did patients with hypertension (HR 1.72, 95% CI 1.18, 2.49; P = 0.004).

CONCLUSIONS

No association of PCSD and metabolic syndrome was observed in this cohort of men receiving ADT for biochemically recurrent prostate cancer. Metabolic syndrome was associated with an increased risk of death from all causes and a similar effect was also observed for patients with prostate cancer with hypertension alone.

Metabolic syndrome in castration-resistant prostate cancer patients treated with abiraterone

BACKGROUND

Metabolic syndrome (MS) has not yet been studied in castration-resistant prostate cancer (CRPC) men treated with novel hormonal therapies. The study aims to assess the impact of MS on outcome from time starting abiraterone.

PATIENTS AND METHODS

We retrospectively evaluated a consecutive series of metastatic CRPC patients treated with abiraterone after docetaxel failure. MS, as defined by modified Adult Treatment Panel (ATP) III criteria, was assessed at the time of initiation of abiraterone, during treatment and follow-up.

RESULTS

Sixty-seven of 178 patients evaluated (37.6%) met MS criteria at baseline, before abiraterone initiation, whereas for 11 (9.9%) without MS before treatment with abiraterone this occurred during treatment. Median PFS was equal to 4.7 months for patients with MS versus 9 months for those without MS. Patients with MS had an increased risk of 71% of progression or death for all causes than patients without MS (HR = 1.7, 95% CI [1.2-2.4], P = 0.03). Median OS was 14.7 months and 22.3 months in patients with and without MS, respectively. After adjusting for covariates, MS resulted not significantly associated to OS (HR = 1.42, 95% CI [0.91-2.22], P = 0.073).

CONCLUSIONS

The presence of MS is a significant risk factor for shorter PFS in CRPC patients treated with abiraterone, even if it does not show a significant impact on OS. A prospective evaluation is warranted.

Metabolic Syndrome Components are Associated with Increased Prostate Cancer Risk

Background

Our study investigated the associations of metabolic syndrome (MS) and metabolic indicators with prostate cancer (PCa) risk in the Chinese Han ethnic population.

Material/Methods

We studied 101 PCa patients (without/with MS) and 120 healthy controls. Clinical data, including waist circumference, BMI, TG, FINS, FBG, and PCa-related indicators, were collected. The correlations between MS and PCa were analyzed.

Results

Compared to PCa, PV and Gleason scores increased and PSA levels decreased in PCa with MS group (all P<0.001). PV was positively correlated with BMI, FINS, and HOMA-IR (r=0.459, P<0.001; r=0.421, P=0.001; r=0.490, P=0.003, respectively), and was negatively correlated with HDL-C (r=−0.378, P<0.001). PSA level in MS patients was negatively correlated with BMI (r=−0.125, P<0.001), TG (r=−0.256, P<0.001) and FBG (r=−0.183, P<0.001). Large PV, high TG, low HDL-C, high LDL-C, and high FBG were associated with an increased risk of PCa (P<0.001, OR=1.10, 95%CI: 1.009–3.304; P<0.001, OR=2.91, 95%CI: 1.612–5.241; P<0.001, OR=7.89, 95%CI: 3.908–15.947; P=0.015, OR=1.87, 95%CI: 1.131–3.077; P=0.004, OR=2.17, 95%CI: 1.280–3.686, respectively). MS-related indicators showed a positive relationship with PCa (P<0.001, OR=1.90, 95%CI: 1.107–10.629).

Conclusions

Our study shows that MS and metabolic indicators are associated with an increased risk of PCa, pointing to a novel therapeutic approach for PCa management.

Metabolic syndrome in the development and progression of prostate cancer

Prostate cancer (PCa) is the most common noncutaneous malignancy and second leading cause of cancer-specific mortality for men in the United States. There is a wide spectrum of aggressiveness ranging from biologically significant to indolent disease, which has led to an interest in the identification of risk factors for its development and progression. Emerging evidence has suggested an association between metabolic syndrome (MetS) and PCa. MetS represents a cluster of metabolic derangements that confer an increased risk of cardiovascular disease and type 2 diabetes mellitus. Its individual components include obesity, dyslipidemias, high blood pressure, and high fasting glucose levels. MetS has become pervasive and is currently associated with a high socioeconomic cost in both industrialized and developing countries throughout the world. The relationship between MetS and PCa is complex and yet to be fully defined. A better understanding of this relationship will facilitate the development of novel therapeutic targets for the prevention of PCa and improvement of outcomes among diagnosed men in the future. In this review, we evaluate the current evidence on the role of MetS in the development and progression of PCa. We also discuss the clinical implications on the management of PCa and consider the future direction of this subject.

Androgen receptor roles in insulin resistance and obesity in males: the linkage of androgen-deprivation therapy to metabolic syndrome

Prostate cancer (PCa) is one of the most frequently diagnosed malignancies in men. Androgen-deprivation therapy (ADT) is the first-line treatment and fundamental management for men with advanced PCa to suppress functions of androgen/androgen receptor (AR) signaling. ADT is effective at improving cancer symptoms and prolonging survival. However, epidemiological and clinical studies support the notion that testosterone deficiency in men leads to the development of metabolic syndrome that increases cardiovascular disease risk. The underlying mechanisms by which androgen/AR signaling regulates metabolic homeostasis in men are complex, and in this review, we discuss molecular mechanisms mediated by AR signaling that link ADT to metabolic syndrome. Results derived from various AR knockout mouse models reveal tissue-specific AR signaling that is involved in regulation of metabolism. These data suggest that steps be taken early to manage metabolic complications associated with PCa patients receiving ADT, which could be accomplished using tissue-selective modulation of AR signaling and by treatment with insulin-sensitizing agents.

Elevated insulin-like growth factor binding protein-1 (IGFBP-1) in men with metastatic prostate cancer starting androgen deprivation therapy (ADT) is associated with shorter time to castration resistance and overall survival

BACKGROUND

Insulin-like growth factor (IGF) and adipokines have been implicated in prostate cancer carcinogenesis.

METHOD

Data from 122 men with serum samples drawn within 3 months of starting ADT for metastatic prostate cancer was accessed retrospectively. IGF-1, IGF binding protein (BP)-1, leptin, and adiponectin levels were measured by multiplex electrochemiluminescence assays. A multivariable Cox model assessed the association of time to castration resistant prostate cancer (CRPC) and overall survival by the protein levels, adjusted for clinical variables, age and prostate specific antigen (PSA) levels at start of ADT, race, ECOG status, extent of metastases and were reported as hazard ratio (HR) with 95% confidence interval (CI).

RESULTS

Median follow-up and overall survival were 44 and 42.2 months, respectively. ECOG performance status (≥ 1 vs. 0) was negatively associated with overall survival [H  = 2.8 (1.1-7.0), P = 0.03], and PSA nadir <0.2 was predictive of longer time to CRPC [HR = 0.3 (0.2-0.5), P < 0.0001]. The median time to CRPC by low, middle, and top IGFBP-1 tertile distribution was 20.7, 18.1, and 12.4 months, respectively, with HR for middle versus low tertile levels 3.1 (1.7-5), P = 0.0003, and for top versus low tertile levels was 2.4 (1.3-4.2), P = 0.003. The median overall survival by low, middle and top tertile IGFBP-1 level was 48.5, 46.4, and 32.8 months, respectively, with HR for top versus low tertile 2.5 (1.2-5.1), P = 0.01. There was no association with IGF-1, adiponectin and leptin.

CONCLUSION

Elevated IGFBP-1 appears to be associated with shorter time to CRPC and lower overall survival in men with metastatic prostate cancer.

[Metabolic syndrome and prostate cancer]

The relationship between metabolic syndrome (MS) and prostate cancer (PCA) is highly complex and harbors multiple facets not least because MS is not a single entity but represents a poorly defined inhomogeneous mixture of different diseases and conditions. Although numerous studies suggest a correlation between MS or components of MS and the development of prostate cancer, current evidence cannot be considered convincing. While diabetes appears to be inversely related to PCA, increased serum levels of triglycerides, cholesterol and insulin-like growth factor 1 (IGF-1) may be predictive for high grade disease. Further studies suggested that MS and high serum insulin levels are independent predictors of an unfavorable prognosis in patients with metastatic PCA. Early detection and improved therapeutic options have dramatically prolonged the course of the disease in advanced PCA through the last decades. As a consequence, development of MS in patients undergoing hormone therapy along with the cardiovascular risks has gained increasing relevance. Based on this evolution prevention, early detection and sustainable therapy represent an important clinical challenge to modern urologists active in urooncology.

Metformin in chemotherapy-naive castration-resistant prostate cancer: a multicenter phase 2 trial (SAKK 08/09)

BACKGROUND

There is evidence linking metformin to improved prostate cancer (PCa)-related outcomes.

OBJECTIVE

To evaluate treatment with metformin in patients with castration-resistant PCa (CRPC) and the effect of the treatment on progression-free survival (PFS) and PSA doubling time (PSA DT).

DESIGN, SETTING, AND PARTICIPANTS

Forty-four men with progressive metastatic CRPC from 10 Swiss centers were included in this single-arm phase 2 trial between December 2010 and December 2011.

INTERVENTION

Patients received metformin 1000 mg twice daily until disease progression.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary end point was the absence of disease progression at 12 wk. Simon two-stage optimal design was applied. With a 5% significance level and 90% power, 44 patients were required to test PFS at 12 wk ≤ 15% (H0) compared with ≥ 35% (H1).

RESULTS AND LIMITATIONS

Thirty-six percent of patients were progression-free at 12 wk, 9.1% were progression-free at 24 wk, and in two patients a confirmed ≥ 50% prostate-specific antigen (PSA) decline was demonstrated. In 23 patients (52.3%) we observed a prolongation of PSA DT after starting metformin. The homeostatic model assessment index fell by 26% from baseline to 12 wk, indicating an improvement in insulin sensitivity. There was a significant change in insulin-like growth factor-1 and insulin-like growth factor binding protein 3 from baseline to 12 wk. Sample size and lack of a control arm are the limitations of this trial; analyses are therefore exploratory.

CONCLUSIONS

Treatment with metformin is safe in nondiabetic patients, and it yields objective PSA responses and may induce disease stabilization. The activity of metformin in PCa, along with its low cost, favorable toxicity profile, and positive effect on metabolic parameters, suggests that further investigation of metformin as therapy for patients with PCa is of interest.

PATIENT SUMMARY

In this trial we assessed the use of the diabetes mellitus drug metformin in patients with advanced prostate cancer. We found disease stabilization and prolongation of prostate-specific antigen doubling time in some patients as well as effects on metabolic parameters.

TRIAL REGISTRATION

This study is registered with ClinicalTrials.gov with the identifier NCT01243385.

PREVIOUS PRESENTATION

The study was presented at ESMO 2012 (abstract 1460).

Metabolic syndrome as a peculiar target for management of prostate cancer patients

An interesting and reciprocal association between the metabolic syndrome and prostate cancer has been identified. Metabolic alterations, such as hyperinsulinemia, increased levels of insulin growth factor-1, and insulin resistance could be on the basis of development and progression of many tumors, including prostate cancer, and changes in body composition, in turn, can represent some side effects of androgen deprivation therapy and novel drugs, such as mammalian target of rapamycin inhibitors. This review evaluates this interrelation between metabolic syndrome and prostate tumor scanning in many clinical and preclinical epidemiological studies and describes possible pathogenetic biological mechanisms. Finally, this article discusses feasible clinical implications for the management, prevention, diagnosis, prognosis, and treatment of patients affected by metabolic syndrome and prostate cancer, with particular attention to the metformin action.

Efficacy versus effectiveness study design within the European screening trial for prostate cancer: consequences for cancer incidence, overall mortality and cancer-specific mortality

OBJECTIVE

To assess the impact of different study designs on outcome data within the European Randomized Study of Screening for Prostate Cancer (ERSPC).

METHODS

Observed data from the Gothenburg centre (effectiveness trial with upfront randomization before informed consent) and the Rotterdam centre (efficacy trial with randomization after informed consent) were compared with expected data, which were retrieved from national cancer registries and life tables. Endpoints were 11-year cumulative prostate cancer (PC) incidence, overall mortality and PC-specific mortality.

RESULTS

In Gothenburg, the 11-year PC incidence was higher than predicted (5.8%) in both the intervention (12.4%) and control arms (7.3%). The observed overall mortality was higher than predicted (15.9%) in both the intervention (17.8%) and control arms (18.5%). The observed PC-specific mortality in the intervention arm was 0.56% versus 0.83% in the control arm, while the expected mortality was 0.83%. In Rotterdam, the observed PC incidence in the intervention arm (10.4%) was higher than expected (4.4%). The incidence in the control arm was 4.6%. The observed overall mortality was lower than expected: 13.6% in the intervention arm and 14.0% in the control arm versus an expected mortality of 16.1%. The observed PC-specific mortality was lower than expected (0.65%) in both the intervention (0.27%) and control arms (0.41%).

CONCLUSIONS

Our results suggest that an efficacy trial with informed consent prior to randomization may have introduced a 'healthy screenee bias'. Therefore, an effectiveness trial with consent after randomization may more accurately estimate the PC-specific mortality reduction if population-based screening is introduced.

New players for advanced prostate cancer and the rationalisation of insulin-sensitising medication

Obesity and type 2 diabetes are recognised risk factors for the development of some cancers and, increasingly, predict more aggressive disease, treatment failure, and cancer-specific mortality. Many factors may contribute to this clinical observation. Hyperinsulinaemia, dyslipidaemia, hypoxia, ER stress, and inflammation associated with expanded adipose tissue are thought to be among the main culprits driving malignant growth and cancer advancement. This observation has led to the proposal of the potential utility of "old players" for the treatment of type 2 diabetes and metabolic syndrome as new cancer adjuvant therapeutics. Androgen-regulated pathways drive proliferation, differentiation, and survival of benign and malignant prostate tissue. Androgen deprivation therapy (ADT) exploits this dependence to systemically treat advanced prostate cancer resulting in anticancer response and improvement of cancer symptoms. However, the initial therapeutic response from ADT eventually progresses to castrate resistant prostate cancer (CRPC) which is currently incurable. ADT rapidly induces hyperinsulinaemia which is associated with more rapid treatment failure. We discuss current observations of cancer in the context of obesity, diabetes, and insulin-lowering medication. We provide an update on current treatments for advanced prostate cancer and discuss whether metabolic dysfunction, developed during ADT, provides a unique therapeutic window for rapid translation of insulin-sensitising medication as combination therapy with antiandrogen targeting agents for the management of advanced prostate cancer.

Metformin: multi-faceted protection against cancer

The biguanide metformin, a widely used drug for the treatment of type 2 diabetes, may exert cancer chemopreventive effects by suppressing the transformative and hyperproliferative processes that initiate carcinogenesis. Metformin's molecular targets in cancer cells (e.g., mTOR, HER2) are similar to those currently being used for directed cancer therapy. However, metformin is nontoxic and might be extremely useful for enhancing treatment efficacy of mechanism-based and biologically targeted drugs. Here, we first revisit the epidemiological, preclinical, and clinical evidence from the last 5 years showing that metformin is a promising candidate for oncology therapeutics. Second, the anticancer effects of metformin by both direct (insulin-independent) and indirect (insulin-dependent) mechanisms are discussed in terms of metformin-targeted processes and the ontogenesis of cancer stem cells (CSC), including Epithelial-to-Mesenchymal Transition (EMT) and microRNAs-regulated dedifferentiation of CSCs. Finally, we present preliminary evidence that metformin may regulate cellular senescence, an innate safeguard against cellular immortalization. There are two main lines of evidence that suggest that metformin's primary target is the immortalizing step during tumorigenesis. First, metformin activates intracellular DNA damage response checkpoints. Second, metformin attenuates the anti-senescence effects of the ATP-generating glycolytic metabotype-the Warburg effect-, which is required for self-renewal and proliferation of CSCs. If metformin therapy presents an intrinsic barrier against tumorigenesis by lowering the threshold for stress-induced senescence, metformin therapeutic strategies may be pivotal for therapeutic intervention for cancer. Current and future clinical trials will elucidate whether metformin has the potential to be used in preventive and treatment settings as an adjuvant to current cancer therapeutics.

The Interactions between Insulin and Androgens in Progression to Castrate-Resistant Prostate Cancer

An association between the metabolic syndrome and reduced testosterone levels has been identified, and a specific inverse relationship between insulin and testosterone levels suggests that an important metabolic crosstalk exists between these two hormonal axes; however, the mechanisms by which insulin and androgens may be reciprocally regulated are not well described. Androgen-dependant gene pathways regulate the growth and maintenance of both normal and malignant prostate tissue, and androgen-deprivation therapy (ADT) in patients exploits this dependence when used to treat recurrent and metastatic prostate cancer resulting in tumour regression. A major systemic side effect of ADT includes induction of key features of the metabolic syndrome and the consistent feature of hyperinsulinaemia. Recent studies have specifically identified a correlation between elevated insulin and high-grade PCa and more rapid progression to castrate resistant disease. This paper examines the relationship between insulin and androgens in the context of prostate cancer progression. Prostate cancer patients present a promising cohort for the exploration of insulin stabilising agents as adjunct treatments for hormone deprivation or enhancers of chemosensitivity for treatment of advanced prostate cancer.

A metabolic phenotyping approach to understanding relationships between metabolic syndrome and breast tumour responses to chemotherapy

PURPOSE

Breast cancer is associated with adverse outcomes in patients with the metabolic syndrome phenotype. To study this further, we examined the relationship between serum metabolite levels and the components of metabolic syndrome with treatment outcomes in breast cancer.

METHODS

A total of 88 women with measurable breast cancer were studied; their serum metabolites as assessed by (1)H nuclear magnetic resonance spectroscopy, blood pressure, lipids, glucose, body mass index and waist circumference were recorded and correlated with treatment response.

RESULTS

We identified metabolic syndrome in approximately half of our cohort (42 patients) and observed a significant trend (P = 0.03) of increased incidence of metabolic syndrome in partial response (33.3%), stable disease (42.9%) and progressive disease groups (66.1%). High blood sugar predicted a poor response (P < 0.001). Logistic regression of metabonomic data demonstrated that high lactate (P = 0.03) and low alanine (P = 0.01) combined with high glucose (P = 0.01) were associated with disease progression.

CONCLUSIONS

Metabolic syndrome is commonly observed in metastatic breast cancer and these patients have poorer outcomes. These data, which support our previous findings, suggest that high blood glucose as part of metabolic syndrome is associated with a poor response in breast cancer. They also validate new therapeutic approaches that focus on metabolism.