Reduced Prostate Cancer Incidence Research Articles

Effect of aspirin on incidence, recurrence, and mortality in prostate cancer patients: integrating evidence from randomized controlled trials and real-world studies.

Aspirin has been suggested to reduce the risk of cancer. However, previous studies have been inconsistent regarding the relationship between aspirin use and the risk of occurrence of prostate cancer (PCa). The purpose of this study was to assess the effect of aspirin on clinical outcomes in patients with PCa in a meta-analysis and to explore the possible dose-response relationship. A systematic literature search was conducted in 10 electronic databases and 4 registries. The combined relative risks (RRs) were calculated using a random-effects model with 95% confidence interval (CIs) to assess the effect of aspirin on the risk of PCa. Relevant subgroup analyses and sensitivity analyses were performed. The across studies results show that aspirin use associated with lower incidence of PCa (RR: 0.96, 95% CI: 0.95-0.98), and reduced mortality (RR: 0.88, 95% CI: 0.82-0.95). The results of the subgroup analysis indicated that both cohort and population studies in the Americas showed a reduction in PCa incidence and mortality with aspirin use. A linear correlation was observed between dosage/duration of aspirin use and its protective effect. Additionally, post-diagnosis aspirin use was associated with decreased risk of PCa mortality. This meta-analysis revealed an independent correlation between the use of aspirin and reductions in both the incidence and mortality rates of PCa. However, randomized controlled trials did not find any association between aspirin use and PCa. Furthermore, the impact of aspirin on PCa occurrence was found to be dependent on both dosage and duration.

Hormonal and genotoxic estrogen-androgen carcinogenesis in the NBL rat prostate: A role for aromatase.

Androgens are generally thought to cause prostate cancer, but the data from animal studies suggest that they must be aromatized to estrogen and act in concert with genotoxic estrogen metabolites. The objective of this study was to determine whether treatment with testosterone (T) combined with a nonestrogenic estrogen metabolite and a nongenotoxic estrogenic compound would all be necessary and sufficient for the induction of a high incidence of prostate cancer in the susceptible NBL rat strain. NBL rats were treated with low-dose testosterone via slow-release Silastic implants and with the marginally estrogenic genotoxic catechol estrogen 4-hydroxyestradiol (4OH-E2) and the nongenotoxic estrogen 2-fluoroestradiol (2F-E2) and in one experiment the aromatase inhibitor letrozole via custom-made slow-release pellets. Animals were euthanized 52 weeks after implantation and their pituitaries and prostate complexes weighed and fixed in formalin. Hematoxylin and eosin (H&E)-stained step sections were prepared and examined microscopically for proliferative lesions. Animals treated with 2F-E2, with or without the other compounds, had enlarged pituitaries demonstrating its estrogenicity. Animals treated with T, with or without the other compounds, had enlarged prostates consistent with its androgenicity. Rats treated with T plus 2F-E2 and 4OH-E2 developed a high incidence of prostatic cancer (89%), while, surprisingly, rats treated with T plus only 2F-E2 also had a high incidence of prostate cancer (95%) contradicting our initial hypothesis. To test whether the formation of E2 from T by aromatase could lead to estrogen genotoxicity and prostate carcinogenesis we then rats treated with T and 2F-E2 also with letrozole and found that it reduced prostate cancer incidence by about 50%. These findings indicate that long-term treatment with a nongenotoxic estrogen (2F-E2) and T as well as uninhibited prostatic aromatase activity generating genotoxic E2 are all required for induction of a high incidence of prostatic adenocarcinomas in NBL rats. These and previous data indicate that androgen receptor-mediated action, estrogen receptor mediation, and estrogen genotoxicity are all required and sufficient for hormonal carcinogenesis in the NBL rat prostate. Interference with the estrogen genotoxicity is a potential approach to prostate cancer chemoprevention.

Broccoli sprouts delay prostate cancer formation and decrease prostate cancer severity with a concurrent decrease in HDAC3 protein expression in TRAMP mice

Background: Cruciferous vegetables have been associated with the chemoprevention of cancer. Epigenetic regulators have been identified as important targets for prostate cancer chemoprevention. Treatment of human prostate cancer cells with sulforaphane (SFN), a chemical from broccoli and broccoli sprouts, inhibits epigenetic regulators such as histone deacetylase (HDAC) enzymes, but it is not known whether consumption of a diet high in broccoli sprouts impacts epigenetic mechanisms in an in vivo model of prostate cancer. Objective: In the transgenic adenocarcinoma of the mouse prostate (TRAMP) model, we tested the hypothesis that a broccoli sprout diet suppresses prostate cancer, inhibits HDAC expression, alters histone modifications, and changes the expression of genes regulated by HDACs. Methods: TRAMP mice were fed a 15% broccoli sprout, or control AIN93G diet; tissue samples were collected at 12 and 28 weeks of age. Results: Mice fed broccoli sprouts had detectable levels of SFN metabolites in liver, kidney, colon, and prostate tissues. Broccoli sprouts reduced prostate cancer incidence, and progression to invasive cancer by 11- and 2.4-fold at 12 and 28 weeks of age, respectively. There was a significant decline in HDAC3 protein expression in the epithelial cells of prostate ventral and anterior lobes at 12 weeks. Broccoli sprout consumption also decreased histone H3 lysine 9 tri-methylation in the ventral lobe (12 week), and decreased histone H3 lysine 18 acetylation in all prostate lobes (28 weeks). A decline in p16 mRNA levels, a gene regulated by HDAC3, was associated with broccoli sprouts consumption, but no significant changes were noted at the protein level. Conclusions: Broccoli sprout intake caused a decline in prostate cancer occurrence and HDAC3 protein expression in the prostate, extending prior work that implicated loss of HDAC3/corepressor interactions as a key preventive mechanism by SFN in vivo.

Genetically Predicted Circulating Concentrations of Alanine and Alanine Aminotransferase Were Associated with Prostate Cancer Risk.

Prostate cancer is one of the leading malignancies in men worldwide. Previous observational studies have linked amino acids and transaminase with altered risk of prostate cancer. However, whether these associations were causal remained unclear. Therefore, we conducted a Mendelian randomization (MR) to assess their potential causal associations. Summary-level data for prostate cancer were obtained from a meta-analysis of genome-wide association studies (GWAS) including 79,148 prostate cancer cases and 61,106 controls of European descent. Instrumental variables (IVs) of amino acids and alanine aminotransferase (ALT) were obtained from a GWAS of 86,507 European individuals and a GWAS of 312,572 participants from the UK Biobank, respectively. MR analyses were performed using inverse-variance-weighted (IVW), likelihood-based, MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO) test and MR-Egger regression. Genetically predicted circulating concentrations of alanine were associated with an increased risk of prostate cancer (odds ratio (OR): 1.16, 95% confidence interval (CI): 1.01-1.33, P=0.037 by IVW). Consistently, genetically predicted ALT was inversely associated with the risk of prostate cancer (OR: 0.43, 95% CI: 0.27-0.68, P=3.28×10-4 by IVW). MR-Egger regression did not indicate evidence of directional pleiotropy and sensitivity analyses yielded consistent associations. Our study revealed that genetically predicted circulating alanine and ALT levels were associated with an altered risk of prostate cancer, suggesting their potential roles in the development of prostate cancer. Whether targeting alanine, ALT or its downstream effectors are helpful in reducing prostate cancer incidence warrants further investigation.

Patterns of finasteride and dutasteride use in the prostate, lung, colorectal and ovarian (PLCO) cancer screening trial cohort: effects of socio-demographic factors and a black box warning

Background: Five-alpha reductase inhibitors (5-ARIs), specifically finasteride and dutasteride, have been shown to significantly reduce prostate cancer incidence. However, these agents were also associated with a significant increase in the detection of high-grade prostate cancer leading to an FDA black box warning in 2011. Little is known about the effect of this warning on the subsequent use of these 5-ARIs. The purpose of this analysis was to assess use patterns of finasteride and dutasteride before and after the black box warning. Methods: This cohort study evaluated men enrolled in the Prostate, Lung, Colorectal and Ovarian (PLCO) screening trial who had ≥12 months of Medicare Part D coverage from 2008 to 2015, and had not been diagnosed with prostate cancer through 2007. Socio-demographic factors and benign prostatic hyperplasia (BPH) status were ascertained from follow-up questionnaires, while medication use was ascertained from linkage to Medicare Part D claims data. Results: Of 14,833 eligible men, 88.7% identified as non-Hispanic white, 1.7% as African-American, 5.2% as Asian/Pacific Islander and 1.7% as Hispanic. The median age was 72 years; 41.8% reported a BPH diagnosis. Only 13.6% and 4% of the population took finasteride or dutasteride, respectively, at any time from 2008 to 2015. During this period, finasteride use significantly increased from 3.6% to 9.7% and was highest among men with BPH; dutasteride use remained low and decreased from 2.8% to 1.9%. Conclusions: Finasteride use significantly increased after the FDA’s 2011 black box warning, while dutasteride use remained low and steady throughout the study period.

Impacts of the COVID-19 pandemic on early detection of prostate cancer in Australia.

Impacts of the COVID-19 pandemic on early detection of prostate cancer in Australia.

Altering phosphoinositides in high-fat diet-associated prostate tumor xenograft growth.

The metabolic reprogramming of phospholipids may affect intracellular signal transduction pathways. A high‐fat diet (HFD) is attributed to prostate cancer (PCa) progression, but the expression pattern and role of phospholipids in HFD‐mediated PCa progression remains unclear. In this study, HFD enhanced LNCaP xenograft tumor growth by upregulating the phosphatidylinositol (PI) 3‐kinase (PI3K)/AKT signaling pathway. A lipidomic analysis using xenograft tumors showed that phosphoinositides, especially PI (3,4,5)‐trisphosphate (PIP3), including several species containing C38:4, C38:3, and C40:4 fatty acids, increased in the HFD group compared to control. Fatty acid synthase (FASN) was significantly upregulated in xenograft tumors under HFD in both gene and protein levels. PCa cell growth was significantly inhibited through the decreased AKT signaling pathway by treatment with cerulenin, a chemical FASN inhibitor, which also downregulated PIP, PIP2, and PIP3 but not PI. Thus, dietary fat influences PCa progression and alters phosphoinositides, especially PIP3, a critical player in the PI3K/AKT pathway. These results may offer appropriate targets, such as FASN, for dietary intervention and/or chemoprevention to reduce PCa incidence and progression.

Racial disparity in prostate cancer in the African American population with actionable ideas and novel immunotherapies.

BackgroundAfrican Americans (AAs) in the United States are known to have a higher incidence and mortality for Prostate Cancer (PCa). The drivers of this epidemiological disparity are multifactorial, including socioeconomic factors leading to lifestyle and dietary issues, healthcare access problems, and potentially tumor biology.Recent findingsAlthough recent evidence suggests once access is equal, AA men have equal outcomes to Caucasian American (CA) men, differences in PCa incidence remain, and there is much to do to reverse disparities in mortality across the USA. A deeper understanding of these issues, both at the clinical and molecular level, can facilitate improved outcomes in the AA population. This review first discusses PCa oncogenesis in the context of its diverse hallmarks before benchmarking key molecular and genomic differences for PCa in AA men that have emerged in the recent literature. Studies have emphasized the importance of tumor microenvironment that contributes to both the unequal cancer burden and differences in clinical outcome between the races. Management of comorbidities like obesity, hypertension, and diabetes will provide an essential means of reducing prostate cancer incidence in AA men. Although requiring further AA specific research, several new treatment strategies such as immune checkpoint inhibitors used in combination PARP inhibitors and other emerging vaccines, including Sipuleucel‐T, have demonstrated some proven efficacy.ConclusionGenomic profiling to integrate clinical and genomic data for diagnosis, prognosis, and treatment will allow physicians to plan a “Precision Medicine” approach to AA men. There is a pressing need for further research for risk stratification, which may allow early identification of AA men with higher risk disease based on their unique clinical, genomic, and immunological profiles, which can then be mapped to appropriate clinical trials. Treatment options are outlined, with a concise description of recent work in AA specific populations, detailing several targeted therapies, including immunotherapy. Also, a summary of current clinical trials involving AA men is presented, and it is important that policies are adopted to ensure that AA men are actively recruited. Although it is encouraging that many of these explore the lifestyle and educational initiatives and therapeutic interventions, there is much still work to be done to reduce incidence and mortality in AA men and equalize current racial disparities.

Genetically predicted levels of circulating cytokines and prostate cancer risk: A Mendelian randomization study.

Inflammation is considered to play a pivotal role in the pathogenesis of cancer, and observational studies have reported a relationship between circulating inflammation markers and the risk of prostate cancer. Using summary data of >140 000 individuals, two-sample Mendelian randomization (MR) analyses were performed to evaluate whether circulating levels of 27 cytokines and growth factors have a causal effect on the risk of developing prostate cancer. Genetically predicted elevated levels of monocyte chemotactic protein-1 (MCP-1) were associated with an increased risk of prostate cancer (odds ratio (OR) per 1 SD increase = 1.06, 95% confidence interval (CI): 1.04-1.09) at Bonferroni-adjusted level of significance (P < 1.85 × 10-3). Results were stable across sensitivity analyses, and there was no evidence of directional pleiotropy. Under MR assumptions, our findings suggested a risk-increasing effect of circulating MCP-1 levels on prostate cancer. Whether targeting MCP-1 or its downstream effectors are useful in reducing prostate cancer incidence needs further investigation.

Impact of US population demographic changes on projected incident cancer cases from 2019 to 2045 in three major cancer types.

e19044 Background: The United States (US) Census Bureau has forecasted an unprecedented shift in the US demographics by 2045, in which there will be no single majority race/ethnicity. Due to well-characterized health disparities among different races/ethnicities in oncology and projected demographic changes, it is of interest to assess changes in the burden of three most frequent cancers: breast cancer (BC) for women, prostate cancer (PC) for men, and colorectal cancer (CRC) for both genders between 2019 and 2045. Methods: Historical age-adjusted rates (AARs) for BC in women, PC in men, and CRC in patients of all ages and stratified by race/ethnicity were collected from the SEER 18 database for 2000-15 period. AARs for cancers of interest were analyzed in Joinpoint Regression Program to obtain an average annual percent change (AAPC) for 2000-15. AARs were then projected to 2045 by assuming the rate behavior is equal to the AAPC. Projected absolute cases per 100,000 were generated by multiplying projected AARs with the associated projected population, retrieved from the US Census Bureau 2017 National Population Projects, and dividing by 100,000. The absolute change in projected patient numbers of cancer cases by race/ethnicity were assessed between 2019 and 2045. Results: From 2019 to 2045, a decrease of 4% is expected in the White Non-Hispanic (WNH) population while the Black (B), Hispanic (H), and Asian/Pacific Islander (API) populations are projected to increase 24%, 54%, and 57%, respectively. In the same time period, the projected number of BC incident cases for women of all ages decreased by 1% in WNH while the B, WH, and API populations were projected to increase 72%, 98%, and 120%, respectively. In both genders of all ages, a 39% and 17% reduction in the number of CRC incident cases in the WNH and B is expected compared to a 61% and 11% increase in the WH and API populations, respectively. Given observed reduction in PC incidence, especially in men 65+, the number of incident PC cases is projected to decrease by 2045 for all included races/ethnicities. Conclusions: Among racial and ethnic minorities, an increase in the number of BC and CRC cases is expected between 2019 and 2045. Projected decrease in PC cases is likely a result of decrease in incidence rates between 2010 and 2015 and should be assessed as new data become available. Currently, racial and ethnic minorities comprise &lt; 20% of patients enrolled in clinical trials, demonstrating the need to understand biologic and social underpinnings of disparities in clinical outcomes in underrepresented groups.

Organoids Increase the Predictive Value of in vitro Cancer Chemoprevention Studies for in vivo Outcome.

Epidemiological and preclinical data suggest that antioxidants are protective against prostate cancer whose pathogenesis has been linked to oxidative stress. However, the selenium and vitamin E Cancer Prevention Trial (SELECT), found no efficacy for selenium in reducing prostate cancer incidence while vitamin E was associated with an increased risk of the disease. These results have called in to question the models used in preclinical chemoprevention efficacy studies and their ability to predict in vivo outcomes. Chemoprevention agents have traditionally been tested on two dimensional monolayer cultures of cell lines derived from advanced prostate cancers. But as SELECT demonstrates, results from advanced disease models were not predictive of the outcome of a primary chemoprevention trial. Additionally, lack of cell-matrix interactions in two dimensional cultures results in loss of biochemical and mechanical cues relevant for native tissue architecture. We use recent findings in three dimensional organoid cultures that recapitulated the SELECT trial results to argue that the organoid model could increase the predictive value of in vitro studies for in vivo outcomes.

A natural history model for planning prostate cancer testing: Calibration and validation using Swedish registry data.

Recent prostate cancer screening trials have given conflicting results and it is unclear how to reduce prostate cancer mortality while minimising overdiagnosis and overtreatment. Prostate cancer testing is a partially observable process, and planning for testing requires either extrapolation from randomised controlled trials or, more flexibly, modelling of the cancer natural history. An existing US prostate cancer natural history model (Gulati et al, Biostatistics 2010;11:707-719) did not model for differences in survival between Gleason 6 and 7 cancers and predicted too few Gleason 7 cancers for contemporary Sweden. We re-implemented and re-calibrated the US model to Sweden. We extended the model to more finely describe the disease states, their time to biopsy-detectable cancer and prostate cancer survival. We first calibrated the model to the incidence rate ratio observed in the European Randomised Study of Screening for Prostate Cancer (ERSPC) together with age-specific cancer staging observed in the Stockholm PSA (prostate-specific antigen) and Biopsy Register; we then calibrated age-specific survival by disease states under contemporary testing and treatment using the Swedish National Prostate Cancer Register. After calibration, we were able to closely match observed prostate cancer incidence trends in Sweden. Assuming that patients detected at an earlier stage by screening receive a commensurate survival improvement, we find that the calibrated model replicates the observed mortality reduction in a simulation of ERSPC. Using the resulting model, we predicted incidence and mortality following the introduction of regular testing. Compared with a model of the current testing pattern, organised 8 yearly testing for men aged 55–69 years was predicted to reduce prostate cancer incidence by 14% and increase prostate cancer mortality by 2%. The model is open source and suitable for planning for effective prostate cancer screening into the future.

In Vitro Anticancer Properties of Table Grape Powder Extract (GPE) in Prostate Cancer.

Although the link between diet and cancer is complex, epidemiological data confirm that diet is a risk factor for prostate cancer and indicate a reduced prostate cancer incidence associated with a diet rich in vegetables and fruits. Because of the known protective effect of grape seed extract (GSE) against prostate cancer, we evaluated the effects of grape powder extract (GPE) on cell viability, proliferation, and metastatic capability. Importantly, we explored the possible novel mechanism of GPE through metastasis-associated protein 1 (MTA1) downregulation in prostate cancer, since our previous studies indicated resveratrol (Res)- and pterostilbene (Pter)-induced MTA1-mediated anticancer activities in prostate cancer. We found that GPE inhibited the cell viability and growth of prostate cancer cells only at high 100 μg/mL concentrations. However, at low 1.5–15 μg/mL concentrations, GPE significantly reduced the colony formation and wound healing capabilities of both DU145 and PC3M cells. Moreover, we found that GPE inhibited MTA1 in a dose-dependent manner in these cells, albeit with considerably less potency than Res and Pter. These results indicate that stilbenes such as Res and Pter specifically and potently inhibit MTA1 and MTA1-associated proteins compared to GPE, which contains low concentrations of Res and mainly consists of other flavonoids and anthocyanidins. Our findings support continued interest in GPE as a chemopreventive and anti-cancer agent against prostate cancer but also emphasize the unique and specific properties of stilbenes on MTA1-mediated anticancer effects on prostate cancer.

Intake of Non-steroidal Anti-inflammatory Drugs and the Risk of Prostate Cancer: A Meta-Analysis

Background: Epidemiological evidences regarding the association between the use of non-steroidal anti-inflammatory drugs (NSAIDs) and the risk of prostate cancer (PC) is still controversial. Therefore, we conducted a meta-analysis to explore the controversy that exists.Methods: Electronic databases including Medline, EMBASE, Web of Science, Cochrane Library, BIOSIS, Scopus, CBM, CNKI, WANFANG, and CQVIP were used to search for and identify eligible studies published until December 31, 2017. Pooled effect estimates for the relative risk (RR) were computed through fixed-effects or random-effects models as appropriate. Publication bias was evaluated by Egger's and Begg's tests and potential sources of heterogeneity were investigated in subgroup analyses.Results: A total of 43 observational studies were eligible for this meta-analysis. A protective effect was identified for the intake of any NSAIDs on the risk of PC (pooled RR = 0.89, 95% CI = 0.81–0.98). Moreover, the long-term intake of NSAIDs (≥5 years rather than ≥4 years) was associated with reduced PC incidence (pooled RR = 0.882, 95% CI = 0.785–0.991). Aspirin intake was also associated with a 7.0% risk reduction of PC (pooled RR = 0.93, 95% CI = 0.89–0.96). The inverse association became stronger for advanced PC and PC with a Gleason score ≥7 compared to the association with total PC. Interestingly, it was the daily dose (≥1 pill/day) rather than, long-term aspirin intake (≥4 or ≥5 years) that was associated with reduced PC incidence (pooled RR = 0.875, 95% CI = 0.792–0.967). The pooled effects for non-aspirin NSAIDs demonstrated no significantly adverse or beneficial effects on total PC, advanced PC, or PC with Gleason score ≥7, though all pooled RRs were >1.Conclusions: Our findings suggested a protective effect of the intake of any NSAIDs on the risk of PC, especially in those who took the NSAIDs for a long period. Moreover, aspirin intake was also associated with a decreased risk of PC, and there was a dose related association between aspirin intake and the risk of PC, while no significant effects of long-term aspirin intake were found on the PC incidence.

Broccoli Sprouts Delay Prostate Cancer Formation and Decrease Prostate Cancer Severity with a Concurrent Decrease in HDAC3 Protein Expression in Transgenic Adenocarcinoma of the Mouse Prostate (TRAMP) Mice

BackgroundCruciferous vegetables have been associated with the chemoprevention of cancer. Epigenetic regulators have been identified as important targets for prostate cancer chemoprevention. Treatment of human prostate cancer cells with sulforaphane (SFN), a chemical from broccoli and broccoli sprouts, inhibits epigenetic regulators such as histone deacetylase (HDAC) enzymes, but it is not known whether consumption of a diet high in broccoli sprouts impacts epigenetic mechanisms in an in vivo model of prostate cancer. ObjectiveIn the transgenic adenocarcinoma of the mouse prostate (TRAMP) model, we tested the hypothesis that a broccoli sprout diet suppresses prostate cancer, inhibits HDAC expression, alters histone modifications, and changes the expression of genes regulated by HDACs. MethodsTRAMP mice were fed a 15% broccoli sprout or control AIN93G diet; tissue samples were collected at 12 and 28 wk of age. ResultsMice fed broccoli sprouts had detectable amounts of SFN metabolites in liver, kidney, colon, and prostate tissues. Broccoli sprouts reduced prostate cancer incidence and progression to invasive cancer by 11- and 2.4-fold at 12 and 28 wk of age, respectively. There was a significant decline in HDAC3 protein expression in the epithelial cells of prostate ventral and anterior lobes at age 12 wk. Broccoli sprout consumption also decreased histone H3 lysine 9 trimethylation in the ventral lobe (age 12 wk), and decreased histone H3 lysine 18 acetylation in all prostate lobes (age 28 wk). A decline in p16 mRNA levels, a gene regulated by HDAC3, was associated with broccoli sprout consumption, but no significant changes were noted at the protein level. ConclusionsBroccoli sprout intake was associated with a decline in prostate cancer occurrence and HDAC3 protein expression in the prostate, extending prior work that implicated loss of HDAC3/ corepressor interactions as a key preventive mechanism by SFN in vivo.

Investigating the possible causal role of coffee consumption with prostate cancer risk and progression using Mendelian randomization analysis.

Coffee consumption has been shown in some studies to be associated with lower risk of prostate cancer. However, it is unclear if this association is causal or due to confounding or reverse causality. We conducted a Mendelian randomisation analysis to investigate the causal effects of coffee consumption on prostate cancer risk and progression. We used two genetic variants robustly associated with caffeine intake (rs4410790 and rs2472297) as proxies for coffee consumption in a sample of 46,687 men of European ancestry from 25 studies in the PRACTICAL consortium. Associations between genetic variants and prostate cancer case status, stage and grade were assessed by logistic regression and with all‐cause and prostate cancer‐specific mortality using Cox proportional hazards regression. There was no clear evidence that a genetic risk score combining rs4410790 and rs2472297 was associated with prostate cancer risk (OR per additional coffee increasing allele: 1.01, 95% CI: 0.98,1.03) or having high‐grade compared to low‐grade disease (OR: 1.01, 95% CI: 0.97,1.04). There was some evidence that the genetic risk score was associated with higher odds of having nonlocalised compared to localised stage disease (OR: 1.03, 95% CI: 1.01, 1.06). Amongst men with prostate cancer, there was no clear association between the genetic risk score and all‐cause mortality (HR: 1.00, 95% CI: 0.97,1.04) or prostate cancer‐specific mortality (HR: 1.03, 95% CI: 0.98,1.08). These results, which should have less bias from confounding than observational estimates, are not consistent with a substantial effect of coffee consumption on reducing prostate cancer incidence or progression.

Metformin for Reducing Racial/Ethnic Difference in Prostate Cancer Incidence for Men with Type II Diabetes.

Racial/ethnic disparity in prostate cancer is under studied in men with diabetes who are at a higher risk of aggressive prostate cancer. This study assessed the race/ethnic disparity in prostate cancer incidence for men with type II diabetes (T2D) and whether the impact of metformin on prostate cancer incidence varied by race/ethnicity. We conducted a retrospective study in 76,733 male veterans with T2D during 2003 to 2012. Cox proportional hazards model adjusting for covariates and propensity scores of metformin use and race/ethnic group membership was utilized to compute the HR of prostate cancer incidence associated with race/ethnicity and compare HR associated with metformin use between race/ethnic groups. Mean follow-up was 6.4 ± 2.8 years; 7% were Hispanics; 17% were African Americans (AA); mean age was 67.8 ± 9.8 years; 5.2% developed prostate cancer; and 38.9% used metformin. Among these diabetic men without metformin use, prostate cancer incidence was higher in Hispanics and AA than in non-Hispanic White (NHW). Use of metformin alone or metformin + statins was associated with a greater prostate cancer incidence reduction in Hispanics compared with NHW, but not between AA and NHW. Use of metformin + finasteride was associated with a greater prostate cancer incidence reduction in Hispanics and AA compared with NHW. Our results suggested that metformin treatment could be a potential strategy to reduce prostate cancer incidence in the minority populations who are at high risk for fatal prostate cancer. It will be important to further examine the pleiotropic effects of metformin in multi-race/ethnic prospective studies to better inform clinical management and potentially reduce racial/ethnic disparity in prostate cancer incidence among diabetic men. Cancer Prev Res; 9(10); 779-87. ©2016 AACR.

Statin derivatives as therapeutic agents for castration-resistant prostate cancer

Despite recent advances in modern medicine, castration-resistant prostate cancer remains an incurable disease. Subpopulations of prostate cancer cells develop castration-resistance by obtaining the complete steroidogenic ability to synthesize androgens from cholesterol. Statin derivatives, such as simvastatin, inhibit cholesterol biosynthesis and may reduce prostate cancer incidence as well as progression to advanced, metastatic phenotype. In this study, we demonstrate novel simvastatin-related molecules SVA, AM1, and AM2 suppress the tumorigenicity of prostate cancer cell lines including androgen receptor-positive LNCaP C-81 and VCaP as well as androgen receptor-negative PC-3 and DU145. This is achieved through inhibition of cell proliferation, colony formation, and migration as well as induction of S-phase cell-cycle arrest and apoptosis. While the compounds effectively block androgen receptor signaling, their mechanism of inhibition also includes suppression of the AKT pathway, in part, through disruption of the plasma membrane. SVA also possess an added effect on cell growth inhibition when combined with docetaxel. In summary, of the compounds studied, SVA is the most potent inhibitor of prostate cancer cell tumorigenicity, demonstrating its potential as a promising therapeutic agent for castration-resistant prostate cancer.

Number of Screening Rounds and Postscreening Prostate Cancer Incidence: Results from the Finnish Section of the European Randomized Study of Screening for Prostate Cancer Study

BackgroundThe multicenter European Randomized Study of Screening for Prostate Cancer has shown a 21% reduction in prostate cancer (PC) mortality by prostate-specific antigen-based screening, with substantial overdiagnosis. In the present study, we analyzed the incidence of PC after screening in relation to the number of screening rounds attended in the Finnish section of the trial. ObjectiveTo evaluate the possible reduction in PC incidence following completed screening cycles in relation to the number of screening rounds attended. Design, setting, and participantsThe participants in the screening arm of the Finnish screening trial (29 298 men) were divided into subgroups of men who had participated at one, two, or three screening rounds. A reference group was formed of the 43 151 men in the control arm by selecting age-matched controls for each subgroup of the screening participants. PC cases diagnosed after screening were identified from the Finnish Cancer Registry until the end of 2011. Follow-up of the screened men started 12 mo (365 d) after the last screening attendance and a similar date was assigned to the men in the control arm. Results and limitationsA total of 1514 new PCs cases (cumulative incidence 5.2%) were diagnosed among the screened men after the last screening attendance. In the reference group formed from the control arm, 2683 cases (6.2%) occurred. The hazard ratio (HR) for PC among nonparticipants in the screening arm was 0.89 (95% confidence interval [CI] 0.79–0.99) compared with their controls. Among participants, the HR in those who participated once was 1.39 (95% CI 1.22–1.57), among men who participated twice the HR was 0.97 (95% CI 0.86–1.10), and among men screened three times the HR was 0.57 (95% CI 0.49–0.68). A limitation of the study was that the comparison by attendance is not based on randomization. ConclusionsThe postscreening PC incidence is reduced after attending three screening rounds, but not after only one or two rounds. Thus, the increased cancer detection at screening is compensated by a subsequent risk reduction only after repeated screening cycles. Patient summaryThe results of the study indicate that at least three prostate-specific antigen-based screening cycles are needed to reduce subsequent prostate cancer incidence.

Serum Metabolomic Response to Long-Term Supplementation withall-rac-α-Tocopheryl Acetate in a Randomized Controlled Trial

Background. The Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study, a randomized controlled cancer prevention trial, showed a 32% reduction in prostate cancer incidence in response to vitamin E supplementation. Two other trials were not confirmatory, however. Objective. We compared the change in serum metabolome of the ATBC Study participants randomized to receive vitamin E to those who were not by randomly selecting 50 men from each of the intervention groups (50 mg/day all-rac-α-tocopheryl acetate (ATA), 20 mg/day β-carotene, both, placebo). Methods. Metabolomic profiling was conducted on baseline and follow-up fasting serum (Metabolon, Inc.). Results. After correction for multiple comparisons, five metabolites were statistically significantly altered (β is the change in metabolite level expressed as number of standard deviations on the log scale): α-CEHC sulfate (β = 1.51, p = 1.45 × 10−38), α-CEHC glucuronide (β = 1.41, p = 1.02 × 10−31), α-tocopherol (β = 0.97, p = 2.22 × 10−13), γ-tocopherol (β = −0.90, p = 1.76 × 10−11), and β-tocopherol (β = −0.73, p = 9.40 × 10−8). Glutarylcarnitine, beta-alanine, ornithine, and N6-acetyllysine were also decreased by ATA supplementation (β range 0.40 to −0.36), but not statistically significantly. Conclusions. Comparison of the observed metabolite alterations resulting from ATA supplementation to those in other vitamin E trials of different populations, dosages, or formulations may shed light on the apparently discordant vitamin E-prostate cancer risk findings.