Serum vitamin D and risk of prostate cancer in a case-control analysis nested within the European Prospective Investigation into Cancer and Nutrition (EPIC)

Evaluation of normal range of serum 25 hydroxyvitamin d in iraqi healthy adults: demographic and socioeconomic effects

OBJECTIVE

Aim: To determine the normal range of serum levels of total 25(OH)VD in Iraqi healthy adult subjects and to relate its level with demographic profile and socioeconomic status..

PATIENTS AND METHODS

Materials and Methods: This cross sectional study was carried out at Iraq and the samples were collected during the period from August 2019 to January 2020. It included 649 adult subjects apparently healthy, from three governorates (Baghdad, Al-Anbar and Al-Basrah), Investigations included serum measurement of total 25(OH)D in all included individuals by using ELISA technique. Age, gender, marital state, blood pressure, smoking, sunshine exposure (%), hours of exposure/day, percentage of body surface area exposed, body mass index (BMI) subgroups, waist circumference (WC) subgroups, diet type, sport type and time, geographic factor (governorate) were measured and / or calculated and the levels of 25(OH)D were studied according to each of these factors.

RESULTS

Results: The mean ± SD level of 25(OH)D in total (n=649) studied Iraqi subjects was (16.29 ± 8.22 ng/ml), with women were significantly deficient than men (15.76 ± 6.89 ng/ml, 17.14 ± 6.85 ng/ml; p < 0.01 respectively). However, there was no significant differences in mean values of serum 25(OH)D levels among studied governorates, subgroups of BMI, WC, marital status, smokers and nonsmoker and subgroups of age. The mean value of serum 25(OH)D was found to be decreased in January, October and November as well as according to diet and sport types. There was significant positive correlation between total 25(OH)D and sun exposed surface area, sun exposure duration and with sun exposure area.

CONCLUSION

Conclusions: The mean (±SD) value of serum total 25(OH)D in Iraqi healthy subjects was 16.29 ng/ml (±8.22) reflecting the actual body status of this vitamin with lower concentration in women than in men. Type and time of sport and diet type were the major vitamin D dependent factors.

Association Between Vitamin D Binding Protein Gene Polymorphism (rs7041), Vitamin D Receptor, and 25-Hydroxyvitamin D Serum Levels With Prostate Cancer in Kurdish Population in West of Iran

Prostate cancer (PCa) pathology has been linked to vitamin D, vitamin D receptors (VDRs), and vitamin D binding proteins (VDBPs). We sought to investigate the association between VDR rs2228570 and rs1544410 as well as VDBP rs7041 polymorphisms and serum 25-hydroxyvitamin D (25(OH)-vitamin D) levels in PCa patients. Blood samples were collected from 111 PCa patients and 150 age-matched healthy volunteers. The VDR rs2228570 T/C, rs1544410 G/A, and VDBP rs7041 T/G genotypes were determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). 25(OH)-vitamin D and PSA (Total and Free) serum levels were measured. The frequencies of VDBP genotypes T/G vs. T/T (56.5% vs. 44.5%, p = 0.01) according to the dominant model T/G + G/G vs. T/T (84.3% vs. 71.5%, p = 0.01) were significantly higher in PCa patients when compared to control group and considerably increased the risk of disease by 2.29, 1.44, and 2.13 folds respectively. Interestingly, the results demonstrated that PCa patients with the dominant model (T/G + G/G vs. T/T) of VDBP had significantly lower serum levels of vitamin D and higher serum levels of total and free PSA in comparison to the controls. Furthermore, when compared to controls, PCa patients with the dominant model T allele (T/G + G/G vs. TT) of VDBP had significantly higher vitamin D, total PSA, and free PSA concentrations. Serum levels of 25(OH)-vitamin D and rs7041 T/G polymorphism of the VDBP gene could be potential risk factors for PCa.

How competing risks affect the epidemiological relationship between vitamin D and prostate cancer incidence? A population-based study

We hypothesized that controversial results regarding the epidemiological relationship between circulating 25-hydroxyvitamin D, 25(OH)D, and risk of prostate cancer (PCA) incidence are partly due to competing risks. To test the hypothesis, we studied associations across 25(OH)D, PCA and death in 2578 middle-aged men belonging to the Kuopio Ischaemic Heart Disease Risk Factor Study. The men were free of cancer at baseline, and the mean (SD) follow-up time was 23.3 (9.1) years. During this period, 296 men had a PCA diagnosis, and 1448 men died without the PCA diagnosis. The absolute risk of developing PCA was highest in the highest 25(OH)D tertile (15%), whereas that of death was highest in the lowest 25(OH)D tertile (67%). A competing risk analysis showed that belonging to the highest 25(OH)D tertile increased the risk of PCA incidence and improved survival with the respective hazard ratios (HR) of 1.35 (95% CI = 1.07-1.70) and 0.79 (95% CI = 0.71-0.89). Adjusting for 10 covariates together with 25(OH)D did not significantly change the results, but the respective adjusted HRs for PCA and death were 1.20 and 0.87. To conclude, the competing risk analysis did not eliminate the direct relationship between 25(OH)D and PCA but rather strengthened it.

Evidence Update on the Relationship between Diet and the Most Common Cancers from the European Prospective Investigation into Cancer and Nutrition (EPIC) Study: A Systematic Review

The European Prospective Investigation into Cancer and Nutrition (EPIC) is a multicentre prospective study conducted in 23 centres in 10 European countries. Here we review the findings from EPIC on the relationship between diet-related exposures and incidence or mortality from the four most frequent cancers in the European population: colorectal, breast, lung, and prostate cancer. We conducted a systematic review following PRISMA guidelines and identified 110 high-quality studies based on the EPIC cohort. Fruit and vegetable consumption had a protective effect against colorectal, breast, and lung cancer, whereas only fruit had a protective effect against prostate cancer. A higher consumption of fish and lower consumption of red and processed meat were related with a lower risk of colorectal cancer; and higher consumption of fatty fish with lower risk of breast cancer. Calcium and yogurt intake were found to protect against colorectal and prostate cancer. Alcohol consumption increased the risk for colorectal and breast cancer. Finally, adherence to the Mediterranean diet emerged as a protective factor for colorectal and breast cancer. The EPIC study results are in agreement with the latest evidence from leading authorities on cancer prevention and help to inform public prevention policies and strategies.

The role of nutritional interventions in prostate cancer: A review

The high prevalence rate in conjunction with the long latency period made prostate cancer (PCa) an attractive and reasonable candidate for preventive measures. So far, several dietary and nutritional interventions have been implemented and studied with the aim of preventing the development or delaying the progression of PCa. Calorie restriction accompanied by weight loss has been shown to be associated with decreased likelihood of aggressive PCa. Supplements have played a major role in nutritional interventions. While genistein and lycopene seemed promising as preventive agents, minerals such as zinc and selenium were shown to be devoid of protective effects. The role of vitamins has been widely studied, with special emphasis on vitamins with antioxidant properties. Data related to Vitamin A and Vitamin C were rather controversial and positive effects were of insignificant magnitude. Vitamin E was associated with a decreased risk of PCa in high-risk groups like smokers. However, when it comes to Vitamin D, the serum levels might affect the risk of PCa. While deficiency of this vitamin was associated with increased risk, high serum levels imposed the risk of aggressive disease. Despite the seemingly promising effects of dietary measures on PCa, no firm recommendation could be made due to the limitations of the studies and evidence. However, the majority of these advices could be followed by the patients with the intent of living a healthy lifestyle.

A Collaborative Analysis of Individual Participant Data from 19 Prospective Studies Assesses Circulating Vitamin D and Prostate Cancer Risk

Previous prospective studies assessing the relationship between circulating concentrations of vitamin D and prostate cancer risk have shown inconclusive results, particularly for risk of aggressive disease. In this study, we examine the association between prediagnostic concentrations of 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH)2D] and the risk of prostate cancer overall and by tumor characteristics. Principal investigators of 19 prospective studies provided individual participant data on circulating 25(OH)D and 1,25(OH)2D for up to 13,462 men with incident prostate cancer and 20,261 control participants. ORs for prostate cancer by study-specific fifths of season-standardized vitamin D concentration were estimated using multivariable-adjusted conditional logistic regression. 25(OH)D concentration was positively associated with risk for total prostate cancer (multivariable-adjusted OR comparing highest vs. lowest study-specific fifth was 1.22; 95% confidence interval, 1.13-1.31; P trend < 0.001). However, this association varied by disease aggressiveness (P heterogeneity = 0.014); higher circulating 25(OH)D was associated with a higher risk of nonaggressive disease (OR per 80 percentile increase = 1.24, 1.13-1.36) but not with aggressive disease (defined as stage 4, metastases, or prostate cancer death, 0.95, 0.78-1.15). 1,25(OH)2D concentration was not associated with risk for prostate cancer overall or by tumor characteristics. The absence of an association of vitamin D with aggressive disease does not support the hypothesis that vitamin D deficiency increases prostate cancer risk. Rather, the association of high circulating 25(OH)D concentration with a higher risk of nonaggressive prostate cancer may be influenced by detection bias. SIGNIFICANCE: This international collaboration comprises the largest prospective study on blood vitamin D and prostate cancer risk and shows no association with aggressive disease but some evidence of a higher risk of nonaggressive disease.

The Epidemiology of Prostate Cancer

Prostate cancer is a major cause of disease and mortality among men, and each year 1.6 million men are diagnosed with and 366,000 men die of prostate cancer. In this review, we discuss the state of evidence for specific genetic, lifestyle, and dietary factors associated with prostate cancer risk. Given the biological heterogeneity of this cancer, we focus on risk factors for advanced or fatal prostate cancer. First, we provide descriptive epidemiology statistics and patterns for prostate cancer incidence and mortality around the world. This includes discussion of the impact of prostate-specific antigen screening on prostate cancer epidemiology. Next, we summarize evidence for selected risk factors for which there is strong or probable evidence of an association: genetics, obesity and weight change, physical activity, smoking, lycopene and tomatoes, fish, vitamin D and calcium, and statins. Finally, we highlight future directions for prostate cancer epidemiology research.

Vitamin D levels in an Australian and New Zealand cohort and the association with pregnancy outcome

BACKGROUND

Pregnant women are at increased susceptibility to vitamin D deficiency. Hence, there is continuing interest in determining how vitamin D influences pregnancy health. We aimed to compare vitamin D status in two distinct populations of pregnant women in Australia and New Zealand and to investigate the relationship between vitamin D status and pregnancy outcome. This included evaluating possible effect measure modifications according to fetal sex.

METHODS

Serum 25-hydroxy vitamin D (25(OH)D) was measured at 15 ± 1 weeks' gestation in 2800 women from Adelaide and Auckland who participated in the multi-centre, prospective cohort SCreening fOr Pregnancy Endpoints (SCOPE) study.

RESULTS

Mean serum 25(OH)D in all women was 68.1 ± 27.1 nmol/L and 28% (n = 772) were considered vitamin D deficient (< 50 nmol/L). Serum 25(OH)D was lower in the women recruited in Adelaide when compared to the women recruited in Auckland and remained lower after adjusting for covariates including maternal body mass index and socioeconomic index (Adelaide: 58.4 ± 50.3 vs. Auckland: 70.2 ± 54.5 nmol/L, P < 0.001). A 53% decreased risk for gestational diabetes mellitus (GDM) was observed with high (> 81 nmol/L) "standardised" vitamin D status when compared to moderate-high (63-81 nmol/L, aRR, 0.47; 95% CI: 0.23, 0.96). Marginal sex-specific differences occurred between vitamin D status and GDM: women carrying a female fetus had a 56% decreased risk for GDM in those with low-moderate levels of standardised vitamin D (44-63 nmol/L) compared to moderate-high levels (aRR: 0.44; 95% CI: 0.20, 0.97), whilst in women carrying a male fetus, a 55% decreased risk of GDM was found with high standardised vitamin D when compared to moderately-high vitamin D, but this was not statistically significant (aRR: 0.45; 95% CI: 0.15, 1.38).

CONCLUSIONS

High serum 25(OH)D at 15 ± 1 weeks' gestation was shown to be protective against the development of GDM. A possible association between fetal sex, vitamin D status and GDM provides further questions and encourages continual research and discussion into the role of vitamin D in pregnancy, particularly in vitamin D replete populations.

Circulating vitamin D concentration and risk of prostate cancer: a dose-response meta-analysis of prospective studies

Background

Though many studies have been performed to elucidate the association between circulating vitamin D and prostate cancer, no conclusive result is available. We carried out a dose-response meta-analysis to quantitatively examine the association of circulating 25-hydroxyvitamin D (25[OH]D) concentration with prostate cancer.

Methods

Only prospective studies examining the associations of circulating 25[OH]D concentration with prostate cancer were eligible for the meta-analysis. A random-effect meta-analysis was done first, to calculate the summary relative risk (RR) and 95% confidence intervals (CIs) comparing the higher concentration with the lower concentration of 25[OH]D. A dose-response meta-analysis using random-effects model was then carried out to evaluate the nonlinearity and calculate the summary RR caused per 10 ng/mL increment.

Results

Nineteen prospective cohort or nested case-control studies were included. Higher 25[OH]D concentration was significantly correlated with elevated risk of prostate cancer (RR =1.15, 95% CI 1.06-1.24). No nonlinear relationship was found between 25[OH]D concentration and risk of prostate cancer (P=0.654). Dose-response meta-analysis showed that the summary RR caused per 10 ng/mL increment in circulating 25[OH]D concentration was 1.04 (95% CI 1.02-1.06). Subgroup analysis also found a modest dose-response relationship. Funnel plot and Egger's test did not detect publication bias.

Conclusion

The findings suggest that highest 25[OH]D concentration is correlated with elevated risk of prostate cancer and a modest dose-response effect exists in this association; however, more studies are needed.

Vitamins, metabolomics, and prostate cancer

PURPOSE

How micronutrients might influence risk of developing adenocarcinoma of the prostate has been the focus of a large body of research (especially regarding vitamins E, A, and D). Metabolomic profiling has the potential to discover molecular species relevant to prostate cancer etiology, early detection, and prevention, and may help elucidate the biologic mechanisms through which vitamins influence prostate cancer risk.

METHODS

Prostate cancer risk data related to vitamins E, A, and D and metabolomic profiling from clinical, cohort, and nested case-control studies, along with randomized controlled trials, are examined and summarized, along with recent metabolomic data of the vitamin phenotypes.

RESULTS

Higher vitamin E serologic status is associated with lower prostate cancer risk, and vitamin E genetic variant data support this. By contrast, controlled vitamin E supplementation trials have had mixed results based on differing designs and dosages. Beta-carotene supplementation (in smokers) and higher circulating retinol and 25-hydroxy-vitamin D concentrations appear related to elevated prostate cancer risk. Our prospective metabolomic profiling of fasting serum collected 1-20 years prior to clinical diagnoses found reduced lipid and energy/TCA cycle metabolites, including inositol-1-phosphate, lysolipids, alpha-ketoglutarate, and citrate, significantly associated with lower risk of aggressive disease.

CONCLUSIONS

Several active leads exist regarding the role of micronutrients and metabolites in prostate cancer carcinogenesis and risk. How vitamins D and A may adversely impact risk, and whether low-dose vitamin E supplementation remains a viable preventive approach, require further study.

Vasectomy and Prostate Cancer Risk in the European Prospective Investigation Into Cancer and Nutrition (EPIC)

Purpose Vasectomy is a commonly used form of male sterilization, and some studies have suggested that it may be associated with an increased risk of prostate cancer, including more aggressive forms of the disease. We investigated the prospective association of vasectomy with prostate cancer in a large European cohort, with a focus on high-grade and advanced-stage tumors, and death due to prostate cancer. Patients and Methods A total of 84,753 men from the European Prospective Investigation into Cancer and Nutrition (EPIC), aged 35 to 79 years, provided information on vasectomy status (15% with vasectomy) at recruitment and were followed for incidence of prostate cancer and death. We estimated the association of vasectomy with prostate cancer risk overall, by tumor subtype, and for death due to prostate cancer, using multivariable-adjusted Cox proportional hazards models. Results During an average follow-up of 15.4 years, 4,377 men were diagnosed with prostate cancer, including 641 who had undergone a vasectomy. Vasectomy was not associated with prostate cancer risk (hazard ratio [HR], 1.05; 95% CI, 0.96 to 1.15), and no evidence for heterogeneity in the association was observed by stage of disease or years since vasectomy. There was some evidence of heterogeneity by tumor grade ( P = .02), with an increased risk for low-intermediate grade (HR, 1.14; 95% CI, 1.01 to 1.29) but not high-grade prostate cancer (HR, 0.83; 95% CI, 0.64 to 1.07). Vasectomy was not associated with death due to prostate cancer (HR, 0.88; 95% CI, 0.68 to 1.12). Conclusion These findings from a large European prospective study show no elevated risk for overall, high-grade or advanced-stage prostate cancer, or death due to prostate cancer in men who have undergone a vasectomy compared with men who have not.

Interactions of the Insulin-Like Growth Factor Axis and Vitamin D in Prostate Cancer Risk in the Prostate Cancer Prevention Trial

Some, but not all, epidemiologic studies report an association between vitamin D and prostate cancer risk. The inconsistent findings might be explained in the context of modification by members of the insulin-like growth factor (IGF) axis. Data and specimens for this nested case-control study (n = 1695 cases and n = 1682 controls) are from the Prostate Cancer Prevention Trial (PCPT). Baseline serum samples were assayed for 25(OH)D, IGF-1, IGF-2, IGFBP-2, IGFBP-3, and the ratio of IGF1:BP3, along with insulin-related markers c-peptide and leptin. The presence of prostate cancer was assessed by prostate biopsy. Multivariate logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CIs) for prostate cancer risk. There were no interactions between serum 25(OH)D and IGF analytes in relation to prostate cancer risk when PCPT treatment arms were combined. In the placebo arm, above median serum 25(OH)D levels were associated with increased risk of prostate cancer among men with higher IGF-2 (OR:1.33, 95% CI: 1.00–1.65), with a significant interaction between 25(OH)D and treatment arm (P_interaction = 0.04). Additionally, there was an interaction between treatment arm and serum IGFBP-3 (P_interaction = 0.03). Higher serum 25(OH)D may increase risk of prostate cancer in the presence of higher circulating IGF-2.

Interactions Between Genome-Wide Significant Genetic Variants and Circulating Concentrations of 25-Hydroxyvitamin D in Relation to Prostate Cancer Risk in the National Cancer Institute BPC3

Genome-wide association studies (GWAS) have identified over 100 single nucleotide polymorphisms (SNPs) associated with prostate cancer. However, information on the mechanistic basis for some associations is limited. Recent research has been directed towards the potential association of vitamin D concentrations and prostate cancer, but little is known about whether the aforementioned genetic associations are modified by vitamin D. We investigated the associations of 46 GWAS-identified SNPs, circulating concentrations of 25-hydroxyvitamin D (25(OH)D), and prostate cancer (3,811 cases, 511 of whom died from the disease, compared with 2,980 controls-from 5 cohort studies that recruited participants over several periods beginning in the 1980s). We used logistic regression models with data from the National Cancer Institute Breast and Prostate Cancer Cohort Consortium (BPC3) to evaluate interactions on the multiplicative and additive scales. After allowing for multiple testing, none of the SNPs examined was significantly associated with 25(OH)D concentration, and the SNP-prostate cancer associations did not differ by these concentrations. A statistically significant interaction was observed for each of 2 SNPs in the 8q24 region (rs620861 and rs16902094), 25(OH)D concentration, and fatal prostate cancer on both multiplicative and additive scales (P ≤ 0.001). We did not find strong evidence that associations between GWAS-identified SNPs and prostate cancer are modified by circulating concentrations of 25(OH)D. The intriguing interactions between rs620861 and rs16902094, 25(OH)D concentration, and fatal prostate cancer warrant replication.

microRNAs and DICER1 are regulated by 1,25-dihydroxyvitamin D in prostate stroma

Vitamin D deficiency increases the risk of lethal prostate adenocarcinomas (PCa) and the majority of older men are deficient. Although PCa arises from the epithelium, the surrounding stroma has hormonal regulatory control over the epithelium and contributes to carcinogenesis. Herein, we describe regulation of microRNAs (miRs) by the active hormone dihydroxyvitamin D (1,25(OH)₂D) in human prostate stroma. 1,25(OH)₂D binds the vitamin D receptor (VDR) transcription factor to regulate gene expression, including miRs, which have emerged as potent regulators of protein expression. 1,25(OH)₂D-regulated miRs were identified by profiling in primary human prostatic stromal cells (PrS) and three miRs, miR-126-3p, miR 154-5p and miR-21-5p were subsequently validated in laser-capture micro-dissected prostate stromal tissue from a vitamin D3 clinical trial (N=45). Regulation of these miRs by 1,25(OH)₂D was VDR-dependent. Network analysis of known and putative mRNA targets of these miRs was enriched with cancer and inflammation pathways, consistent with known roles of stroma and of vitamin D in carcinogenesis. Expression of the miR processing ribonuclease, DICER1, positively correlated with vitamin D metabolite levels in the clinical trial specimens. High epithelial/stromal ratios of DICER1 were significantly associated biochemical recurrence (OR 3.1, p=0.03) in a tissue microarray of 170 matched PCa patients. In summary, these results underscore the role of the prostate stroma in regulating responses to the hormone 1,25(OH)₂D and identified miRs and DICER1 as being regulated in human prostate stroma. Regulation of stromal DICER1 by 1,25(OH)₂D may also have clinical relevance in protection against aggressive PCa.

What Are the Links of Prostate Cancer with Physical Activity and Nutrition? : A Systematic Review Article

BACKGROUND

Prostate cancer (PCa) is the second most common malignancy in men worldwide. The purpose of this study was to provide a brief synthesis the current knowledge for the effects of physical activity (PA) and nutrition on PCa risk.

METHODS

A systematic review of English languages reviews, meta-analysis, and original articles published from 2009 to 2015 extracted from the following websites: MEDLINE, Web of Science, Health Source, Science Direct, and their references.

RESULTS

The review of the literature led to the selection of 12 review or meta-analysis studies and 15 lately published observational studies. Most of studies reported relationship of recreational and occupational PA and vegetables, fruits, vitamins, red/processed meats, and fats consumption with risk of PCa. Decreased risk for PCa associated with exercise was reported in seven of the ten articles on this topic. The inverse association of vegetables and/or fruit intake with PCa risk was reported in eight of 13 papers. The effect of meat/fat intake on PCa was estimated in four articles finding increased risk. There was heterogeneity between studies, and findings are inconsistent.

CONCLUSION

Physical activity does not significantly reduce the risk of PCa; however, vigorous exercise may reduce the risk of aggressive tumor. Besides, there is a lack of definitive evidence supporting the preventive role of diet against PCa. Due to many other benefits of regular moderate-vigorous PA and a diet high in vegetables and fruits and low in red/processed meats and fats, these lifestyle patterns may be recommended.

Plasma 25-hydroxy vitamin D and subsequent prostate cancer risk in a nested Case-Control study in Japan: The JPHC study

BACKGROUND/OBJECTIVES

Although vitamin D has been experimentally reported to inhibit tumorigenesis, cell growth and prostate cancer invasion, epidemiologic data regarding prostate cancer risk are inconsistent, and some studies have suggested positive but nonsignificant associations. Further, the impact of vitamin D on prostate cancer between Western and Japanese populations may differ due to different plasma vitamin D levels.

SUBJECTS/METHODS

We performed a nested case-control study within the Japan Public Health Center-based Prospective (JPHC) Study in 14,203 men (40-69 years) who answered a self-administered questionnaire at baseline (1990-1994) and gave blood samples, and were followed until 2005. We identified 201 prostate cancers which are newly diagnosed during follow-up (mean 12.8 years). We selected two matched controls for each case from the cohort. We used a conditional logistic regression model to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for prostate cancer with respect to levels of 25-hydroxy vitamin D (25(OH)D) in plasma.

RESULTS

We did not observe statistically significant association between 25(OH)D level and total prostate cancer (multivariate OR=1.13 (95%CI=0.66-1.94, P_trend=0.94) for the highest versus lowest tertile) However, 25(OH) levels were slightly positively associated with advanced cancer. The results remained substantially unchanged after stratification by intake of fish or calcium intake.

CONCLUSIONS

25(OH)D level showed no association with overall prostate cancer among Japanese men in this large cohort.

Phase IIa, randomized placebo-controlled trial of single high dose cholecalciferol (vitamin D3) and daily Genistein (G-2535) versus double placebo in men with early stage prostate cancer undergoing prostatectomy

INTRODUCTION AND OBJECTIVES

Prostate cancer (PCa) represents an important target for chemoprevention given its prolonged natural history and high prevalence. Epidemiologic and laboratory data suggest that vitamin D and genistein (soy isoflavone) may decrease PCa progression. The effect of vitamin D on prostate epithelial cell proliferation and differentiation is well documented and genistein may augment this affect through inhibition of the CYP24 enzyme, which is responsible for intracellular vitamin D metabolism. In addition, both genistein and vitamin D inhibit the intraprostatic synthesis of prostaglandin E2, an important mediator of inflammation. The objectives of this prospective multicenter trial were to compare prostate tissue calcitriol levels and down-stream related biomarkers in men with localized prostate cancer randomized to receive cholecalciferol and genistein versus placebo cholecalciferol and placebo genistein during the pre-prostatectomy period.

METHODS

Men undergoing radical prostatectomy were randomly assigned to one of two treatment groups: (1) cholecalciferol (vitamin D₃) 200,000 IU as one dose at study entry plus genistein (G-2535), 600 mg daily or (2) placebo cholecalciferol day 1 and placebo genistein PO daily for 21-28 days prior to radical prostatectomy. Serum and tissue analyses were performed and side-effects recorded.

RESULTS

A total of 15 patients were enrolled, 8 in the placebo arm and 7 in the vitamin D₃ + genistein (VD + G) arm. All patients were compliant and completed the study. No significant differences in side effect profiles were noted. Utilization of the VD + G trended toward increased calcitriol serum concentrations when compared to placebo (0.104 ± 0.2 vs. 0.0013 ± 0.08; p=0.08); however, prostate tissue levels did not increase. Calcidiol levels did not change (p=0.5). Immunohistochemistry for marker analyses using VECTRA automated quantitation revealed a increase in AR expression (p=0.04) and a trend toward increased TUNEL staining (p=0.1) in prostate cancer tissues in men randomized to receive VD + G compared to placebo.

CONCLUSIONS

In this first study testing the combination of a single, large dose of cholecalciferol and daily genistein, the agents were well tolerated. While an increase in AR expression suggesting differentiation was observed, it is difficult to draw firm conclusions regarding the bioactivity of the combination given the sample size.

Do studies reporting 'U'-shaped serum 25-hydroxyvitamin D-health outcome relationships reflect adverse effects?

Several reports describe U-shaped 25-hydroxyvitamin D [25(OH)D] concentration-health outcomes, including musculo-skeletal disorders such as falls and fractures, several cancers, cardiovascular disease (CVD), cognitive function, all-cause mortality rates, birth outcomes, allergic reactions, frailty, and some other disorders. This paper reviews reports of U-shaped outcome associations with vitamin D status for evidence of underlying pathophysiological processes, or of confounding, finding that some U-shaped associations appear to be biologically meaningful, but that many could well reflect confounding by factors such as lifestyle, or hypovitaminosis D-related disease onset being masked by self-supplementation that was begun too late to correct developing health problems but before baseline vitamin D status assessment. However, the various U-shaped associations for allergic reactions may be due to vitamin D modulation of the phenotype of the immune response, shifting the Th1-Th2 balance toward Th2 formation. For prostate cancer, there seems to be little effect of 25(OH)D concentration on incidence; however, there is an inverse correlation between 25(OH)D concentration and mortality rates. Future observational studies, and randomized controlled trial data analyses, should include adjustment for data collected on prior long-term vitamin D supplementation and solar UVB exposure, as well as other potential confounders.

Pre-diagnostic vitamin D concentrations and cancer risks in older individuals: an analysis of cohorts participating in the CHANCES consortium

The associations of circulating 25-hydroxyvitamin D [25(OH)D] concentrations with total and site-specific cancer incidence have been examined in several epidemiological studies with overall inconclusive findings. Very little is known about the association of vitamin D with cancer incidence in older populations. We assessed the association of pre-diagnostic serum 25(OH)D levels with incidence of all cancers combined and incidence of lung, colorectal, breast, prostate and lymphoid malignancies among older adults. Pre-diagnostic 25(OH)D concentrations and cancer incidence were available in total for 15,486 older adults (mean age 63, range 50-84 years) participating in two cohort studies: ESTHER (Germany) and TROMSØ (Norway); and a subset of previously published nested-case control data from a another cohort study: EPIC-Elderly (Greece, Denmark, Netherlands, Spain and Sweden) from the CHANCES consortium on health and aging. Cox proportional hazards or logistic regression were used to derive multivariable adjusted hazard and odds ratios, respectively, and their 95% confidence intervals across 25(OH)D categories. Meta-analyses with random effects models were used to pool study-specific risk estimates. Overall, lower 25(OH)D concentrations were not significantly associated with increased incidence of most of the cancers assessed. However, there was some evidence of increased breast cancer and decreased lymphoma risk with higher 25(OH)D concentrations. Our meta-analyses with individual participant data from three large European population-based cohort studies provide at best limited support for the hypothesis that vitamin D may have a major role in cancer development and prevention among European older adults.

Vitamin D and Immune Response: Implications for Prostate Cancer in African Americans

Prostate cancer (PCa) is the most common cancer among men in the U.S. African American (AA) men have a higher incidence and mortality rate compared to European American (EA) men, but the cause of PCa disparities is still unclear. Epidemiologic studies have shown that vitamin D deficiency is associated with advanced stage and higher tumor grade and mortality, while its association with overall PCa risk is inconsistent. Vitamin D deficiency is also more common in AAs than EAs, and the difference in serum vitamin D levels may help explain the PCa disparities. However, the role of vitamin D in aggressive PCa in AAs is not well explored. Studies demonstrated that the active form of vitamin D, 1,25-dihydroxyvitamin D, has anti-inflammatory effects by mediating immune-related gene expression in prostate tissue. Inflammation also plays an important role in PCa pathogenesis and progression, and expression of immune-related genes in PCa tissues differs significantly between AAs and EAs. Unfortunately, the evidence linking vitamin D and immune response in relation to PCa is still scarce. This relationship should be further explored at a genomic level in AA populations that are at high risk for vitamin D deficiency and fatal PCa.

Vitamin D and Colorectal, Breast, and Prostate Cancers: A Review of the Epidemiological Evidence

Over the past two decades, the question of whether vitamin D has a role in cancer incidence, progression, and mortality has been studied in detail. Colorectal, breast, and prostate cancers have been a particular area of focus; together, these three malignancies account for approximately 35% of cancer cases and 20% of cancer deaths in the United States, and as such are a major public health concern. Herein, we review and synthesize the epidemiological research regarding vitamin D, as measured by the biomarker 25-hydroxycholecalciferol [25(OH)D], and the incidence, progression, and mortality of these cancers. Overall, the results of observational studies of the relationship between 25(OH)D and colorectal cancer have revealed a consistent inverse association for incidence and mortality; while for breast cancer, results have generally demonstrated a relationship between higher 25(OH)D and lower risk for progression and mortality. In contrast, randomized, double-blind clinical trials conducted to date have generally failed to support these findings. For prostate cancer, there is no convincing evidence of an association between 25(OH)D and incidence, and inconsistent data for progression and mortality, though results of one open label clinical trial suggest that supplementation with 4000 IU/d of vitamin D3 may inhibit progression of the disease. Nonetheless, until the results of additional ongoing randomized, double-blind clinical trials are reported, it will be difficult to ascertain if vitamin D itself is related to a reduction in risk for some cancer endpoints, or whether high concentrations of the vitamin D biomarker 25(OH)D may instead serve as a marker for an overall beneficial risk factor profile.

Vitamin D, PTH, and calcium and tumor aggressiveness in prostate cancer: a prospective nested case-control study

PURPOSE

Epidemiological studies suggest that low levels of vitamin D (25OHD) constitute a risk factor for more aggressive prostate cancer. We examined the relationship between pre-diagnostic serum levels of vitamin D, parathyroid hormone (PTH), and calcium and risk of prostate cancer according to tumor aggressiveness.

METHODS

We performed a nested case-control study within the Malmö Diet and Cancer Study on 943 incident prostate cancer cases. Tumor aggressiveness was defined by Gleason score, TNM stage, and serum levels of total prostate-specific antigen. Odds ratios (OR) were calculated for different quartiles of serum levels of 25OHD, PTH, and calcium, and for interactions between them.

RESULTS

We found no significant association when comparing aggressive to non-aggressive disease regarding vitamin D, PTH, or calcium. There was a trend toward an increased risk in low-grade tumors, i.e., Gleason score ≤6, and a significant association regarding Gleason score 7 tumors with OR 1.70 (1.09-2.65) in the highest quartile of vitamin D. Stratifying the analysis yielded several significant findings demonstrating a nonspecific interaction between the metabolites. In men with PTH above median, the risk of aggressive prostate cancer was double in the highest vitamin D quartile, OR 2.01 (1.24-3.25), and for non-aggressive cancer 1.82 (1.25-2.66). There was an inverse effect on risk of prostate cancer in men with PTH above median and vitamin D ≤50 nmol/L, OR 0.25 (0.09-0.71) and calcium ≤2.37 mmol/L, OR 0.53 (0.34-0.82) for aggressive cancer.

CONCLUSIONS

This study showed no significant association when comparing aggressive to non-aggressive disease. There was a possible relationship between vitamin D and low-risk tumors. There were both positive and negative interactions between PTH, calcium, and vitamin D and risk of prostate cancer. These results were similar for low-risk and aggressive cases.

Vitamin D deficiency predicts prostate biopsy outcomes

PURPOSE

The association between vitamin D and prostate biopsy outcomes has not been evaluated. We examine serum vitamin D levels with prostate biopsy results in men with an abnormal prostate-specific antigen and/or digital rectal examination.

EXPERIMENTAL DESIGN

Serum 25-hydroxyvitamin D (25-OH D) was obtained from 667 men, ages 40 to 79 years, prospectively enrolled from Chicago urology clinics undergoing first prostate biopsy. Logistic regression was used to evaluate the associations between 25-OH D status and incident prostate cancer, Gleason score, and tumor stage.

RESULTS

Among European American (EA) men, there was an association of 25-OH D <12 ng/mL with higher Gleason score ≥ 4+4 [OR, 3.66; 95% confidence interval (CI), 1.41-9.50; P = 0.008] and tumor stage [stage ≥ cT2b vs. ≤ cT2a, OR, 2.42 (1.14-5.10); P = 0.008]. In African American (AA) men, we find increased odds of prostate cancer diagnosis on biopsy with 25-OH D < 20 ng/mL [OR, 2.43 (1.20-4.94); P = 0.01]. AA men demonstrated an association between 25-OH D < 12 ng/mL and Gleason ≥ 4+4 [OR, 4.89 (1.59-15.07); P = 0.006]. There was an association with tumor stage ≥ cT2b vs. ≤ cT2a [OR, 4.22 (1.52-11.74); P = 0.003].

CONCLUSIONS

In AA men, vitamin D deficiency was associated with increased odds of prostate cancer diagnosis on biopsy. In both EA and AA men, severe deficiency was positively associated with higher Gleason grade and tumor stage.

Serum 25-hydroxyvitamin D concentrations and risk of prostate cancer: results from the Prostate Cancer Prevention Trial

BACKGROUND

Epidemiologic studies have reported inconsistent associations of vitamin D and prostate cancer risk; however, few have adequately controlled for detection bias related to prostate-specific antigen (PSA) screening, and the results of many studies may be affected by occult prostate cancers among controls.

METHODS

Data for this nested case-control analysis (n = 1,695 cases/1,682 controls) are from the Prostate Cancer Prevention Trial. Baseline serum was analyzed for 25-hydroxyvitamin D [25(OH)D]. The presence or absence of cancer was subsequently determined by prostate biopsy. Polytomous logistic regression models were used to estimate associations of 25(OH)D with risk of total, Gleason 2-6, Gleason 7, and Gleason 8-10 prostate cancer. Results are presented for placebo and finasteride arms separately and combined.

RESULTS

There were no associations of serum 25(OH)D with total prostate cancer risk. For Gleason 2-6 cancers, results were inconsistent across treatment arms with a suggestion of increased risk in the placebo arm only; however, there was no dose-response relationship. For Gleason 8-10 prostate cancers, 25(OH)D concentrations were associated with a linear decrease in risk among combined treatment arms [quartile 4 vs. 1: OR, 0.55; 95% confidence interval (CI), 0.32-0.94; P(trend) = 0.04]. These findings were somewhat stronger among men ≥65 versus 55-64 years at baseline (quartile 4 vs. 1: OR, 0.40; 95% CI, 0.18-0.88 vs. OR, 0.73; 95% CI, 0.35-1.52, respectively; P(interaction) = 0.52).

CONCLUSIONS

Higher serum 25(OH)D may modestly increase risk of Gleason 2-6 disease and more substantially reduce risk of Gleason 8-10 prostate cancer.

IMPACT

Vitamin D may have different effects for different stages of prostate cancers.

Circulating vitamin D, vitamin D-related genetic variation, and risk of fatal prostate cancer in the National Cancer Institute Breast and Prostate Cancer Cohort Consortium

BACKGROUND

Evidence from experimental animal and cell line studies supports a beneficial role for vitamin D in prostate cancer (PCa). Although the results from human studies have been mainly null for overall PCa risk, there may be a benefit for survival. This study assessed the associations of circulating 25-hydroxyvitamin D (25(OH)D) and common variations in key vitamin D-related genes with fatal PCa.

METHODS

In a large cohort consortium, 518 fatal cases and 2986 controls with 25(OH)D data were identified. Genotyping information for 91 single-nucleotide polymorphisms (SNPs) in 7 vitamin D-related genes (vitamin D receptor, group-specific component, cytochrome P450 27A1 [CYP27A1], CYP27B1, CYP24A1, CYP2R1, and retinoid X receptor α) was available for 496 fatal cases and 3577 controls. Unconditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for the associations of 25(OH)D and SNPs with fatal PCa. The study also tested for 25(OH)D-SNP interactions among 264 fatal cases and 1169 controls.

RESULTS

No statistically significant relationship was observed between 25(OH)D and fatal PCa (OR for extreme quartiles, 0.86; 95% CI, 0.65-1.14; P for trend = .22) or the main effects of the SNPs and fatal PCa. There was evidence suggesting that associations of several SNPs, including 5 related to circulating 25(OH)D, with fatal PCa were modified by 25(OH)D. Individually, these associations did not remain significant after multiple testing; however, the P value for the set-based test for CYP2R1 was .002.

CONCLUSIONS

Statistically significant associations were not observed for either 25(OH)D or vitamin D-related SNPs with fatal PCa. The effect modification of 25(OH)D associations by biologically plausible genetic variation may deserve further exploration.

Association between Plasma 25-Hydroxyvitamin D, Ancestry and Aggressive Prostate Cancer among African Americans and European Americans in PCaP

BACKGROUND

African Americans (AAs) have lower circulating 25-hydroxyvitamin D3 [25(OH)D3] concentrations and higher prostate cancer (CaP) aggressiveness than other racial/ethnic groups. The purpose of the current study was to examine the relationship between plasma 25(OH)D3, African ancestry and CaP aggressiveness among AAs and European Americans (EAs).

METHODS

Plasma 25(OH)D3 was measured using LC-MS/MS (Liquid Chromatography Tandem Mass Spectrometry) in 537 AA and 663 EA newly-diagnosed CaP patients from the North Carolina-Louisiana Prostate Cancer Project (PCaP) classified as having either 'high' or 'low' aggressive disease based on clinical stage, Gleason grade and prostate specific antigen at diagnosis. Mean plasma 25(OH)D3 concentrations were compared by proportion of African ancestry. Logistic regression was used to calculate multivariable adjusted odds ratios (OR) and 95% confidence intervals (95%CI) for high aggressive CaP by tertile of plasma 25(OH)D3.

RESULTS

AAs with highest percent African ancestry (>95%) had the lowest mean plasma 25(OH)D3 concentrations. Overall, plasma 25(OH)D3 was associated positively with aggressiveness among AA men, an association that was modified by calcium intake (ORT 3vs.T1: 2.23, 95%CI: 1.26-3.95 among men with low calcium intake, and ORT 3vs.T1: 0.19, 95%CI: 0.05-0.70 among men with high calcium intake). Among EAs, the point estimates of the ORs were <1.0 for the upper tertiles with CIs that included the null.

CONCLUSIONS

Among AAs, plasma 25(OH)D3 was associated positively with CaP aggressiveness among men with low calcium intake and inversely among men with high calcium intake. The clinical significance of circulating concentrations of 25(OH)D3 and interactions with calcium intake in the AA population warrants further study.

Both serum 25-hydroxyvitamin D and calcium levels may increase the risk of incident prostate cancer in Caribbean men of African ancestry

Circulating 25-hydroxyvitamin D [25(OH)D] concentrations have been associated with both higher and lower risk of prostate cancer (PCa), whereas elevated levels of circulating calcium has been related to higher risks. However, there are few studies that account for effects of both calcium and 25(OH)D concentrations on incident PCa in a black population. We examined these relationships in a case–control study of men 40–80 years old with newly diagnosed, histologically confirmed PCa in Jamaica, a tropical country. Mean serum calcium concentrations was higher among cases (2.32 ± 0.19 mmol/L) than controls, (2.27 ± 0.30 mmol/L) (P = 0.023) however, there were no differences in 25(OH)D by cancer status (cases, 33.67 ± 12.71 ng/mL; controls (32.25 ± 12.59 ng/mL). Serum calcium was not correlated with 25(OH)D (partial correlation: r, 0.06; P = 0.287). Multivariable-adjusted models showed a positive linear relationship between PCa and serum calcium (OR, 1.12; CI, 1.00–1.25 per 0.1 nmol/L). Serum 25(OH)D concentration also showed a positive association with PCa (OR, 1.23; CI, 1.01–1.49 per 10 ng/mL). The odds of PCa in men with serum 25(OH)D tertile 2 was OR, 2.18; CI, 1.04–4.43 and OR, 2.47 CI, 1.20–4.90 for tertile 3 (P_trend = 0.013). Dietary intakes of calcium showed no relationship with PCa. Despite the strong relationship between serum calcium and vitamin D the mechanism by which each affects prostate cancer risk in men of African ancestry needs additional investigation.

Plasma vitamin D and prostate cancer risk: results from the Selenium and Vitamin E Cancer Prevention Trial

BACKGROUND

In vitro, animal, and ecological studies suggest that inadequate vitamin D intake could increase prostate cancer risk, but results of biomarker-based longitudinal studies are inconsistent.

METHODS

Data for this case (n = 1,731) and cohort (n = 3,203) analysis are from the Selenium and Vitamin E Cancer Prevention Trial. Cox proportional hazard models were used to test whether baseline plasma vitamin D (25-hydroxy) concentration, adjusted for season of blood collection, was associated with the risk of total and Gleason score 2-6, 7-10, and 8-10 prostate cancer.

RESULTS

There were U-shaped associations of vitamin D with total cancer risk: compared with the first quintile, HRs were 0.83 [95% confidence interval (CI), 0.66-1.03; P = 0.092], 0.74 (95% CI, 0.59-0.92; P = 0.008), 0.86 (95% CI, 0.69-1.07; P = 0.181), and 0.98 (95% CI, 0.78-1.21; P = 0.823), for the second through fifth quintiles, respectively. For Gleason 7-10 cancer, corresponding HRs were 0.63 (95% CI, 0.45-0.90; P = 0.010), 0.66 (95% CI, 0.47-0.92; P = 0.016), 0.79 (95% CI, 0.56-1.10; P = 0.165), and 0.88 (95% CI, 0.63-1.22; P = 0.436). Among African American men (n = 250 cases), higher vitamin D was associated with reduced risk of Gleason 7-10 cancer only: in the a posteriori contrast of quintiles 1-2 versus 3-5, the HR was 0.55 (95% CI, 0.31-0.97; P = 0.037), with no evidence of dose-response or a U-shaped association.

CONCLUSIONS

Both low and high vitamin D concentrations were associated with increased risk of prostate cancer, and more strongly for high-grade disease.

IMPACT

The optimal range of circulating vitamin D for prostate cancer prevention may be narrow. Supplementation of men with adequate levels may be harmful. Cancer Epidemiol Biomarkers Prev; 23(8); 1494-504. ©2014 AACR.

Positive association between circulating 25-hydroxyvitamin D levels and prostate cancer risk: new findings from an updated meta-analysis

PURPOSE

To investigate and clarify the relationship between circulating 25-hydroxyvitamin D level and prostate cancer risk.

METHODS

We conducted the meta-analysis to better evaluate the association. Terms "25-Hydroxyvitamin D"/"vitamin D" and "prostate cancer" were used for literature search.

RESULTS

We identified 21 relevant publications from databases of PubMed and MEDLINE and included 11,941 cases and 13,870 controls in the meta-analysis. Overall studies revealed a significant 17 % elevated risk of prostate cancer for individuals with higher level of 25-hydroxyvitamin D (OR = 1.17, 95 % CI = 1.05-1.30, P  = 0.004), and no publication bias was found in the calculations (P  = 0.629). Subgroup analysis confirmed the association from nested case-control study group, studies from USA group and studies using serum samples group (nested case-control studies: OR = 1.17, 95 % CI = 1.08-1.27, P < 0.001; USA: OR = 1.15, 95 % CI = 1.03-1.29, P = 0.017; serum: OR = 1.20, 95 % CI = 1.01-1.42, P = 0.042); moreover, sensitivity tests also indicated significant results in studies from Europe and studies conducting with plasma samples after exclusion of some influential single study from the analysis, respectively (Europe: OR = 1.21, 95 % CI = 1.04-1.40, P = 0.014; plasma: OR = 1.13, 95 % CI = 1.00-1.27, P = 0.05).

CONCLUSIONS

Our meta-analysis, for the first time, suggested significant positive relationship between high level of 25-hydroxyvitamin D and increased risk of prostate cancer, reminding us that more concern should be taken into account during assessing the effect of 25-hydroxyvitamin D.

Prevention of prostate cancer with vitamins - current perspectives

Cancer prostate is the most common solid malignancy in males of developed countries. With increasing knowledge of the aetiology, pathogenesis and natural history of the disease, influences of dietary factors on prostate cancer development have become more evident. There is ample evidence in the literature of significance of dietary constituents for prostate cancer including vitamins A, D and E. Different vitamins have been found to effect the growth and proliferation of prostate cancer cells as evident in epidemiological, experimental and clinical studies. Various factors play the major role in determining the relationship between these vitamins and prostate cancer in terms of environmental, pharmacological, or genetic aspects. To explore these aspects, the present article reviews the literature on the present status of vitamin use for prevention and management of prostate cancer.

Nutrition, hormones and prostate cancer risk: results from the European prospective investigation into cancer and nutrition

Nutritional factors may influence the risk of developing prostate cancer, but understanding of this topic is poor. This chapter discusses research on this subject, mostly from the European Prospective Investigation into Cancer and Nutrition (EPIC), a cohort which includes 150,000 men recruited in the 1990s in eight European countries. So far the EPIC collaborators have published analyses of the relationship of prostate cancer risk with the intake of a range of foods and nutrients, and with blood-based markers of nutritional factors, on up to nearly 3,000 incident cases of prostate cancer. Most of the results of these analyses have been null, with no clear indication that the risk for prostate cancer is related to intakes of meat, fish, fruit, vegetables, fibre, fat or alcohol or with blood levels of fatty acids, carotenoids, tocopherols, B vitamins, vitamin D, or selenium. There is some evidence from EPIC that risk may be increased in men with a high intake of protein from dairy products, and analyses of hormone levels have shown that risk is higher in men with relatively high blood levels of insulin-like growth factor-I (IGF-I). More research is needed to better describe the relationships of prostate cancer risk with IGF-I and related hormones, and to better understand whether nutritional factors may influence risk through hormones or perhaps by other mechanisms.

The relationship between solar UV exposure, serum vitamin D levels and serum prostate-specific antigen levels, in men from New South Wales, Australia: the CHAMP study

PURPOSE

We aim to determine the relationship between season, personal solar UV exposure, serum 25(OH)D and 1,25(OH)2D and serum prostate-specific antigen (PSA) levels.

METHODS

Questionnaire data and blood samples were collected at baseline from participants of the Concord Health and Ageing in Men Project (n = 1,705), aged 70 and above. They were grouped as men 'free of prostate disease' for those with no record of having prostate cancer, benign prostatic hyperplasia, or prostatitis and with serum PSA levels below 20 ng/mL, and 'with prostate disease' for those with a record of either of these diseases or with serum PSA levels 20 ng/mL or above. Personal solar UV exposure (sUV) was estimated from recalled hours of outdoor exposure and weighted against ambient solar UV radiation. Sera were analysed to determine levels of PSA, 25(OH)D and 1,25(OH)2D, and analysed using multiple regression, adjusting for age, BMI and region of birth.

RESULTS

The association between sUV and serum PSA levels was conditional upon season (p interaction = 0.04). There was no direct association between serum PSA and 25(OH)D in both groups of men. There was a positive association between serum PSA and 1,25(OH)2D in men with prostate disease (mean = 110.6 pmol/L; p heterogeneity = 0.03), but there was no such association in men free of prostate disease (mean = 109.3 pmol/L; p heterogeneity = 0.8).

CONCLUSION

The association between PSA and sUV may only be evident at low solar UV irradiance, and this effect may be independent of serum vitamin D levels.

Genetic variations in VDR associated with prostate cancer risk and progression in a Korean population

Low levels of vitamin D are implicated as a potential risk factor for prostate cancer, and the vitamin D receptor (VDR) gene may be important in the onset and progression of prostate cancer. In this study, sequence variants in the VDR gene were investigated in a Korean study cohort to determine whether they are associated with prostate cancer risk. We evaluated the association between 47 single nucleotide polymorphisms (SNPs) in the VDR gene and prostate cancer risk as well as clinical characteristics (prostate-specific antigen level, clinical stage, pathological stage and Gleason score) in Korean men (272 prostate cancer patients and 173 benign prostatic hyperplasia patient who underwent a prostate biopsy, which was negative for malignancy) using unconditional logistic regression. The statistical analysis suggested that two VDR sequence variants (rs2408876 and rs2239182) had a significant association with prostate cancer risk (odds ratio [OR]. 1.41; p=0.03; OR, 0.73; p=0.05, respectively). Logistic analyses of the VDR polymorphisms with several prostate cancer related factors showed that several SNPs were significant; nine SNPs to PSA level, three to clinical stage, two to pathological stage, and three SNPs to the Gleason score. The results suggest that some VDR gene polymorphisms in Korean men might not only be associated with prostate cancer risk but also significantly related to prostate cancer-related risk factors such as PSA level, tumor stage, and Gleason score. However, current limitation for small cohort with not-healthy control group might have false positive effects; therefore it should be overcome via further large-scale validating studies.

Serum calcium concentration and prostate cancer risk: a multicenter study

This study sought to further evaluate the possible effects of serum calcium level on prostate cancer (PC) risk, with considering the age, body mass index (BMI), and sex steroid hormones. Using data from a prospective multicenter study, serum calcium concentration, as well as thorough demographic and medical characteristics, were determined in 194 cases with newly diagnosed, clinicopathologically confirmed PC and 317 controls, without any malignant disease, admitted to the same network of hospitals. Serum total and ionized calcium levels were categorized into tertiles. Multivariate logistic regression model was used to estimate odds ratios (OR) and corresponding 95% confidence intervals (CI) after adjustment for major potential confounders, including age, BMI, smoking, alcohol, education, occupation, marital status, family history of PC, and sex hormones level. The mean serum calcium level (±SD) in case and control groups was 9.22 (±0.46) mg/dl and 9.48 (±0.51) mg/dl, respectively (P < 0.001). After adjustment for mentioned confounders, a significant trend of decreasing risk was found for serum total calcium concentration (OR = 0.27, 95% CI = 0.12-0.59, comparing the highest with the lowest tertile) and ionized calcium (OR = 0.25, 95% CI = 0.10-0.58). An increase of 1 mg/dl in serum calcium level was associated with a significant decrease in PC risk (OR = 0.52; 95% CI = 0.34-0.76). Our findings reveal the inverse association between serum total and ionized concentrations and PC risk, which supports the hypothesis that calcium may protect against PC. Furthermore, no evidence was found regarding age, BMI, and sex steroid hormones to modify the association between serum calcium and PC risk.

Ultraviolet index and racial differences in prostate cancer incidence and mortality

BACKGROUND

Studies suggest that low levels of vitamin D may be associated with prostate cancer, and darker skin reduces the body's ability to generate vitamin D from sunshine. The impact of sunshine on racial disparities in prostate cancer incidence and mortality is unknown.

METHODS

Using the Surveillance, Epidemiology, and End Results program database, the authors calculated age-adjusted prostate cancer incidence rates among black and white men aged ≥ 45 years by race and county between 2000 and 2009 (N = 906,381 men). Similarly, county-level prostate cancer mortality rates were calculated from the National Vital Statistics System (N = 288,874). These data were linked with the average monthly solar ultraviolet (UV) radiation index by county and data regarding health, wellness, and demographics. Multivariable regression analysis was used to assess whether increases in the UV index (in deciles) moderated the association between black race and the incidence and mortality of prostate cancer.

RESULTS

Compared with counties in the lowest UV index decile, prostate cancer incidence rates for white and black men were lower in counties with a higher UV index (all Ps ≤ 0.051). Incidence rates were higher for black men versus white men, but the difference by race was less for counties in the fourth to fifth UV index deciles versus those in the first decile (Ps  ≤  0.02). Mortality rates also were found to decrease with increasing UV index for white men (Ps  ≤  0.003), but increase for black men, and an unexplained increase in racial differences in mortality rates was observed with an increasing UV index.

CONCLUSIONS

Racial disparities in the incidence of prostate cancer were larger in some areas with less sunshine. Additional research should confirm the findings of the current study and assess whether optimizing vitamin D levels among black men can reduce disparities.

Antineoplastic effects of 1,25(OH)2D3 and its analogs in breast, prostate and colorectal cancer

The active form of vitamin D3, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), is mostly known for its importance in the maintenance of calcium and phosphate homeostasis. However, next to its classical effects on bone, kidney and intestine, 1,25(OH)2D3 also exerts antineoplastic effects on various types of cancer. The use of 1,25(OH)2D3 itself as treatment against neoplasia is hampered by its calcemic side effects. Therefore, 1,25(OH)2D3-derived analogs were developed that are characterized by lower calcemic side effects and stronger antineoplastic effects. This review mainly focuses on the role of 1,25(OH)2D3 in breast, prostate and colorectal cancer (CRC) and the underlying signaling pathways. 1,25(OH)2D3 and its analogs inhibit proliferation, angiogenesis, migration/invasion and induce differentiation and apoptosis in malignant cell lines. Moreover, prostaglandin synthesis and Wnt/b-catenin signaling are also influenced by 1,25(OH)2D3 and its analogs. Human studies indicate an inverse association between serum 25(OH)D3 values and the incidence of certain cancer types. Given the literature, it appears that the epidemiological link between vitamin D3 and cancer is the strongest for CRC, however more intervention studies and randomized placebo-controlled trials are needed to unravel the beneficial dose of 1,25(OH)2D3 and its analogs to induce antineoplastic effects.

Is prevention of cancer by sun exposure more than just the effect of vitamin D? A systematic review of epidemiological studies

The number of studies reporting on the association between sunlight exposure, vitamin D and cancer risk is steadily increasing. We reviewed all published case-control and cohort studies concerning colorectal-, prostate-, breast cancer, non-Hodgkin's lymphoma (NHL) and both sunlight and vitamin D to update our previous review and to verify if the epidemiological evidence is in line with the hypothesis that the possible preventive effect of sunlight on cancer might be mediated not only by vitamin D but also by other pathways. We found that almost all epidemiological studies suggest that chronic (not intermittent) sun exposure is associated with a reduced risk of colorectal-, breast-, prostate cancer and NHL. In colorectal- and to a lesser degree in breast cancer vitamin D levels were found to be inversely associated with cancer risk. In prostate cancer and NHL, however, no associations were found. These findings are discussed and it is concluded that the evidence that sunlight is a protective factor for colorectal-, prostate-, breast cancer and non-Hodgkin's lymphoma is still accumulating. The same conclusion can be drawn concerning high vitamin D levels and the risk of colorectal cancer and possibly breast cancer. Particularly in prostate cancer and NHL other sunlight potentiated and vitamin D independent pathways, such as modulation of the immune system and the circadian rhythm, and the degradation of folic acid might play a role in reduced cancer risk as well.

Genetic variation in the lactase gene, dairy product intake and risk for prostate cancer in the European prospective investigation into cancer and nutrition

High dairy protein intake has been found to be associated with increased prostate cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC). To further examine this possible relationship, we investigated the hypothesis that a genetic polymorphism in the lactase (LCT) gene might be associated with elevated dairy product intake and increased prostate cancer risk in a case–control study nested in EPIC. The C/T-13910 lactase variant (rs4988235) was genotyped in 630 men with prostate cancer and 873 matched control participants. Dairy product consumption was assessed by diet questionnaire. Odds ratios (ORs) for prostate cancer in relation to lactase genotype were estimated by conditional logistic regression. Lactase genotype frequency varied significantly between countries, with frequencies of the T (lactase persistence) allele ranging from 7% in Greece to 79% in Denmark. Intake of milk and total dairy products varied significantly by lactase genotype after adjustment for recruitment center; adjusted mean intakes of milk were 44.4, 69.8 and 82.3 g/day among men with CC, CT and TT genotypes, respectively. The lactase variant was not significantly associated with prostate cancer risk, both in our data (adjusted OR for TT vs. CC homozygotes: 1.10, 95% CI: 0.76–1.59) and in a meta-analysis of all the published data (combined OR for T allele carriers vs. CC homozygotes: 1.12, 0.96–1.32). These findings show that while variation in the lactase gene is associated with milk intake in men, the lactase polymorphism does not have a large effect on prostate cancer risk.

What's new?

High dairy protein intake has previously been found to be associated with increased prostate cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC). The current study was nested in EPIC, and results from this first Europe-wide study suggest that while the C/T13910 lactase polymorphism is associated with milk intake, the variant has no large effect on prostate cancer risk. The data illustrate the challenges of applying mendelian randomisation to explore the relationship between dairy product consumption and cancer risk. Very large studies with both genetic and dietary data are thus needed for investigations using genetic proxies of nutritional exposures.

Vitamin D and Major Chronic Illness

OBJECTIVE

To review the current literature regarding vitamin D insufficiency and supplementation in major illnesses.

DESIGN AND METHODS

We reviewed Pubmed-indexed, English language manuscripts from January, 2003 to June, 2012 using search terms related to vitamin D, all-cause mortality, cardiovascular disease, pulmonary disease, diabetes mellitus, and cancer.

OUTCOME MEASURES

Incidence of disease, risk ratios associated with 25-hydroxyvitamin D [25(OH)D] levels, and/or vitamin D supplementation schedules were documented.

RESULTS

Although 25(OH)D levels ≥20 ng/mL were often associated with improved health outcomes, evidence suggests that 25(OH)D levels ≥30 ng/mL may confer additional health benefits.

CONCLUSIONS

Based on the available evidence, vitamin D supplementation to restore 25(OH)D levels within a range of 30-50 ng/mL is reasonable in order to optimize potential benefits and minimize potential risks. This, of course, should be considered in the context of individual patient needs and co-morbidities.

[Osteoporosis in men receiving androgen deprivation therapy for non-metastatic prostate cancer]

Osteoporosis is defined as a continuous loss of bone mineral density accompanied by an increased fracture risk in females and males. A fall of estrogen concentrations at the menopause and the consecutive rapid bone loss are an established pathogenic mechanism in female osteoporosis. Males do not have a menopause equivalent during which significant amounts of bone are lost. Several diseases, therapeutic strategies and nutritional deficiencies may also result in bone loss and reduced bone mineral density. Prostate cancer is the most common visceral malignancy in men. Suppression of endogenous androgen production as a therapeutic tool is commonly used in patients with non-metastatic prostate cancer and is associated with significant bone loss and an increased fracture risk. Androgen deprivation therapy is prescribed both for men with locally advanced or high-risk non-metastatic prostate cancer. Osteoclast inhibition with any of several bisphosphonates improves bone mineral density and reduces fracture risk. Denosumab (a monoclonal antibody against RANK ligand) and toremifene (a selective estrogen receptor modulator) recently have been shown to be effective to reduce vertebral fractures in patients with non-metastatic prostate cancer receiving androgen-deprivation therapy. This overview focuses on cancer-treatment-induced bone loss in patients with non-metastatic prostate cancer.

Vitamin D and cancer

Vitamin D system is a complex pathway that includes precursors, active metabolites, enzymes, and receptors. This complex system actives several molecular pathways and mediates a multitude of functions. In addition to the classical role in calcium and bone homeostasis, vitamin D plays "non-calcemic" effects in host defense, inflammation, immunity, and cancer processes as recognized in vitro and in vivo studies. The aim of this review is to highlight the relationship between vitamin D and cancer, summarizing several mechanisms proposed to explain the potential protective effect of vitamin D against the development and progression of cancer. Vitamin D acts like a transcription factor that influences central mechanisms of tumorigenesis: growth, cell differentiation, and apoptosis. In addition to cellular and molecular studies, epidemiological surveys have shown that sunlight exposure and consequent increased circulating levels of vitamin D are associated with reduced reduced occurrence and a reduced mortality in different histological types of cancer. Another recent field of interest concerns polymorphisms of vitamin D receptor (VDR); in this context, preliminary data suggest that VDR polymorphisms more frequently associated with tumorigenesis are Fok1, Bsm1, Taq1, Apa1, EcoRV, Cdx2; although further studies are needed to clarify their role in the cancer. In this review, the relationship between vitamin D and cancer is discussed.

Vitamin D-related genetic variation, plasma vitamin D, and risk of lethal prostate cancer: a prospective nested case-control study

BACKGROUND

The association of vitamin D status with prostate cancer is controversial; no association has been observed for overall incidence, but there is a potential link with lethal disease.

METHODS

We assessed prediagnostic 25-hydroxyvitamin D [25(OH)D] levels in plasma, variation in vitamin D-related genes, and risk of lethal prostate cancer using a prospective case-control study nested within the Health Professionals Follow-up Study. We included 1260 men who were diagnosed with prostate cancer after providing a blood sample in 1993-1995 and 1331 control subjects. Men with prostate cancer were followed through March 2011 for lethal outcomes (n = 114). We selected 97 single-nucleotide polymorphisms (SNPs) in genomic regions with high linkage disequilibrium (tagSNPs) to represent common genetic variation among seven vitamin D-related genes (CYP27A1, CYP2R1, CYP27B1, GC, CYP24A1, RXRA, and VDR). We used a logistic kernel machine test to assess whether multimarker SNP sets in seven vitamin D pathway-related genes were collectively associated with prostate cancer. Tests for statistical significance were two-sided.

RESULTS

Higher 25(OH)D levels were associated with a 57% reduction in the risk of lethal prostate cancer (highest vs lowest quartile: odds ratio = 0.43, 95% confidence interval = 0.24 to 0.76). This finding did not vary by time from blood collection to diagnosis. We found no statistically significant association of plasma 25(OH)D levels with overall prostate cancer. Pathway analyses found that the set of SNPs that included all seven genes (P = .008) as well as sets of SNPs that included VDR (P = .01) and CYP27A1 (P = .02) were associated with risk of lethal prostate cancer.

CONCLUSION

In this prospective study, plasma 25(OH)D levels and common variation among several vitamin D-related genes were associated with lethal prostate cancer risk, suggesting that vitamin D is relevant for lethal prostate cancer.

[Epidemiology of prostate cancer]

Since a number of years, prostate cancer has been the most frequent cancer site among men in Germany and has replaced lung cancer as the leading position. Among the most frequent cancer sites, it is the one with the lowest available knowledge about etiology. Smoking and alcohol apparently do not play a role. Regarding food intake, indications exist for a protective association to tomatoes or lycopene consumption and a protective association was also seen with high physical activity, while risk seems to be elevated in obese men. Associations to hormonal factors have been observed and are under consideration. Trials with potential chemopreventive agents have been unsuccessful so far. For early detection, digital rectal examination has been part of the German statutory early detection program" from the very beginning in 1971 and the test for prostate specific antigen (PSA) is being used in the framework of the so-called individual health services, both without scientific evidence of effectiveness. The available data show that the progression of prostate cancer to the leading male cancer site was chiefly driven by the unstructured introduction of the PSA test as a screening tool. Cynically addressed, the figures indicate that the most efficient known preventive intervention was not to attend screening. This delicate situation should, however, not discourage from further examinations of prostate cancer screening. Recent results including the European randomized prostate cancer screening study (ERSPC) indicated that intelligently structured screening, possibly even using the PSA test, might be effective. Before routine application the novel approaches also have to be scrutinized in a research setting.

Prostate cancer incidence in Australia correlates inversely with solar radiation

What's known on the subject? and What does the study add? Increased sun exposure and blood levels of vitamin D have been postulated to be protective against prostate cancer. This is controversial. We investigated the relationship between prostate cancer incidence and solar radiation in non-urban Australia, and found a lower incidence in regions receiving more sunlight. In landmark ecological studies, prostate cancer mortality rates have been shown to be inversely related to ultraviolet radiation exposure. Investigators have hypothesised that ultraviolet radiation acts by increasing production of vitamin D, which inhibits prostate cancer cells in vitro. However, analyses of serum levels of vitamin D in men with prostate cancer have failed to support this hypothesis. This study has found an inverse correlation between solar radiation and prostate cancer incidence in Australia. Our population (previously unstudied) represents the third group to exhibit this correlation. Significantly, the demographics and climate of Australia differ markedly from those of previous studies conducted on men in the United Kingdom and the United States.

OBJECTIVE

• To ascertain if prostate cancer incidence rates correlate with solar radiation among non-urban populations of men in Australia.

PATIENTS AND METHODS

• Local government areas from each state and territory were selected using explicit criteria. Urban areas were excluded from analysis. • For each local government area, prostate cancer incidence rates and averaged long-term solar radiation were obtained. • The strength of the association between prostate cancer incidence and solar radiation was determined.

RESULTS

• Among 70 local government areas of Australia, age-standardized prostate cancer incidence rates for the period 1998-2007 correlated inversely with daily solar radiation averaged over the last two decades.

CONCLUSION

•  There exists an association between less solar radiation and higher prostate cancer incidence in Australia.

Serum 25-hydroxy vitamin D and prostate cancer risk in a large nested case-control study

BACKGROUND

Vitamin D compounds inhibit prostate tumorigenesis experimentally, but epidemiologic data are inconsistent with respect to prostate cancer risk, with some studies suggesting nonsignificant positive associations.

METHODS

The 25-hydroxy vitamin D [25(OH)D]-prostate cancer relation was examined in a nested case-control study within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study of 50- to 69-year-old Finnish men. We matched 1,000 controls to 1,000 cases diagnosed during up to 20 years of follow-up on the basis of age (±1 year) and fasting blood collection date (±30 days). Conditional multivariate logistic regression models estimated ORs and 95% CIs. All statistical significance testing was 2-sided.

RESULTS

Cases had nonsignificantly 3% higher serum 25(OH)D levels (P = 0.19). ORs (95% CIs) for increasing season-specific quintiles of 25(OH)D concentrations were 1.00 (reference), 1.29 (0.95-1.74), 1.34 (1.00-1.80), 1.26 (0.93-1.72), and 1.56 (1.15-2.12), with P(trend) = 0.01. Analyses based on prespecified clinical categories and season-adjusted values yielded similar results. These findings seemed stronger for aggressive disease [OR (95% CI) for fifth quintile of serum 25(OH)D [1.70 (1.05-2.76), P(trend) = 0.02], among men with greater physical activity [1.85 (1.26-2.72), P(trend) = 0.002], higher concentrations of serum total cholesterol [2.09 (1.36-3.21), P(trend) = 0.003] or α-tocopherol [2.00 (1.30-3.07), P(trend) = 0.01] and higher intakes of total calcium [1.82 (1.20-2.76), P(trend) = 0.01] or vitamin D [1.69 (1.04-2.75), P(trend) = 0.08], or among those who had received the trial α-tocopherol supplements [1.74 (1.15-2.64), P(trend) = 0.006].

CONCLUSION

Our findings indicate that men with higher vitamin D blood levels are at increased risk of developing prostate cancer.

IMPACT

Greater caution is warranted with respect to recommendations for high-dose vitamin D supplementation and higher population target blood levels.

Effect of interval between serum draw and follow-up period on relative risk of cancer incidence with respect to 25-hydroxyvitamin D level: Implications for meta-analyses and setting vitamin D guidelines

Ecological studies have reported strong inverse correlations between indices of solar ultraviolet-B (UVB) doses and incidence and/or mortality rates for many types of cancer. Case-control studies (CCS) generally find inverse correlations between serum 25-hydroxyvitamin D [25(OH)D] concentration measured at time of diagnosis for cancer incidence, whereas nested case-control studies (NCCS), which involve a several-year follow-up time after serum sampling, generally do not. This paper examines the relation between follow-up interval and relative risk (RR) for breast, colorectal, and prostate cancer. I plot the RR versus serum 25(OH)D data as a function of follow-up time from the literature for each type of cancer. For breast cancer, RRs were significantly reduced only for follow-up periods less than 3 years. For colorectal cancer, RRs were generally significantly reduced for follow-up periods up to 12 years. For prostate cancer, RRs were not statistically significant from 4 years to 28 years. This study included no CCS. Follow-up periods after serum sampling should not be too long for breast cancer because once a tumor reaches a diameter of 1-3 mm, it requires angiogenesis to continue growing, and vitamin D reduces angiogenesis around tumors. Breast cancer diagnoses are more common in spring and fall than in summer or winter, indicating that they can grow rapidly if circulating 25(OH)D drops in the fall or melatonin levels drop in spring. Serum sampling should be conducted during the study, perhaps every 2 years, to overcome the problem of change of 25(OH)D concentration during cohort studies.

Prostate cancer and vitamin D: what does the evidence really suggest?

The optimal approach to vitamin D supplementation for the average healthy person is debatable. In patients with cancer, the role of vitamin D supplementation, possibly in treatment, is even less clear. Vitamin D is shown to play a role in prostate cancer biology; however, the clinical data have not consistently demonstrated a link. Additional studies are needed to determine if higher doses of vitamin D supplements could benefit selected populations (ie, the elderly or patients with cancer) even if they may not be beneficial for the general population.

Vitamin d, sunlight and prostate cancer risk

Prostate cancer is the second common cancer in men worldwide. The prevention of prostate cancer remains a challenge to researchers and clinicians. Here, we review the relationship of vitamin D and sunlight to prostate cancer risk. Ultraviolet radiation of the sunlight is the main stimulator for vitamin D production in humans. Vitamin D's antiprostate cancer activities may be involved in the actions through the pathways mediated by vitamin D metabolites, vitamin D metabolizing enzymes, vitamin D receptor (VDR), and VDR-regulated genes. Although laboratory studies including the use of animal models have shown that vitamin D has antiprostate cancer properties, whether it can effectively prevent the development and/or progression of prostate cancer in humans remains to be inconclusive and an intensively studied subject. This review will provide up-to-date information regarding the recent outcomes of laboratory and epidemiology studies on the effects of vitamin D on prostate cancer prevention.

Melanoma and vitamin D

Vitamin D is a fat-soluble steroid hormone, which is essential to health and for which epidemiological studies suggest a role in autoimmune disease, infections, cardiovascular disease and cancer. It is ingested in foods such as oily fish and supplements, so that average levels vary between countries, but most individuals worldwide make most of their vitamin D as a result of the effects of sun exposure on the skin. Many studies in different populations around the world have in recent years shown that sub-optimal levels of vitamin D (<70 nmol/L) are common. A series of epidemiological studies have suggested that low vitamin D levels increase the risk of cancers, particularly of the breast and gastrointestinal tracts, so that there has been much interest in understanding the effects of vitamin D on cancer cells. Vitamin D binds to the vitamin D receptor (VDR) resulting in transcription of a number of genes playing a role in inhibition of MAPK signalling, induction of apoptosis and cell-cycle inhibition, and therefore vitamin D has anti-proliferative and pro-apoptotic effects in cells of many lineages. It also has suppressive effects on adaptive immunity and is reported to promote innate immunity. Here we review data on vitamin D and melanoma. There are in vitro data, which suggest that vitamin D has the same anti-proliferative effects on melanoma cells as have been demonstrated in other cells. We have reported data to suggest that vitamin D levels at diagnosis have a role in determining outcome for melanoma patients. There is a curious relationship between melanoma risk and sun exposure where sunburn is causal but occupational sun exposure is not (at least in temperate climes). Seeking to understand this, we discuss data, which suggest (but by no means prove) that vitamin D might also have a role in susceptibility to melanoma. In conclusion, much remains unknown about vitamin D in general and certainly about vitamin D and melanoma. However, the effects of avoidance of suboptimal vitamin D levels on cancer cell proliferation are likely to be beneficial to the melanoma patient. The possible results of high vitamin D levels on the immune system remain unclear however and a source of some concern, but the data support the view that serum levels in the range 70-100 nmol/L might be a reasonable target for melanoma patients as much as for other members of the population.