Prostate cancer: another aspect of the insulin-resistance syndrome?

Decoding the Influence of Obesity on Prostate Cancer and Its Transgenerational Impact

In recent decades, the escalating prevalence of metabolic disorders, notably obesity and being overweight, has emerged as a pressing concern in public health. Projections for the future indicate a continual upward trajectory in obesity rates, primarily attributable to unhealthy dietary patterns and sedentary lifestyles. The ramifications of obesity extend beyond its visible manifestations, intricately weaving a web of hormonal dysregulation, chronic inflammation, and oxidative stress. This nexus of factors holds particular significance in the context of carcinogenesis, notably in the case of prostate cancer (PCa), which is a pervasive malignancy and a leading cause of mortality among men. A compelling hypothesis arises from the perspective of transgenerational inheritance, wherein genetic and epigenetic imprints associated with obesity may wield influence over the development of PCa. This review proposes a comprehensive exploration of the nuanced mechanisms through which obesity disrupts prostate homeostasis and serves as a catalyst for PCa initiation. Additionally, it delves into the intriguing interplay between the transgenerational transmission of both obesity-related traits and the predisposition to PCa. Drawing insights from a spectrum of sources, ranging from in vitro and animal model research to human studies, this review endeavors to discuss the intricate connections between obesity and PCa. However, the landscape remains partially obscured as the current state of knowledge unveils only fragments of the complex mechanisms linking these phenomena. As research advances, unraveling the associated factors and underlying mechanisms promises to unveil novel avenues for understanding and potentially mitigating the nexus between obesity and the development of PCa.

Poorly Controlled Diabetes Mellitus Increases the Risk of Deaths and Castration-Resistance in Locally Advanced Prostate Cancer Patients

The association between DM and prostate cancer progression remains controversial. Previous studies mainly focused on early stage prostate cancer patients. We aimed to study the association between DM and prostate cancer progression in locally advanced prostate cancer patients. 598 locally advanced prostate cancer patients in a top tertiary hospital in China between 2012 and 2021 were divided into three groups based on the postoperative average HbA1c level. The follow-up time is 46.96 ± 27.07 months. Three hundred and forty-eight (58.2%) were normal glucose, 175 (29.3%) were moderate glucose, and 75 (12.5%) were high glucose. Higher postoperative-average HbA1c was associated with poorer OS, PCSM, and PSA-RFS. We concluded that poorly controlled DM was correlated with poorer OS, PCSM, and PSA-RFS in locally advanced prostate cancer patients.

Nutritional and surgical aspects in prostate disorders

Prostate disorders are commonplace in medicine, especially in older men, with prostatitis, benign prostatic hyperplasia, and prostate cancer being the most abundant pathologies. The complexity of this organ, however, turns treatment into a challenge. In this review, we aim to provide insight into the efficacy of alternative treatments, which are not normally used in conventional medicine, with a particular focus on nutrients. In order to understand why and how nutrition can be beneficial in diseases of the prostate, we give an overview of the known characteristics and features of this organ. Then, we provide a summary of the most prevalent prostate illnesses. Finally, we propose nutrition-based treatment in each of these prostate problems, based on in-depth research concerning its effects in this context, with an emphasis on surgery. Overall, we plead for an upgrade of this form of alternative treatment to a fully recognized mode of therapy for the prostate.

Insulin signaling, androgen receptor and PSMA immunohistochemical analysis by semi-automated tissue microarray in prostate cancer with diabetes (DIAMOND study)

In the last years, many studies have highlighted the hypothesis that diabetes and hyperglycemia could be relevant for prostate cancer (PC) development and progression. We aimed to identify the prognostic value of tissue expression of androgen receptor (AR), Prostate-Specific Membrane Antigen (PSMA), Ki-67, insulin receptors (IR)  α and β, insulin growth factor-1 (IGF-1) receptor, in patients with PC and to evaluate their association with diabetes. We retrospectively collected data from 360 patients who underwent radical prostatectomy for PC or surgery for benign prostatic hyperplasia (BPH), between 2010 and 2020. We constructed tissue microarray for immunohistochemistry (IHC) analysis. In the final cohort (76 BPH and 284 PC), 57 (15.8%) patients had diabetes, 17 (22.37%) in BPH and 40 (14.08%) in PC (P = 0.08). IR-α was more expressed in patients with PC compared to the BPH Group (95.96% vs 4.04%; P <0.01). We found that AR was associated with increased risk of International Society of Urological Pathology (ISUP) score ≥4 (OR: 2.2; P <0.05), higher association with Ki-67 (OR: 2.2; P <0.05) and IR-α (OR: 5.7; P <0.05); IGF-1 receptor was associated with PSMA (OR: 2.8; P <0.05), Ki-67 (OR: 3.5; P <0.05) and IR-β (OR: 5.1; P <0.05). Finally, IGF-1 receptor was predictive of ISUP ≥ 4 (OR: 16.5; P =0.017) in patients with PC and diabetes. In the present study we highlighted how prostate cancer patients have a different protein expression in the tissue. This expression, and in particular that relating to IGF-1R, is associated with greater tumor aggressiveness in those patients with diabetes. We suppose that these results are attributable to an alteration of the insulin signal which therefore determines a greater mitogenic activity that can influence tumor progression.

SRSF-1 and microvessel density immunohistochemical analysis by semi-automated tissue microarray in prostate cancer patients with diabetes (DIAMOND study)

OBJECTIVE

To study the association between insulin receptors (isoforms α and β), insulin growth factor-1 (IGF1) and serine/arginine splicing factor 1 (SRSF-1) in patients with prostate cancer (PC) and diabetes.

MATERIALS AND METHODS

We retrospectively analyzed data from 368 patients who underwent surgery for PC or benign prostatic hyperplasia (BPH) between 2010 and 2020 at the Department of Urology, University of Catania. Tissue microarray slides were constructed and they were stained for androgen receptor (AR), insulin receptor-α and -β, IGF1 (IGF1-R), Ki-67, and prostate specific membrane antigen (PSMA) expression using validated score.

RESULTS

The final cohort was represented by 100 patients with BPH and 268 with PC, with a median age of 68 years. We found that SRSF-1 expression was associated with AR (odds ratio [OR]: 1.66), PSMA (OR: 2.13), Ki-67 (OR: 5.99), insulin receptor (IR)-α (OR: 2.38), IR-β (OR: 3.48), IGF1-R (OR: 1.53), and microvascular density (MVD) was associated with PSMA (OR: 3.44), Ki-67 (OR: 2.23), IR-α (OR: 2.91), IR-β (OR: 3.02), IGF1-R (OR: 2.95), and SRSF-1 (OR: 2.21). In the sub cohort of PC patients, we found that SRSF-1 expression was associated with AR (OR: 2.34), Ki-67 (OR: 6.77), IR-α (OR: 2.7), and MVD (OR: 1.98). At the Kaplan-Meier analysis, SRSF-1⁺ patients had worse 5- and 9-year biochemical recurrence (36% and 6%) respect to SRSF-1^- (67% and 7%; p < .01) and similarly MVD⁺ patients (44% and 7%) respect to MVD^- (64% and 8%; p < .01). Restricting the analysis only in patients with PC and diabetes, we found that SRSF-1⁺ was associated with Ki-67⁺ (OR: 8.75; p < .05) and MVD⁺ (OR: 7.5; p < .05).

CONCLUSIONS

PC exhibits widespread heterogeneity in protein expression. In particular, the expressions of the SRSF-1 protein and of the MVD are associated with a worse prognosis and in particular with a greater cell proliferation. These results, although preliminary, may offer new future scientific insights with the aim of highlighting possible genetic alterations linked to a greater expression of SRSF-1 and associated with a worse prognosis.

Nonalcoholic fatty liver disease and risk of prostatic diseases: Roles of insulin resistance

Nonalcoholic fatty liver disease (NAFLD), the liver component of metabolic syndrome, is considered to be associated with high risk of prostatic diseases but a systematic review has not been conducted. Under a comprehensive review of the eligible clinical studies, a potential positive association between NAFLD and benign prostatic hyperplasia/prostate cancer (BPH/PCa) has been postulated. Insulin resistance and metabolic aberrations are considered to be the potential mechanism for such association. However, the relationship between NAFLD and other prostatic diseases, that is, prostatic inflammation and lower urinary tract symptoms, seems vague due to limited relevant studies in the literatures. The present review highlights that clinicians should be conscious of the detrimental effect of NAFLD on the development of BPH and PCa.

Nonalcoholic Fatty Liver Disease Is Associated with Benign Prostate Hyperplasia

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is associated with a wide spectrum of metabolic abnormalities. This study aimed to evaluate whether NAFLD is associated with benign prostatic hyperplasia (BPH) independent of other risk factors.

METHODS

A total of 3,508 subjects who underwent prostate and hepatic ultrasonography were enrolled. NAFLD was diagnosed and graded by ultrasonographic findings. BPH was defined by total prostate volume.

RESULTS

The prevalence of BPH was significantly increased according to NAFLD severity (P < 0.001). The multivariate analysis showed that NAFLD was associated with a 22% increase in the risk of BPH (odds ratio [OR], 1.22; 95% confidence interval [CI], 1.02-1.45). In non-obese subjects, NAFLD was associated with a 41% increase in the risk of BPH (OR, 1.41; 95% CI, 1.14-1.73), and an incremental increase in the risk of BPH according to NAFLD severity was pronounced (adjusted OR [95% CI], 1.32 [1.05-1.68] for mild NAFLD, 1.55 [1.15-2.10] for moderate to severe NAFLD vs. no NAFLD, P for trend = 0.004). However, in the obese population, the association of NAFLD in the risk of BPH was insignificant (P = 0.208).

CONCLUSION

NAFLD is associated with an increased risk of BPH regardless of metabolic syndrome, especially in non-obese subjects. An incrementally increased risk of BPH according to NAFLD severity is prominent in non-obese subjects with NAFLD. Thus, physicians caring for non-obese patients with NAFLD may consider assessing the risk of BPH and associated urologic conditions.

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.

Dietary Nutrient Patterns and Prostate Cancer Risk: A Case-Control Study from Iran

Background:

Prostate cancer is the second common cancer in the world. Although some associations between dietary intakes and prostate cancer have been found, the effects of dietary nutrients interactions have not yet evaluated. The aim of this study is to assess the association between nutrient patterns and risk of prostate cancer.

Methods and Materials:

Ninety-seven patients with prostate cancer and 205 controls were asked about their demographic and dietary intakes using validated questionnaires. To extract nutrient patterns, Principal Component Analysis (PCA) based on the 35 nutrient items were applied. Varimax rotation was used for improving interpretation and minimizing correlation between the factors. Logistic regression was used to determine the odds ratio (OR) with 95% confidence interval (CI) of prostate cancer by higher scores on the nutrient patterns.

Results:

High adherence to the “plant source” pattern was negatively associated with prostate cancer risk (OR 0.29 for the highest vs. the lowest score tertile; 95% CI= 0.13 – 0.65; P value for trend: <0.003). Similarly, the “antioxidant and fiber” pattern was associated with decreasing risk of prostate cancer (OR 0.06 for the highest vs. the lowest score tertile;95% CI=0.02 – 0.19; P value for trend: <0.001). There was no significant association for the “mixed” and “vitamin and minerals” pattern with risk of prostate cancer.

Conclusion:

This study confirms the potential and important role of nutrients on prostate cancer risk. Our finding revealed that “antioxidant and fiber” and “plant source” pattern is inversely associated with prostate cancer risk; however, further longitudinal and trial studies are needed to make a firm conclusion.

Systems Oncology: Bridging Pancreatic and Castrate Resistant Prostate Cancer

Large investments by pharmaceutical companies in the development of new antineoplastic drugs have not been resulting in adequate advances of new therapies. Despite the introduction of new methods, technologies, translational medicine and bioinformatics, the usage of collected knowledge is unsatisfactory. In this paper, using examples of pancreatic ductal adenocarcinoma (PaC) and castrate-resistant prostate cancer (CRPC), we proposed a concept showing that, in order to improve applicability of current knowledge in oncology, the re-clustering of clinical and scientific data is crucial. Such an approach, based on systems oncology, would include bridging of data on biomarkers and pathways between different cancer types. Proposed concept would introduce a new matrix, which enables combining of already approved therapies between cancer types. Paper provides a (a) detailed analysis of similarities in mechanisms of etiology and progression between PaC and CRPC, (b) diabetes as common hallmark of both cancer types and (c) knowledge gaps and directions of future investigations. Proposed horizontal and vertical matrix in cancer profiling has potency to improve current antineoplastic therapy efficacy. Systems biology map using Systems Biology Graphical Notation Language is used for summarizing complex interactions and similarities of mechanisms in biology of PaC and CRPC.

Serum C-peptide concentration and prostate cancer: A meta-analysis of observational studies

BACKGROUND

The association between serum C-peptide concentration and prostate cancer remains unexplored. Therefore, we conducted a meta-analysis to assess whether C-peptide serum concentrations are associated with increased prostate cancer risk.

METHODS

Several databases were searched to identify relevant original research articles published before November 2017. Random-effects models were used to summarize the overall estimate of the multivariable-adjusted odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Nine observational studies involving 11,796 participants were identified. The findings of the meta-analysis indicated that the association between serum C-peptide concentration and prostate cancer was not significant (OR: 1.15, 95% CI: 0.85-1.54; for highest versus lowest category C-peptide concentrations, P = .376). The associations were inconsistent, as indicated by subgroup analyses.

CONCLUSION

Although our findings provided no support for the hypothesis that serum C-peptide concentration is associated with excess risk of prostate cancer, people must pay attention to this aspect and increase physical activity or modify dietary habits to constrain insulin secretion, which possibly lead to decreased incidence of prostate cancer. Hence, well-designed observational studies involving different ethnic populations are still needed.

Metabesity and urological cancers

Metabolic syndrome is one of today's most important health problems. Due to increased prevalence of metabolic syndrome in society, studies done on this topic have increased in number. Although metabolic syndrome was previously considered to be important only for cardiovascular health, it has been learned that with new data, human health is compromised more thoroughly by metabolic syndrome and is also a danger to malignancy. As a result, a new definition in the form of metabesity has been introduced. In this review, available information on metabesity and urological cancers is presented.

An update of research evidence on nutrition and prostate cancer

BACKGROUND

Prostate cancer (PCa) remains a leading cause of mortality in US and other countries. Preclinical and clinical studies have examined the role of nutrition and dietary intake on the incidence and progression of PCa with mixed results.

OBJECTIVE

The objective of this chapter is to provide an update of recent published literature and highlight progress in the field.

MAIN FINDINGS

Low carbohydrate intake, soy protein, ω3 fat, green teas, tomatoes and tomato products and the herbal mixture-zyflamend showed promise in reducing PCa risk or progression. On the contrary, a higher animal fat intake and a higher β-carotene status may increase risk. A "U" shape relationship may exist between folate, vitamin C, vitamin D and calcium with PCa risk. Conclusion Despite the inconclusive findings, the potential for a role of dietary intake for the prevention and treatment of PCa remains promising. Maintaining a healthy body weight and following a healthy dietary pattern including antioxidant rich fruits and vegetables, reduced animal fat and refined carbohydrates, should be encouraged.

CONCLUSION

Despite the inconclusive findings, the potential for a role of dietary intake for the prevention and treatment of PCa remains promising. Maintaining a healthy body weight and following a healthy dietary pattern including antioxidant rich fruits and vegetables, reduced animal fat and refined carbohydrates, should be encouraged.

Metabolic syndrome and benign prostatic hyperplasia: An update

Metabolic syndrome (MetS) is a cluster of metabolic abnormalities related to central adiposity and insulin resistance. Its importance is increasingly recognized as it associates with increased risks of metabolic and cardiovascular diseases. These metabolic aberrations of MetS may lead to development of benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS) in men. A 26.5%-55.6% prevalence of MetS in men with LUTS was reported in worldwide studies. Although the exact biological pathway is not clear yet, insulin resistance, increased visceral adiposity, sex hormone alterations and cellular inflammatory reactions played significant roles in the related pathophysiological processes. Clinician should recognize the cardiovascular and metabolic impacts of MetS in men with LUTS, early risk factors optimization and use of appropriate medical therapy may possibly alter or slower the progression of LUTS/BPH, and potentially avoid unnecessary morbidities and mortalities from cardiovascular and metabolic diseases for those men.

Relationship Between Aerobic Fitness, the Serum IGF-1 Profiles of Healthy Young Adult African American Males, and Growth of Prostate Cancer Cells

The growth of prostate tumors is mediated by the bioavailability of androgens and insulin-like growth factors. This study tested the hypothesis that healthy young adult African American men exhibiting low aerobic capacity (fitness) have serum insulin-like growth Factor-1 (IGF-1) and testosterone levels that promote growth of prostate cancer cells. A cross-sectional data research design was used to study groups of 18- to 26-year-old healthy men exhibiting low and moderate aerobic fitness, based on their peak oxygen consumption (VO_2peak). The individual serum levels of IGF-1, IGF-1 binding protein-3 (IGFBP-3), and testosterone were measured. In vitro growth of androgen-dependent LNCaP prostate tumor cells was measured after incubation in culture medium fortified with each subject's serum. Aerobic capacity was significantly greater in the moderate-fitness group than in the low-fitness group without an intergroup difference in body mass index. The serum IGF-1 concentration was significantly higher in the low-fitness group in the absence of an intergroup difference in serum testosterone. The serum IGFBP-3 concentration was significantly lower in the low-fitness group. Prostate tumor cell growth was significantly greater in the cultures incubated in media containing the sera of the low-fitness group than in the sera of the moderate-fitness group. These findings suggest that moderate aerobic fitness in young adults may decrease the circulating levels of free IGF-1 and lower the potential to support growth of prostate cancer cells.

Associations between fruit, vegetable and legume intakes and prostate cancer risk: results from the prospective Supplémentation en Vitamines et Minéraux Antioxydants (SU.VI.MAX) cohort

Although experimental studies suggest that fruits, vegetables and legumes may exert protective effects against prostate carcinogenesis through various bioactive compounds such as dietary fibre and antioxidants, epidemiological evidence is lacking. Notably, very few prospective studies have investigated the relationship between legume intake and prostate cancer risk. Our objective was to prospectively investigate the association between fruit, vegetable, tomato products, potatoes and legume intakes and prostate cancer risk. This study included 3313 male participants to the SUpplémentation en VItamines et Minéraux AntioXydants cohort (follow-up: 1994-2007) who completed at least three 24-h dietary records during the first 2 years of follow-up. Associations between tertiles of intake and prostate cancer risk were assessed by multivariate Cox proportional hazards models. After a median follow-up of 12·6 years, 139 incident prostate cancers were diagnosed. An inverse association was observed between prostate cancer risk and tertiles of legume intake (hazard ratio (HR)T3v.T1=0·53; 95 % CI 0·34, 0·85; P trend=0·009). This association was maintained after excluding soya and soya products from the legume group (HRT3 v.T1=0·56; 95 % CI 0·35, 0·89; P trend=0·02). No association was observed between prostate cancer risk and tertiles of intakes of fruits (P trend=0·25), vegetables (P trend=0·91), potatoes (P trend=0·77) and tomato products (P trend=0·09). This prospective study confirms the null association between fruit and non-starchy vegetable intakes and prostate cancer risk observed in most previous cohorts. In contrast, although very few prospective studies have been published on the topic, our results suggest an inverse association between legume intake and prostate cancer risk, supported by mechanistic plausibility. These results should be confirmed by large-scale observational and intervention studies.

Can metabolic disorders in aging men contribute to prostatic hyperplasia eligible for transurethral resection of the prostate (TURP)?

PURPOSE

The aim of this study was to evaluate the incidence and severity of metabolic disorders occurring in the metabolic syndrome in patients with benign prostatic hyperplasia eligible for surgical treatment.

METHODS

The study group consisted men with diagnosed benign prostatic hyperplasia. The control group consisted patients recruited from basic health care units. Abdominal circumference, body weight and blood serum metabolic parameters were determined in the experimental and control groups. The concentrations of glucose were determined, as well as total cholesterol (ChT), low-density lipoprotein (LDL), high density lipoprotein (HDL) and triglycerides (TAG), by spectrophotometric method using reagent kits.

RESULTS

In the study group 91 (60.3%) cases of metabolic syndrome (MetS) were diagnosed, while in the control group 71 (46.1%) men met the diagnostic criteria for this syndrome (p=0.018). The analysis shows a relationship between MetS in patients with BPH and concentration glucose, ChT, LDL, HDL, systolic blood pressure and diastolic blood pressure. We found no significant statistical relationship between body weight, abdominal circumference and concentration TAG, hypertension in patients and controls.

CONCLUSIONS

in the study presented in this article, statistically significant relationships between BPH and the diagnostic parameters of the metabolic syndrome were demonstrated. These results indicate to the necessity of the modification of the lifestyle, taking preventive measures in diabetes, and evaluation of lipid metabolism disorders. It is recommended to assess symptoms that may suggest BPH (as a manifestation of LUTS) in men over 50 years of age with diagnoses of metabolic disorders (including MetS), and provide them with specialist urological care in order to prevent surgical treatment of the prostate.

Diabetes mellitus and the risk of prostate cancer: an update and cumulative meta-analysis

INTRODUCTION

To provide further insight into the association between type 2 diabetes mellitus (T2DM) and the pathophysiology of prostate cancer, we conducted an updated, detailed meta-analysis of 56 published case-control and cohort studies.

METHODS

MEDLINE and EMBASE were used to identify the literature published in April 2012 related to both diabetes mellitus and prostate cancer. A sensitivity analysis was performed, and potential confounding effects were investigated using a stratified meta-analysis. A cumulative meta-analysis was also carried out to evaluate the cumulative effect estimate over time.

RESULTS

A total of 24 case-control and 32 cohort studies with information on a total of ~8,000,000 subjects and ~140,000 individuals with prostatic cancer showed published estimates of the association between diabetes and prostate cancer malignancy. The pooled effect estimate revealed a relative risk (RR) of 0.88 (95% CI, 0.82-0.93). Interestingly, there was an increased trend for Asians (RR = 1.72, n = 7) but not Americans (RR = 0.82, n = 28) and Europeans (RR = 0.86, n = 21) regarding the association between diabetes mellitus and prostate cancer. The sensitivity analysis, excluding any one study, did not significantly change the pooled RR. The range for the pooled RR when one study was omitted was 0.84-0.89.

DISCUSSION

The findings of our meta-analysis provide strong evidence of an inverse association between diabetes and prostate cancer.

CONCLUSIONS

Further research should focus on limitations in the current literature and re-assess the relationship between diabetes and prostate cancer by analyzing the two different diabetes mellitus types separately.

Dietary total and insoluble fiber intakes are inversely associated with prostate cancer risk

Although experimental data suggest a potentially protective involvement of dietary fiber in prostate carcinogenesis, very few prospective studies have investigated the relation between dietary fiber intake and prostate cancer risk, and those have had inconsistent results. Our objective was to study the association between dietary fiber intake (overall, insoluble, soluble, and from different sources, such as cereals, vegetables, fruits, and legumes) and prostate cancer risk. Stratifications by excess weight status, insulin-like growth factors, and amount of alcohol intake were also considered. This prospective analysis included 3313 men from the Supplémentation en Vitamines et Minéraux Antioxydants (SU.VI.MAX) cohort who completed at least 3 24-h dietary records. One hundred thirty-nine incident prostate cancers were diagnosed between 1994 and 2007 (median follow-up of 12.6 y). Associations between quartiles of energy-adjusted dietary fiber intake and prostate cancer risk were characterized by multivariate Cox proportional hazards models. Prostate cancer risk was inversely associated with total dietary fiber intake (HR of quartile 4 vs. quartile 1 = 0.47; 95% CI: 0.27, 0.81; P = 0.001), insoluble (HR = 0.46; 95% CI: 0.27, 0.78; P = 0.001), and legume (HR = 0.55; 95% CI: 0.32, 0.95; P = 0.04) fiber intakes. In contrast, we found no association between prostate cancer risk and soluble (P = 0.1), cereal (P = 0.7), vegetable (P = 0.9), and fruit (P = 0.4) fiber intakes. In conclusion, dietary fiber intake (total, insoluble, and from legumes but not soluble or from cereals, vegetables, and fruits) was inversely associated with prostate cancer risk, consistent with mechanistic data.

Alcohol intake increases high-grade prostate cancer risk among men taking dutasteride in the REDUCE trial

BACKGROUND

Although most studies found no association between alcohol intake and prostate cancer (PCa) risk, an analysis of the Prostate Cancer Prevention Trial found that high alcohol intake significantly increased PCa risk among men randomized to the 5α-reductase inhibitor (5-ARI) finasteride.

OBJECTIVE

Determine whether alcohol affects PCa risk among men taking the 5-ARI dutasteride.

DESIGN, SETTINGS, AND PARTICIPANTS

Reduction by Dutasteride of Prostate Cancer Events was a 4-yr, multicenter, randomized, double-blind, placebo-controlled trial to compare PCa after dutasteride administration (0.5mg/d) with placebo. Participants had a baseline prostate-specific antigen between 2.5 and 10.0 ng/ml and a recent negative prostate biopsy. Alcohol intake was determined by baseline questionnaire, and participants underwent a prostate biopsy to determine PCa status at 2 yr and 4 yr of follow-up.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Multivariable logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for the associations between alcohol intake and low-grade (Gleason <7) and high-grade (Gleason >7) PCa.

RESULTS AND LIMITATIONS

Of 6374 participants in our analysis, approximately 25% reported no alcohol consumption, 49% were moderate drinkers (one to seven drinks per week), and 26% were heavy drinkers (more than seven drinks per week). Alcohol intake was not associated with low- or high-grade PCa in the placebo arm and was not associated with low-grade PCa among men taking dutasteride. In contrast, men randomized to dutasteride and reporting more than seven drinks per week were 86% more likely to be diagnosed with high-grade PCa (p=0.01). Among alcohol abstainers, dutasteride was associated with significantly reduced risk of high-grade PCa (OR: 0.59; 95% CI, 0.38-0.90), but dutasteride was no longer associated with reduced high-grade PCa among men reporting high alcohol intake (OR: 0.99; 95% CI, 0.67-1.45).

CONCLUSIONS

Alcohol consumption negated a protective association between dutasteride and high-grade PCa.

PATIENT SUMMARY

We confirmed a prior study that alcohol affects PCa prevention in patients taking 5-ARIs. Patients taking 5-ARIs may wish to eliminate alcohol intake if they are concerned about PCa.

Diabetes mellitus and prostate cancer risk; a nationwide case-control study within PCBaSe Sweden

BACKGROUND

Diabetes mellitus (DM) increases the risk for cancer at almost all sites, but data on the association with prostate cancer are inconsistent.

METHODS

We assessed the risk of a prostate cancer diagnosis among men with type 2 (T2)DM in a nationwide population-based case-control study including 44,352 men with prostate cancer identified through the Prostate Cancer data Base Sweden (PCBaSe) between 2002 and 2006 and 221,495 age-matched men from the general population.

RESULTS

Overall, the risk of prostate cancer among men with T2DM was lower than among men without T2DM [OR, 0.80; 95% confidence interval (CI), 0.76-0.85]. The risk decreased with longer disease duration and was observed across all tumor risk categories, although most clearly among men with low risk tumors (OR, 0.71; 95% CI, 0.64-0.80). The risk for prostate cancer was reduced among diabetic men on dietary treatment only (OR, 0.89; 95% CI, 0.80-0.99) but more markedly among men on oral hypoglycemic agents (OR, 0.80; 95% CI, 0.74-0.87) and insulin (OR, 0.72; 95% CI, 0.69-0.81). Obese diabetic men (BMI > 30 kg/m(2)) showed a reduced risk (OR, 0.72; 95% CI, 0.65-0.80) compared with men without diabetes. There was a trend of decreasing risk with increasing levels of HbA1c (P < 0.05).

CONCLUSIONS

This nationwide study confirmed a reduced risk of being diagnosed with prostate cancer among men with T2DM, especially for low-risk tumors. An altered hormonal milieu is a plausible explanation, although the possibility of decreased prostate cancer detection among diabetic men cannot be ruled out.

IMPACT

This is the largest study to examine the association between T2DM and prostate cancer accounting for tumor risk group and diabetes treatment.

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

OBJECTIVE

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Prospective study on metabolic factors and risk of prostate cancer

BACKGROUND

There are inconsistent data regarding the association between metabolic factors, separately and combined, and the risk of prostate cancer and death from prostate cancer.

METHODS

In the Metabolic Syndrome and Cancer Project (Me-Can), data on body mass index (BMI); blood pressure; and blood levels of glucose, cholesterol, and triglycerides were collected for 289,866 men. Cox proportional hazard models were used to calculate relative risks (RRs) by exposures in quintiles as well as for z scores (with a mean of 0 and a standard deviation of 1) together with a composite sum of scores to assess the combined effect of metabolic factors. RRs were corrected for random errors in measurement.

RESULTS

During a mean follow-up of 12 years, 6673 men were diagnosed with prostate cancer and 961 died of the disease. Men with high levels of glucose and triglycerides were found to have a decreased risk of prostate cancer: top versus bottom quintile of glucose: RR, 0.82 (95% confidence interval [95% CI], 0.62-1.08; P value for trend = .03) and top versus bottom quintile of triglycerides: RR, 0.88 (95% CI, 0.74-1.04; P value for trend = .001). High BMI, elevated blood pressure, and a high composite z score were found to be associated with an increased risk of death from prostate cancer: top versus bottom quintile of BMI: RR, 1.36 (95% CI, 1.08-1.71); systolic blood pressure: RR, 1.62 (95% CI, 1.07-2.45); and per 1-unit increase of the composite z score: RR, 1.13 (95% CI, 1.03-1.25).

CONCLUSIONS

The authors found no evidence of an association between high levels of metabolic factors and the risk of prostate cancer, but high BMI, elevated blood pressure, and a composite score of all metabolic factors were associated with an increased risk of death from prostate cancer.

Prostate cancer in patients with metabolic syndrome is associated with low grade Gleason score when diagnosed on biopsy

Purpose

Studies on the relationship of metabolic syndrome (MS) and prostate cancer are controversial. We evaluated the association between MS and prostate cancer characteristics in patients who underwent transrectal ultrasound-guided prostate biopsy.

Materials and Methods

From October 2003 to May 2011, patients with a prostate-specific antigen (PSA) value≥4 ng/ml or abnormal digital rectal examination (DRE) result underwent transrectal ultrasound-guided prostate biopsy. MS was diagnosed according to the Adult Treatment Panel III. Clinicopathologic factors including PSA, DRE, prostate volume, age, waist circumference, body mass index (BMI), lipid profiles, fasting blood sugar level, and MS were considered for analysis.

Results

Three hundred fifty-four patients were enrolled (mean age, 68.86±8.95 years; mean PSA, 13.97±20.42 ng/ml). Seventy-five patients (21.2%) had MS and 90 patients (25.4%) were diagnosed as having prostate cancer, including 27 (30%) with MS and 63 (70%) without MS. Total PSA value and prostate volume were significant predictors for prostate cancer. However, MS and BMI were not significantly related to increased cancer risk. Prostate cancer patients with MS had significantly lower Gleason scores (average, 6.63±1.92) than did prostate cancer patients without MS (average, 7.54±1.71; p=0.029).

Conclusions

Presence of MS was associated with a significantly decreased risk of high-grade prostate cancer. A larger, prospective, multicenter investigation is mandatory to clarify the relationship between MS and prostate cancer.

Visceral Fat Accumulation as a Risk Factor for Prostate Cancer

OBJECTIVE

No clear association between obesity or body fat distribution and prostate cancer has been shown. We investigated the relation between visceral fat accumulation as measured by computed tomography (CT) and the occurrence of prostate cancer.

RESEARCH METHODS AND PROCEDURES

We compared body fat distribution assessed by a direct method (CT) in 63 prostate cancer cases with 63 age-matched healthy community controls. A CT scan at the level of the fourth lumbar vertebra was performed in all participants.

RESULTS

Patients presented a significantly higher mean total abdominal fat area (509.2 +/- 226.1 vs. 334.3 +/- 132.9 cm2, p < 0.001), mostly because of a higher mean visceral fat area (VF; 324.7 +/- 145.6 vs. 177.4 +/- 88.4 cm2, p < 0.001) and a significantly higher mean ratio between visceral and subcutaneous fat areas (V/S ratio; 1.8 +/- 0.4 vs. 1.2 +/- 0.4, p < 0.001). A significantly higher risk of prostate cancer was found for participants with higher VF (odds ratio = 4.6; 95% confidence interval = 2.6 to 8.2 per SD increase) and V/S ratio (odds ratio = 6.0; 95% confidence interval = 2.3 to 11.0 per SD increase).

DISCUSSION

These results suggest a role for visceral obesity, quantified by CT, as a risk factor for prostate cancer. The action of the adipocytokines secreted by visceral fat cells, steroid hormone disturbances, and increased levels of insulin or other hormones noted in visceral obesity may explain this association.

Elevated insulin and insulin resistance are associated with the advanced pathological stage of prostate cancer in Korean population

The study was designed to investigate the effect of serum glucose, insulin and insulin resistance on the risk of prostate cancer (CaP) and on the clinicopathological characteristics in Korean men. Subjects were retrospectively recruited from 166 CaP patients underwent radical prostatectomy and 166 age-matched benign prostatic hyperplasia (BPH) patients. The serum was taken on the morning of the day of operation and insulin resistance was assessed by homeostasis model assessment insulin resistance index (HOMA-IR). Men in highest tertile of insulin was associated with 55% reduced odds of CaP than those with the lowest tertile (OR = 0.45, 95% CI = 0.23-0.89, P = 0.022). The patients in highest tertile of insulin had a more than 5.6 fold risk of locally advanced stage than those in the lowest tertile (OR = 5.62, 95% CI = 1.88-16.83, P = 0.002). Moreover, the patients in the highest tertile HOMA-IR group was associated with an increased risk of locally advanced stage than the lowest tertile group (OR = 3.10, 95% CI = 1.07-8.99, P = 0.037). These results suggest that elevated insulin and insulin resistance are associated with the advanced pathological stage of prostate cancer in Korean patients.

Benign prostatic hyperplasia: from bench to clinic

Benign prostatic hyperplasia (BPH) is a prevalent disease, especially in old men, and often results in lower urinary tract symptoms (LUTS). This chronic disease has important care implications and financial risks to the health care system. LUTS are caused not only by mechanical prostatic obstruction but also by the dynamic component of obstruction. The exact etiology of BPH and its consequences, benign prostatic enlargement and benign prostatic obstruction, are not identified. Various theories concerning the causes of benign prostate enlargement and LUTS, such as metabolic syndrome, inflammation, growth factors, androgen receptor, epithelial-stromal interaction, and lifestyle, are discussed. Incomplete overlap of prostatic enlargement with symptoms and obstruction encourages focus on symptoms rather than prostate enlargement and the shifting from surgery to medicine as the treatment of BPH. Several alpha antagonists, including alfuzosin, doxazosin, tamsulosin, and terazosin, have shown excellent efficacy without severe adverse effects. In addition, new alpha antagonists, silodosin and naftopidil, and phosphodiesterase 5 inhibitors are emerging as BPH treatments. In surgical treatment, laser surgery such as photoselective vaporization of the prostate and holmium laser prostatectomy have been introduced to reduce complications and are used as alternatives to transurethral resection of the prostate (TURP) and open prostatectomy. The status of TURP as the gold standard treatment of BPH is still evolving. We review several preclinical and clinical studies about the etiology of BPH and treatment options.

[Interactions of insulin and estrogen in the regulation of cell proliferation and carcinogenesis]

Equilibrium of sexual steroids and metabolic processes has close correlations. Insulin is a potent regulator of human sexual steroid hormone production and modulates their signals at receptor level. Insulin resistance and excessive insulin production provoke hyperandrogenism and estrogen deficiency in women resulting not only in anovulatory dysfunction but also a high risk for cardiovascular diseases and cancer. Physiologic functions of all female organs have higher estrogen demand as compared with men. In healthy women estrogen predominance against androgens is a favor in their reproductive period, which means a strong defense against insulin resistance and its complications. However, in postmenopausal cases the increasing prevalence of insulin resistance and type-2 diabetes associated with estrogen deficiency and androgen excess, result in a gender specific higher risk for precancerous lesions and cancer as compared with men. Estrogen has beneficial effect on the energy metabolism, glucose homeostasis and on the lipid metabolism of liver and of peripheral tissues as well. A moderate or severe decrease in serum estrogen level enhances the prevalence of insulin resistant states. In premenopausal women long or irregular menstrual cycles are predictors for the risk of insulin resistance and type-2 diabetes. Moreover, in postmenopausal estrogen deficient cases elevated fasting glucose, increased body weight and abdominal fat deposition are often observed progressively with age in correlation with an impaired glucose tolerance. In the rare cases of estrogen deficient men severe type-2 diabetes seems to be a characteristic complication. Upon becoming familiar with the cancer risk of insulin resistance and estrogen deficiency, there would be plenty of possibilities for primary cancer prevention. In patients with cancer the treatment of hormonal and metabolic disturbances may become effective adjuvant therapy.

The insulin-like growth factor system, metabolic syndrome, and cardiovascular disease risk

The metabolic syndrome is a combination of metabolic and clinical features that aggregate in individuals and increase cardiovascular disease (CVD) risk considerably. It is believed, although sometimes controversially, that the underlying basis for this syndrome is insulin resistance (IR) and accompanying compensatory hyperinsulinemia. Insulin and insulin-like growth factors (IGFs) have significant homology and interact with differing affinity with the same receptors. Therefore, their actions can be complementary, and this becomes particularly significant clinico-pathologically when their circulating levels are altered. This review of currently available information attempts to answer the following questions: (1) Is there any evidence for changes in the components of the IGF system in individuals with established CVD or with increased CVD risk as with the metabolic syndrome? (2) What are the underlying mechanisms for interactions, if any, between insulin and the IGF system, in the genesis of CVD? (3) Can knowledge of the pathophysiological changes in the IGF system observed in macrosomic newborn infants and growth hormone (GH)-treated children and adults explain some of the observations in relation to the IGF system and the metabolic syndrome? (4) Can the experimental and clinical evidence adduced from the foregoing be useful in designing novel therapies for the prevention, treatment, and assignment of prognosis in metabolic syndrome-associated disease, particularly ischemic heart disease? To answer these questions, we have performed a literature review using bibliographies from PubMed, Medline, and Google Scholar published within the last 10 years. We suggest that IGF-1 levels are reduced consistently in individuals with the metabolic syndrome and its components and in those with ischemic CVD. Such changes are also seen with GH deficiency in which these changes are partially reversible with GH treatment. Furthermore, changes are seen in levels and interactions of IGF-binding proteins in these disorders, and some of these changes appear to be independent of IGF-binding capability and could potentially impact on risk for the metabolic syndrome and CVD. The promising therapeutic implications of these observations are also discussed.

Interplay between insulin resistance and estrogen deficiency as co- activators in carcinogenesis

Both insulin resistance and estrogen deficiency result in complex metabolic disorder based mainly on defective cellular glucose uptake and on an atherogenic serum lipid profile. These alterations may be regarded as high risks for several life-threatening human diseases, such as type-2 diabetes, cardiovascular lesions and malignancies. Insulin resistance and estrogen deficiency are concomitant disorders with mutual interrelationship. Insulin resistance and the compensatory hyperinsulinemia provoke increased androgen synthesis at the expense of decreased estrogen production. Similarly, a moderate or severe decrease in serum estrogen levels enhances the prevalence of insulin resistant states both in men and women. Healthy premenopausal women enjoy the defensive effect of estrogens against metabolic and hormonal disorders. However, even a slight decrease in their circulatory estrogen levels associated with insulin resistance may increase the risk for cancers, particularly in the organs having high estrogen demand (breast, endometrium and ovary). On the other hand, postmenopausal state with profound estrogen deficiency confers high risk for cancers in different organs with either high or moderate estrogen demand. After menopause, hormone replacement therapy improves insulin sensitivity and decreases the enhanced inclination to malignancies in postmenopausal women. Recognition of the thorough interplay between insulin resistance and estrogen deficiency may illuminate many apparently controversial experimental and clinical findings concerning cancer development and therapeutic possibilities. Moreover, their interactions in the initiation and progression of human malignancies may supply new strategies in primary cancer prevention and cancer cure.

Urological aspects of the metabolic syndrome

The metabolic syndrome is common in countries with Western lifestyles. It comprises a number of disorders-including insulin resistance, hypertension and obesity-that all act as risk factors for cardiovascular diseases. Urological diseases have also been linked to the metabolic syndrome. Most established aspects of the metabolic syndrome are linked to benign prostatic hyperplasia (BPH) and prostate cancer. Fasting plasma insulin, in particular, has been linked to BPH and incident, aggressive and lethal prostate cancer. The metabolic syndrome has also been shown to be associated with nonprostatic urological conditions such as male hypogonadism, nephrolithiasis, overactive bladder and erectile dysfunction, although data on these conditions are still sparse. Overall, the results of studies on urological aspects of the metabolic syndrome seem to indicate that BPH and prostate cancer could be regarded as two new aspects of the metabolic syndrome, and that an increased insulin level is a common underlying aberration that promotes both BPH and clinical prostate cancer. Urologists need to be aware of the effect that the metabolic syndrome has on urological disorders and should transfer this knowledge to their patients.

Metabolic complications and increased cardiovascular risks as a result of androgen deprivation therapy in men with prostate cancer

Prostate cancer is one of the most common malignancies in men. Charles Huggins and Clarence V. Hodges reported the androgen dependence of prostate cancer in 1941. That led to the utilization of androgen deprivation therapy as an important therapeutic modality to treat prostate cancer. Androgen deprivation therapy has additional systemic effects that include sexual dysfunction, psychological changes and more important are the metabolic changes. Metabolic changes in particular include insulin resistance, increase fat mass and low-density lipoprotein cholesterol, and induce type 2 diabetes. In this review we will focus on the cardiovascular risk associated with androgen deprivation therapy that includes the mechanisms involved.

Effect of dexamethasone and testosterone treatment on the regulation of insulin-degrading enzyme and cellular changes in ventral rat prostate after castration

Insulin-degrading enzyme (IDE) has been shown to enhance the binding of androgen and glucocorticoid receptors to DNA in the nuclear compartment. Glucocorticoids cause hyperglycaemia, peripheral resistance to insulin and compensatory hyperinsulinaemia. The aim of the present study was to investigate the effect of dexamethasone (D), testosterone (T) and dexamethasone plus testosterone (D + T) on the regulation of IDE and on the remodelling of rat ventral prostate after castration (C). Castration led to a marked reduction in prostate weight (PW). Body weight was significantly decreased in the castrated animals treated with dexamethasone, and the relative PW was 2.6-fold (±0.2) higher in the D group, 2.8-fold (±0.3) higher in the T group and 6.6-fold (±0.6) higher in the D + T group in comparison with the castrated rats. Ultrastructural alterations in the ventral prostate in response to androgen deprivation were restored after testosterone and dexamethasone plus testosterone treatments and partially restored with dexamethasone alone. The nuclear IDE protein level indicated a 4.3-fold (±0.4) increase in castrated rats treated with D + T when compared with castration alone. Whole-cell IDE protein levels increased approximately 1.5-fold (±0.1), 1.5-fold (±0.1) and 2.9-fold (±0.2) in the D, T and D + T groups, respectively, when compared with castration alone. In conclusion, the present study reports that dexamethasone-induced hyperinsulinaemic condition plus exogenous testosterone treatment leads to synergistic effects of insulin and testosterone in the prostatic growth and in the amount of IDE in the nucleus and whole epithelial cell.

Analyzing serum-stimulated prostate cancer cell lines after low-fat, high-fiber diet and exercise intervention

Serum from men undergoing a low-fat, high-fiber diet and exercise intervention has previously been shown to decrease growth and increase apoptosis in serum-stimulated, androgen-dependent LNCaP cells associated with a reduction in serum IGF-I. Here we sought to determine the underlying mechanisms for these anticancer effects. Again, the intervention slowed growth and increased apoptosis in LNCaP cells; responses that were eliminated when IGF-I was added back to the post-intervention samples. The p53 protein content was increased and NFκB activation reduced in the post serum-stimulated LNCaP cells. Similar results were observed when the IGF-I receptor was blocked in the pre-intervention serum. In androgen-independent PC-3 cells, growth was reduced while none of the other factors were changed by the intervention. We conclude that diet and exercise intervention might help prevent clinical PCa as well as aid in the treatment of PCa during the early stages of development.

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

BACKGROUND

Metabolic syndrome (MS) is a set of risk factors that includes obesity and insulin resistance and has been implicated in the development of prostate cancer. Its impact on androgen deprivation therapy (ADT) efficacy has not been studied.

PATIENTS AND METHODS

Retrospective study of prostate cancer patients seen from 1998 to 2005 in a medical oncology clinic. MS, as defined by modified Adult Treatment Panel III criteria, was assessed at the time of initiation of ADT. The study end points were time to prostate-specific antigen (PSA) progression and overall survival (OS) from time of starting ADT.

RESULTS

Eighty-two patients treated with ADT and data to assess for presence of MS were identified. Median age in men with and without MS was 70 years and 49% of the patients evaluated met criteria for MS. Median time to PSA progression for patients with MS was 16 versus 36 months without MS (P=0.003). The median OS for patients with MS was 36.5 months after commencing ADT compared with 46.7 months for those patients without MS (P=0.061).

CONCLUSIONS

This preliminary data suggest that MS is a risk factor for earlier development of castration-resistant prostate cancer and support the need for a prospective evaluation of this finding.

A higher prediagnostic insulin level is a prospective risk factor for incident prostate cancer

A higher insulin level has been linked to the risk of prostate cancer promotion. However, several reports claim that there is no association between a higher insulin level and the risk of incident prostate cancer. In the present report, the insulin hypothesis was tested once more prospectively in men with a benign prostatic disorder. Three hundred and eighty-nine consecutive patients referred with lower urinary tract symptoms without clinical prostate cancer were included during 1994-2002. Follow-up was performed in 2006. Data were obtained from the Swedish National Cancer Register and the Regional Cancer Register, Oncological Centre, Göteborg, Sweden. At this follow-up, 44 of the patients included had developed prostate cancer. Men with prostate cancer diagnosis had a higher systolic (P<0.001) and diastolic blood pressure (P<0.000), were more obese as measured by BMI (P=0.010), waist (P=0.007) and hip measurements (P=0.041) than men who did not have prostate cancer diagnosis at follow-up. These men also had a higher uric acid level (P=0.040), and a higher fasting serum insulin level (P=0.023) than men who did not have prostate cancer diagnosis at follow-up. Following exclusion of T1a/b prostate cancer cases, the difference of the fasting serum insulin level between the groups was still significant (P=0.038). Our data support the hypothesis that a higher insulin level is a promoter of prostate cancer. Moreover, our data suggest that the insulin level could be used as a marker of the risk of developing prostate cancer. The present findings also seem to confirm that prostate cancer is a component of the metabolic syndrome. Finally, our data generate the hypothesis that the metabolic syndrome conceals early prostate cancer.

Diet, physical activity and energy balance and their impact on breast and prostate cancers

Obesity, physical activity status and circulating levels of sex steroid hormones and growth factor proteins are intrinsically linked to energy balance. Epidemiological studies have previously reported associations between these factors and the risk of hormone-related cancers such as prostate and breast cancer in men and postmenopausal women. An increasing number of intervention studies in 'at-risk' populations and cancer survivors are now investigating the effects of lifestyle interventions that promote negative energy balance on circulating levels of sex hormones and growth factor proteins as surrogate markers of cancer risk. Evidence from these studies suggests that lifestyle interventions can improve insulin sensitivity, alter the balance of circulating sex steroid hormones and insulin-like growth factor (IGF) axis proteins (including IGF-1 and the IGF binding proteins 1 and 3) and change the functioning of immune cells in peripheral blood. Such changes could influence the risk of developing hormone-related cancers, as well as having the potential to improve disease-free survival in patients recovering from cancer treatment. However, despite promising results, the methodological quality of most intervention studies has been limited due to small subject numbers, lack of adequate control groups or non-randomised designs and the absence of long-term follow-up measures. More intervention studies with randomised controlled designs, higher numbers of subjects and longer-term follow-up measures are needed to establish which combination of specific dietary and physical activity interventions work best for reducing risk in 'at-risk' populations and survivors, optimal dose-response relationships and the magnitude of change in surrogate markers of cancer risk that is required to induce a protective effect.

An overview of CAM: components and clinical uses

Complementary and alternative medicine (CAM), more recently known as integrative health or integrative medicine, is a diverse field comprising numerous treatments and practitioners of various levels of training. This review defines several of the main CAM modalities and reviews some of the research relevant to their clinical application. The goal is to provide healthcare providers with a basic understanding of CAM to start the incorporation of proven treatments into their clinical practice as well as guide them to working with CAM providers; ultimately, such knowledge is a fundamental part of a collaborative approach to optimal patient health and wellness.

Blood pressure and risk of prostate cancer: Cohort Norway (CONOR)

BACKGROUND

Some studies suggest that raised blood pressure may increase prostate cancer risk. We investigated associations of blood pressure with prostate cancer within the CONOR collaborative cohorts of Norway.

METHODS

Between 1994 and 2003, 82,098 men from ten population-based cohorts in Norway completed standardised questionnaires and physical examinations, including resting blood pressure. The unique 11-digit identification number of Norwegian citizens allowed linkage with the Cancer Registry of Norway.

RESULTS

A total of 78,768 (96%) men who were cancer-free at baseline and average age of 50.3 years (standard deviation, SD: 15.2) were followed up for a mean of 9.15 years. 11.4% of these men used antihypertensive drugs at baseline. During follow-up (1994-2006), 1,974 incident prostate cancers were diagnosed. We found a 4% (95% confidence interval, CI = 0-9%) increased risk of prostate cancer per one SD (18.3 mmHg) increase in systolic blood pressure and similar findings for diastolic blood pressure (hazard ratio, HR: 1.05 per SD; 95% CI = 1.01-1.10). The association was stronger for advanced (HR: 1.16 per SD increase in systolic blood pressure; 95% CI = 1.05-1.27) compared with localised (1.01; 0.95-1.08) prostate cancer (p for heterogeneity in hazard ratios = 0.02).

CONCLUSIONS

Raised blood pressure was associated with an increased risk of prostate cancer, particularly advanced cancers at diagnosis. Understanding the mechanisms underlying these findings may provide biological insights into prostate carcinogenesis. Even if the association was causal, our data suggest that raised blood pressure would account for only 3% of prostate cancers, so the public health impact of this association may be limited.

[Role of hormonal risk factors in oral cancer development]

Male: female ratio of oral cancer cases (OC) is fairly high. Lower rate of female cases as compared with males suggests that some endocrine factors may play role in the development of tumors. The aim of the present study was to clarify the differences of risk factors for OC among male and female cases. In the Oral and Maxillofacial Department of Semmelweis University 2660 OC (2130 males and 530 females) patients were included into the study. Ratio of smoking, alcohol consumption, elevated serum glucose level and menopausal data of the female patients were registered. Concordant to the literary data, smoking and excessive alcohol consumption proved to be an important risk factor for OC both among male and female patients. However, moderate alcohol consumption was a weak risk factor among male and no risk factor among female cases. Elevated serum glucose level was not significant OC risk among male cases, but was a high risk factor among female patients, especially in gingival cancer cases. The female OC cases were near exclusively postmenopausal, and the term between the time of menopause and clinical OC diagnosis was fairly long (average: 17 year). These results suggest that estrogen-deficiency may play an important role in the initiation of OC. In the female OC cases menopause appeared in significantly younger age, and the rate of hysterectomy was also significantly higher as compared with the tumor-free control cases. These data also support the estrogen-deficiency theory of cancer initiation. In postmenopausal female patients both estrogen-deficiency and elevated fasting glucose proved to be risk factors for OC. These results reveal new aspects concerning the etiology of OC and give a possible explanation how smoking-associated tumors may develop even without smoking.

Racial differences in risk of prostate cancer associated with metabolic syndrome

OBJECTIVES

To perform a case-control study to test the association between metabolic syndrome features and prostate cancer. The metabolic syndrome refers to a cluster of conditions serving as risk factors for cardiovascular disease. The metabolic syndrome is prevalent in the United States, and the spectrum of specific features has been shown to differ by race and ethnicity. A number of recent reports have linked metabolic syndrome to prostate cancer; however, most studies have not had racially diverse populations to explore differences in risk.

METHODS

A case-control study was conducted to test the association between metabolic syndrome features and prostate cancer among 637 patients and 244 controls, with African-American men constituting 43% of the study population.

RESULTS

Metabolic syndrome, defined using a modified version of the Adult Treatment Panel III criteria, was marginally associated with an increased risk of prostate cancer in African-American men (odds ratio [OR] 1.71, 95% confidence interval [CI] 0.97-3.01), but not in white men (OR 1.02, 95% CI 0.64-1.62). After stratifying the patients by stage at diagnosis, African-American men with organ-confined disease were more likely to have a history of metabolic syndrome than were the controls (OR 1.82; 95% CI 1.02-3.23), but no association was observed among those with advanced-stage disease (OR 0.93; 95% CI 0.31-2.77). When evaluating the specific features of the metabolic syndrome, obesity was inversely related to prostate cancer among white men (OR 0.51, 95% CI 0.33-0.80) but unrelated to risk among African-American men (OR 1.15, 95% CI 0.70-1.89).

CONCLUSIONS

In the present investigation, the metabolic syndrome was associated with prostate cancer risk in African-American men, but not in white men. The prevalence of this syndrome, coupled with the racial disparity in prostate cancer incidence and outcomes after diagnosis, warrant additional investigation.

Components of the metabolic syndrome and risk of prostate cancer: the HUNT 2 cohort, Norway

BACKGROUND

The metabolic syndrome has been suggested as a unifying link between a "western" lifestyle and an increased prostate cancer risk.

METHODS

We assessed the associations of components of the metabolic syndrome with prostate cancer in a prospective cohort based on 29,364 Norwegian men followed up for prostate cancer incidence and mortality from 1995-1997 to the end of 2005 in the second Nord Trøndelag Health Study (HUNT 2).

RESULTS

During a mean 9.3 years follow-up, 687 incident prostate cancers were diagnosed, and 110 men died from prostate cancer. There was little evidence that baseline BMI, waist circumference, waist-hip ratio, total or HDL-cholesterol, triglycerides, presence of the metabolic syndrome, diabetes, antihypertensive use, or cardiovascular disease were associated with incident or fatal prostate cancer. There was weak evidence that raised blood pressure was associated with an increased risk: for each SD (12 mm) increase in diastolic blood pressure, there was an 8% (95% CI = 1-17%; p = 0.04) increased risk of incident prostate cancer.

CONCLUSIONS

We found little evidence to support the hypothesis that the metabolic syndrome or its components explains higher prostate cancer mortality rates in countries with a "western" diet and lifestyle. The positive association of blood pressure with prostate cancer warrants further investigation.

Biological mediators of effect of diet and stress reduction on prostate cancer

BACKGROUND

A 6-month pilot intervention trial was conducted to determine whether adoption of a plant-based diet, reinforced by stress reduction, could reduce the rate of prostate-specific antigen (PSA) increase, a marker of disease progression, in asymptomatic, hormonally untreated patients experiencing consistently increasing PSA levels after surgery or radiation.

METHODS

A pre-post design was used to examine (1) the effect of intervention on potential mediators of disease progression, including body composition and weight-related biomarkers (sex steroid hormones and cytokines), and (2) whether changes in these variables were associated with change in rate of PSA increase. The baseline rate of PSA increase (from the time of posttreatment recurrence to the start of intervention) was ascertained from medical records. Body composition and biomarkers were assessed at baseline (prior to intervention), during the intervention (3 months), and at the end of the intervention (6 months). Changes in body composition and biomarkers were determined and compared with rates of PSA increase over the corresponding time intervals.

RESULTS

There was a significant reduction in waist-to-hip ratio (P=.03) and increase in circulating sex hormone binding globulin (P=.04). The rate of PSA increase decreased from the preintervention period (PSA slope=0.059) to the period from 0 to 3 months (PSA slope=0.002, P<.01) and increased slightly, although not significantly, from 0 to 3 months to the period from 3 to 6 months (0.029, P=.43).

CONCLUSIONS

Adoption of a plant-based diet and stress reduction may reduce central adiposity and improve the hormonal milieu in patients with recurrent PC. Changes in the rate of increase in PSA were in the same direction as changes in waist-to-hip ratio and opposite those of sex hormone binding globulin, raising the possibility that the effect of the intervention may have been mediated, in part, by these variables.