Vitamin D receptor (VDR) gene polymorphisms and haplotypes, interactions with plasma 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D, and prostate cancer risk

Vitamin D Receptor (VDR) Allelic Variants Correlating with Response to Vitamin D3 Supplementation in Breast Cancer Survivors

We investigated how vitamin D receptor (VDR) allelic variants affect breast cancer survivors' responses to vitamin D3 supplementation to increase circulating 25-hydroxy vitamin D (25(OH)D) levels. Two hundred and fourteen patients who were diagnosed with breast cancer at least 6 mo, prior to the study and had completed all treatment regimens were assigned to consume 4000 IU of vitamin D3 daily for 12 weeks. Linear and multinomial logistic regression analyses were used to analyze the association of VDR single nucleotide polymorphism (SNPs) with changes in circulating 25(OH)D. The TaqI and BsmI VDR sequence variants modified the effect of vitamin D3 treatment on the plasma 25(OH)D changes (P value = 0.008 for TaqI and P value = 0.0005 for BsmI). Patients with the bb [Q4 vs. Q1 odds ratio(OR) 8.04, 95% confidence interval (CI) 1.55-41.57] and tt [Q4 vs. Q1 OR 4.64 95%CI 1.02-21.02] genotype of BsmI and TaqI had larger increases in plasma 25(OH)D levels compared to those with BB and TT genotype respectively after adjustment for potential confounders. Haplotype analyses suggested the existence of specific combination of alleles that might be associated with circulating 25(OH)D changes. VDR allelic variants modulate vitamin D3 supplementation to increase plasma 25(OH) levels in breast cancer survivors.

The Association Between the Genetic VDR SNP c.907+75C>T and Prostate Cancer Risk Is Modified by Tanning Potential

BACKGROUND

Prostate cancer (PCa) is a multifactorial disease involving complex interactions between genetic and physiological/environmental factors. Vitamin D receptor (VDR) plays a role in numerous cellular pathways and it has been suggested that VDR genetic variants influence individual susceptibility to PCa.

MATERIALS AND METHODS

Logistic regression analysis was used to assess the association of six VDR single nucleotide polymorphisms (SNPs) and factors such as tanning potential and UV sunlight exposure with PCa risk.

RESULTS

Marginal significant interactions were found, with a 2-fold increase risk of PCa between SNP 1 (c.278-69G>A) and sunlight UV exposure [odds ratio (OR)=2.02, 95% confidence intervaI (CI)=1.036-4.36; p=0.05]; and a 4-fold increase risk of PCa between SNP 4 (c.907+75C>T) and tanning potential (OR=4.40, 95% CI=0.89-29.12; p=0.0591). In contrast, SNP 5 (rs731236, TaqI) and tanning potential interaction had a protective effect by reducing the risk of PCa by 55% (β=-0.804; OR=0.448, 95% CI=0.197-9.42; p=0.0427). SNPs 2 (rs61614328) and 6 (rs533037428) did not show any association with PCa even in the presence of UV sunlight exposure.

CONCLUSION

The protective effect of SNP 4 from PCa is lost and modified by tanning potential in African Americans. This finding needs to be verified by larger studies in different ethnic populations.

Vitamin D Receptor Polymorphisms and Cancer

Increasing scientific evidence supports the link between vitamin D and cancer risk. The active metabolite 1,25(OH)2D exerts its activity by binding to the vitamin D receptor (VDR), an intracellular receptor that mediates transcriptional activation and repression of target genes. The binding of 1,25(OH)2D to VDR is able to regulate hundreds of different genes. VDR is active in virtually all tissues including the colon, breast, lung, ovary, bone, kidney, parathyroid gland, pancreatic b-cells, monocytes, T lymphocytes, melanocytes, keratinocytes, and also cancer cells.The relevance of VDR gene restriction fragment length polymorphisms for various types of cancer has been investigated by a great number of studies.We have carried out a systematic review of the literature to analyze the relevance of more VDR polymorphisms (Fok1, Bsm1, Taq1, Apa1, and Cdx2) for individual malignancies considering ethnicity as a key factor for heterogeneity.Up to December 2018, we identified 176 independent studies with data to assess the risk of breast, prostate, colorectal, skin (melanoma and non-melanoma skin cancer), lung, ovarian, kidney, bladder, gallbladder, esophageal, thyroid, head and neck, liver and pancreatic cancer, oral squamous cell carcinoma, non-Hodgkin lymphoma, multiple myeloma and sarcoma.Significant associations with VDR polymorphisms have been reported for prostate (Fok1, Bsm1, Taq1, Apa1, Cdx2), breast (Fok1, Bsm1, Taq1, Apa1, CdX2), colorectal (Fok1, Bsm1, Taq1, Apa1), and skin cancer (Fok1, Bsm1, Taq1). Very few studies reported risk estimates for the other cancer sites.Conflicting data have been reported for most malignancies, and at present, it is still not possible to make any definitive statements about the importance of the VDR genotype for cancer risk. It seems probable that other factors such as ethnicity, phenotype, 25(OH)D plasma levels, and UV radiation exposure play a role as confounding factors and introduce heterogeneity.To conclude, there is some indication that VDR polymorphisms may modulate the risk of some cancer sites and in future studies VDR genetic variation should be integrated also with assessment of vitamin D status and stratified by ethnicity.

The Association of a Novel Identified VDR SNP With Prostate Cancer in African American Men

BACKGROUND/AIM

Vitamin D receptor (VDR) is present in numerous cellular pathways and it has been suggested that VDR genetic variants influence individual susceptibility to prostate cancer. Also, analyses of single nucleotide polymorphisms (SNPs) in VDR revealed ethnicity-associated polymorphisms. The aim of this study was to identify VDR SNPs in African American men with and without prostate cancer.

MATERIALS AND METHODS

The entire VDR gene was screened for germline mutations in a case-control study by denaturing high performance liquid chromatography and DNA sequencing. Logistic regression was used to estimate the association of SNPs, age, family history, and Gleason score with prostate cancer risk.

RESULTS

Six SNPs in the non-coding regions, and one SNP in the coding region, were detected. SNP 1 (c.278-69G>A) and SNP 4 (c.907+75C>T) have not been previously reported. SNP 4 had a significant protective effect (β=-0.6, p<0.05); whereas, SNP 7 (rs7975232) showed an increase association with prostate cancer risk and high Gleason score (β=0.32, p<0.05). SNP 4, SNP 7 and age were better predictors of prostate cancer risk than family history with a high degree of sensitivity (74.7%) and specificity (92.4%).

CONCLUSION

SNP 4 and SNP 7 could be promising markers for prediction of reduced or increased prostate cancer risk, respectively.

Effect of Vitamin D Supplementation in Prostate Cancer: A Systematic Review of Randomized Control Trials

Vitamin D is important in many cellular functions including cell cycling and proliferation, differentiation, and apoptosis. Via the induction of cell cycle arrest and/or apoptosis, vitamin D inhibits normal prostatic epithelial cells growth. Review the evidence of the effect of vitamin D supplementation on prostate cancer (PC) biomarkers and patient survival and assess optimal dosage, formulation and duration. Pubmed, Medline and Ebsco Host databases were systematically searched for relevant literature. 8 Randomized Controlled Trials were included in this review. All studies, besides one, were of high methodological quality. 4 studies used calcitriol (0,5-45 μg/weekly), 2 studies have used vitamin D3 (150-1000 μg/daily) and 2 other studies have used 1α-hydroxy Vitamin D2 (10 μg/ daily or weekly). Duration of supplementation varied between 28 days up to 18.3 months. Two studies had positive effects on prostate specific antigen (PSA) (p < .05), 1 study had a significant positive effect on median survival (p < .05) and 1 study showed a significant reduction of vitamin D receptor (VDR) expression (p < .05). The remaining studies showed negative or no effect on PC characteristics, clinical outcomes and/or survival. Current evidence suggests that vitamin D supplementation in conjunction with standard of care (e.g. chemotherapy, radiation therapy) may confer clinical benefits such as a decrease in serum PSA levels and VDR expression but further research is required to ascertain these results. Calcitriol supplementation in doses ranging from 250-1000 mg for 3-8 weeks or a lower dose of 45 mg for 18.3 months, appear most beneficial regarding outcomes of PC progression and survival.

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.

Lack of association between the risk of prostate cancer and vitamin D receptor Bsm I polymorphism: a meta-analysis of 27 published studies

BACKGROUND

The association between vitamin D receptor gene Bsm I (rs1544410) polymorphism and prostate cancer (PCa) risk has been investigated by numerous previous studies, which yielded inconsistent results. We conducted this meta-analysis to derive a relatively precise description of this association.

METHODS

All studies published up to December 2017 were identified via a systematic search of PubMed, Embase, and China National Knowledge Infrastructure databases. Pooled odds ratios (ORs) with their 95% confidence intervals (CIs) were estimated to describe the strength of the relationship between Bsm I and PCa risk.

RESULTS

In this meta-analysis, 27 studies with 9,993 cases and 9,345 controls were included. The pooled results revealed that Bsm I polymorphism was not associated with PCa risk in the overall analysis. Moreover, no significant relationship was found in the subgroup analyses by ethnicities, genotyping methods, Hardy-Weinberg equilibrium status, and Gleason score. In the stratified analysis by the source of controls and clinical stages, controls of benign prostatic hyperplasia (BPH) seemed to be in the particular groups in which the association of PCa risk with Bsm I polymorphism was significant (Bb vs. bb: OR=0.643, 95% CI=0.436-0.949, p=0.026; BB/Bb vs. bb: OR=0.627, 95% CI=0.411-0.954, p=0.029; B vs. b: OR=0.715, 95% CI=0.530-0.965, p=0.029).

CONCLUSION

Our results suggest that Bsm I polymorphism is weakly associated with PCa risk, and hence, it cannot be considered as a predictor of the occurrence and development of PCa in clinical practice. Future studies with a larger number of samples are needed to verify our results.

Association of Vitamin D receptor Fok I polymorphism with the risk of prostate cancer: a meta-analysis

Several previous studies have been reported to examine the association between Vitamin D receptor (VDR) gene Fok I polymorphism and susceptibility to prostate cancer (PCa), however the results remain inconclusive. To provide a relatively comprehensive account of the association, we searched PubMed, Embase, CNKI, and Wanfang for eligible studies and carry out this meta-analysis. A total of 27 case-control studies with 10,486 cases and 10,400 controls were included. In the overall analysis, Fok I polymorphism was not significantly associated with the susceptibility to PCa. Subgroup analyses showed that significantly association was existed in Caucasian population, the subgroup of population-based controls and the stratified group with advanced tumor.These results indicate that the VDR Fok I polymorphism might be capable of causing PCa susceptibility and could be a promising target to forecast the PCa risk for clinical practice. However further well-designed epidemiologic studies are needed to confirm this conclusion.

Plasma 25-Hydroxyvitamin D Concentration and Risk of Islet Autoimmunity

We examined the association between plasma 25-hydroxyvitamin D [25(OH)D] concentration and islet autoimmunity (IA) and whether vitamin D gene polymorphisms modify the effect of 25(OH)D on IA risk. We followed 8,676 children at increased genetic risk of type 1 diabetes at six sites in the U.S. and Europe. We defined IA as positivity for at least one autoantibody (GADA, IAA, or IA-2A) on two or more visits. We conducted a risk set sampled nested case-control study of 376 IA case subjects and up to 3 control subjects per case subject. 25(OH)D concentration was measured on all samples prior to, and including, the first IA positive visit. Nine polymorphisms in VDR, CYP24A, CYP27B1, GC, and RXRA were analyzed as effect modifiers of 25(OH)D. Adjusting for HLA-DR-DQ and ancestry, higher childhood 25(OH)D was associated with lower IA risk (odds ratio = 0.93 for a 5 nmol/L difference; 95% CI 0.89, 0.97). Moreover, this association was modified by VDR rs7975232 (interaction P = 0.0072), where increased childhood 25(OH)D was associated with a decreasing IA risk based upon number of minor alleles: 0 (1.00; 0.93, 1.07), 1 (0.92; 0.89, 0.96), and 2 (0.86; 0.80, 0.92). Vitamin D and VDR may have a combined role in IA development in children at increased genetic risk for type 1 diabetes.

DHPLC Elution Patterns of VDR PCR Products Can Predict Prostate Cancer Susceptibility in African American Men

BACKGROUND/AIM

Denaturing high-performance liquid chromatography (DHPLC) is a technique that is used to detect mutations. The aim of the present study was to determine whether DHPLC elution patterns of vitamin D receptor (VDR) gene PCR products can serve as indicators of susceptibility to prostate cancer (PCa) risk.

MATERIALS AND METHODS

DNA samples of PCa cases and controls were screened for mutations and/or polymorphisms in coding exons of VDR gene using DHPLC analysis. Logistic regression, phi-coefficient (ϕ), and Backward Wald models were used to analyze the data.

RESULTS

Similar elution patterns of exons 1, 6, 7 and 9 along with higher prevalence of heteroduplex DNA were observed in PCa samples than in controls. Exons 4 and 8 had highly significant protective effects (p<0.05). Whereas, exons 5, 7, and 9 were perfectly positively correlated with PCa risk (ϕ=1), thus presenting candidate exons significantly associated with susceptibility to PCa.

CONCLUSION

DHPLC elution patterns of the selected exons could be useful to predict susceptibility to develop PCa.

Association of the vitamin D receptor FokI gene polymorphism with sex- and non-sex-associated cancers: A meta-analysis

Currently higher morbidity and mortality rates are observed in cancer diseases, especially sex-dependent cancers. A positive role of endogenous vitamin D concentration in cancer diseases has been reported in many publications. Furthermore, there has been observed a relationship between serum vitamin D and testosterone concentrations in an elderly Caucasian population carrying the vitamin D receptor FokI gene polymorphism. The aim of this study was to investigate whether the vitamin D receptor FokI polymorphism is associated with cancerogenesis in sex-dependent cancers. The MEDLINE and ResearchGate databases were used to search for articles up to January 2017, and 96 articles concerning the FokI polymorphism were chosen. Odds ratios with 95% confidence intervals were used to assess the strength of associations between polymorphisms of vitamin D receptor and cancer risk in the described populations. The fixed-effects model and the DerSimonian-Laird random-effects model (with weights based on the inverse variance) were used to calculate summary odds ratios, and both within- and between-study variation were considered. Generally, the F variant reduces the risk of cancer by 4% (odds ratio = 0.96, p value = 0.0057). This effect is particularly evident in female sex-associated cancers (odds ratio = 0.96, 95% confidence interval: 0.93-0.99, p value = 0.0259), but it is not observed in non-sex-associated cancers. Polymorphism FokI is associated with breast and ovarian cancers.

Updated analysis of vitamin D receptor gene FokI polymorphism and prostate cancer susceptibility

INTRODUCTION

Polymorphisms of the vitamin D receptor (VDR) gene have been investigated in various case-control studies to evaluate prostate cancer susceptibility; however, published data on the association between vitamin D receptor gene FokI polymorphism and prostate cancer risk are inconclusive.

MATERIAL AND METHODS

To assess the impact of vitamin D receptor gene FokI polymorphism, we performed a meta-analysis of eligible studies including 9,720 patients and 9,710 control subjects.

RESULTS

The overall results indicated no obvious association of this variant on prostate cancer risk. However, in subgroup analysis by ethnicity, positive associations existed in Caucasian descendents for allelic contrast (OR = 1.03, 95% CI: 1.00-1.06, p_{heterogeneity} = 0.552, p = 0.026) and the dominant genetic model (OR = 1.03, 95% CI: 1.00-1.05, p_{heterogeneity} = 0.856, p = 0.032). In the subgroup analysis by tumor stage, there was a significant association between this variant and advanced prostate cancer under the recessive genetic model (OR = 1.15, 95% CI: 1.01-1.32, p_{heterogeneity} = 0.469, p = 0.032). In the subgroup analysis by source of control, association of the VDR FokI polymorphism and prostate cancer susceptibility was also found in population-based studies under homozygote comparison and the recessive genetic model.

CONCLUSIONS

The VDR FokI polymorphism may contribute to the risk of developing prostate cancer in Caucasian and population-based studies. Further large, well-designed studies are warranted to confirm this conclusion in more detail.

Association between Serum 25-Hydroxy-Vitamin D and Aggressive Prostate Cancer in African American Men

African American men have higher incidence rates of aggressive prostate cancer, where high levels of calcium and serum vitamin D deficient levels play a role in the racial differences in incidence. In this study, we examined associations of serum vitamin D with aggressive prostate cancer to improve our understanding of higher susceptibility of aggressive disease in this racial cohort. From Howard University Hospital, 155 African American men with clinically-identified prostate cancer were identified; 46 aggressive cases, and 58 non-aggressive cases. Serum vitamin D was assessed from fasting blood samples, and total calcium intake was assessed using the Block Food Frequency Questionnaire. Vitamin D receptor polymorphisms from three different loci were genotyped; rs731236, rs1544410, and rs11568820. Multivariate logistic regression models were used to determine odds ratios (OR) and 95% confidence intervals (CI) comparing aggressive to non-aggressive prostate cancer. Vitamin D deficiency (<20 ng/mL) significantly increased risk of aggressive disease (OR: 3.1, 95% CI: 1.03–9.57, p-value = 0.04). Stratification by total calcium showed high calcium levels (≥800 mg/day) modified this association (OR: 7.3, 95% CI: 2.15–47.68, p-interaction = 0.03). Genetic variant rs11568820 appeared to increase the magnitude of association between deficient serum vitamin D and aggressive prostate cancer (OR: 3.64, 95% CI: 1.12–11.75, p-value = 0.05). These findings suggest that high incidence of aggressive prostate cancer risk in African American men may be due in-part to deficient levels of serum vitamin D. Other factors, including genetics, should be considered for future studies.

Meta-analysis on vitamin D receptor and cancer risk: focus on the role of TaqI, ApaI, and Cdx2 polymorphisms

Vitamin D plays a significant role in our health, including cancer incidence and mortality. Vitamin D receptor (VDR) single-nucleotide polymorphisms (SNPs) may affect its activity, influencing the risk of cancer. Several studies have investigated VDR SNPs, but the association with the risk of cancer is controversial. Here, we present a meta-analysis to assess the association of TaqI, ApaI, and Cdx2 SNPs with the risk of cancer. A systematic literature search was performed following a predefined protocol and using validated search strategies. This meta-analysis shows the summary odd ratio (SOR) overall, by cancer sites and by ethnicity. Up to January 2014, we identified 73 independent studies with 35 525 cases and 38 675 controls. The meta-analysis of Cdx2 gg versus GG showed a significant 12% increased risk for all cancers [SOR=1.12; 95% confidence interval (CI): 1.00–1.25]. The other SNPs analyzed did not show an overall significant association with the risk of cancer: SOR=0.98 (95% CI: 0.90–1.07) and 1.06 (95% CI: 0.95–1.19) for TaqI tt versus TT and ApaI aa versus AA, respectively. TaqI shows a significant 43% increased risk for colorectal cancer (SOR=1.43; 95% CI: 1.30–1.58 for tt vs. TT). Strong frequency variations are present among different ethnic groups. This meta-analysis showed an overall increased risk of cancer associated with Cdx2 SNP and a specific higher risk of colorectal cancer associated with the TaqI polymorphism. The VDR genotype might become more relevant when clustered in a specific haplotype, associated with other SNPs of genes involved in vitamin D metabolism, or for specific tumors and/or patient characteristics.

Role of vitamin D receptor gene Cdx2 and Apa1 polymorphisms in prostate cancer susceptibility: a meta-analysis

BACKGROUND

Vitamin D receptor (VDR) gene polymorphisms affect the risk of prostate cancer. However, studies investigating the relationship between VDR gene polymorphisms (Cdx2 and ApaI) and prostate cancer risk are equivocal. Therefore, we conducted a meta-analysis of all the studies to review the evidence available.

METHODS

A comprehensive search of PubMed, EMBASE, and ISI Web of Science for studies published until September 2015 was conducted. Odds ratios (ORs) and 95 % confidence intervals (CIs) were analyzed to determine the association between VDR Cdx2 and ApaI polymorphisms, and prostate cancer risk.

RESULTS

The meta-analysis included 10 studies involving 4979 cases and 4380 controls to analyze the VDR Cdx2 polymorphism. An additional 11 studies involving 2837 cases and 2884 controls were analyzed for the VDR ApaI polymorphism. Evidence failed to support the role of VDR Cdx2 and ApaI polymorphisms in prostate cancer. For Cdx2, the pooled OR was 1.11 (95 % CI = 0.93-1.33) for AA vs. GG genotypes, 0.97 (95 % CI = 0.88-1.06) for GA vs. AA genotypes, 0.99 (95 % CI = 0.91-1.08) for AA + GA vs. GG, and 1.12 (95 % CI = 0.95-1.31) for AA vs. GA + GG. No significant relationship was observed in any subgroup analysis based on ethnicity, controls, and Hardy-Weinberg equilibrium (HWE). ORs for the ApaI polymorphism were similar.

CONCLUSIONS

VDR Cdx2 and ApaI polymorphisms are not associated with prostate cancer. Additional evidence is required to confirm this conclusion.

Association of vitamin D receptor variants with clinical parameters in prostate cancer

Purpose

Prostate Cancer (PCa) is one of the most common cancers in men and its early detection can provide a high chance of cure. The detection of Vitamin D Receptor (VDR) gene polymorphisms may be useful as a molecular indicator of clinical outcome, once VDR is implicated in a wide variety of biological processes including modulation of the immune response and inhibition of cancer cell growth, angiogenesis and metastasis. In this study we explored the Single Nucleotide Polymorphisms (SNPs) FokI, BsmI, ApaI and TaqI, to evaluate the susceptibility locus for PCa and verify its correlation with clinical parameters.

Methods

VDR polymorphisms were detected by PCR followed by Restriction Fragment Length Polymorphism (PCR–RFLP). DNA samples were extracted from peripheral blood of 342 patients: 132 PCa, 41 Benign Prostatic Hyperplasia and 169 young healthy volunteers.

Results

Statistical analysis showed a noteworthy correlation among SNPs and clinical pathological features. CC genotype (TaqI) was correlated with the age at diagnosis (>58 years old), and GG (BsmI) was associated to lower Prostate-Specific Antigen (PSA) levels (<10 ng/mL). Moreover, when PCa patients were subgrouped, G allele (BsmI) significantly increased the estimated chance for PSA < 10 ng/mL, and GG/GG genotype (BsmI/ApaI) provided a 9.75 fold increased chance of patients with PCa to present lower PSA levels.

Conclusions

The polymorphisms of VDR gene showed a genotype-phenotype association and presented new correlations with different parameters as age and PSA levels.

Electronic supplementary material

The online version of this article (doi:10.1186/s40064-016-2009-8) contains supplementary material, which is available to authorized users.

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.

Meta-analysis of vitamin D-binding protein and cancer risk

BACKGROUND

Epidemiologic evidence supported a role for vitamin D and vitamin D receptor (VDR) polymorphisms in cancer risk. Beyond VDR, the biologic effects of vitamin D are mediated by the vitamin D-binding protein (DBP), a key protein in vitamin D metabolism. Furthermore, the gene encoding the DBP (GC, group-specific component) has an important role in the vitamin D pathway. Several studies investigated DBP serologic levels and GC polymorphisms in association with cancer risk with controversial results. Thus, we carried out a meta-analysis to investigate these associations.

METHODS

We included 28 independent studies concerning the following tumors: basal cell carcinoma, bladder, breast, colon-rectum, endometrium, liver, esophagus, stomach, melanoma, pancreas, prostate, and kidney. Through random-effect models, we calculated the summary odds ratios (SOR) for serum DBP and the GC polymorphisms rs2282679, rs12512631, rs7041, rs4588, rs17467825, rs1155563, and rs1352844.

RESULTS

We found a borderline decrease in cancer risk for subjects with high compared with low levels of DBP [SOR, 0.75; 95% confidence interval (CI), 0.56-1.00]. Dose-response meta-analysis indicates a nonsignificant decrease risk for an increase of 1,000 nmol/L of DBP (SOR, 0.96; 95% CI, 0.91-1.01). We found no significant alterations in cancer risk for subjects carrying any of the studied GC polymorphisms compared with wild-type subjects both in the main analysis and in analyses stratified by cancer type and ethnicity.

CONCLUSIONS

We found trends toward significance, suggesting a role of DBP in cancer etiology, which should be confirmed in further studies.

IMPACT

To our knowledge, this is the first study to investigate GC polymorphisms and DBP serologic levels in association with any type of cancer.

Association of vitamin D receptor gene polymorphisms and vitamin D levels with asthma and atopy in Cypriot adolescents: a case-control study

Background

Polymorphisms in the vitamin D receptor (VDR) gene have been studied in immune-related disorders either as independent contributors or in combination with vitamin D concentration. Vitamin D and VDR have been independently linked to asthma susceptibility. We investigated whether VDR variants were associated independently or in relation to vitamin D levels with asthma in Cypriot adolescents.

Methods

We studied 190 current wheezers, 69 of which were categorized as active asthmatics and 671 healthy controls. We determined three VDR genotypes (BsmI, TaqI, ApaI) and measured serum 25(OH)D levels. Logistic regression and stratified analyses by the presence of hypovitaminosis D (≤20 ng/ml) were used to evaluate the association of the VDR variants with asthma.

Results

The distribution of TaqI genotypes was significantly different between controls and current wheezers (p = 0.030) or active asthmatics (p = 0.014). The tt genotype was over-represented in wheezers (19.2 %) and asthmatics (21.3 %) compared to respective controls (12.9 %). No difference was observed between controls, current wheezers and active asthmatics in the genotypic distribution of BsmI and ApaI polymorphic sites. After stratification by the presence of hypovitaminosis D, a significant association was detected between tt genotype of TaqI polymorphism with wheezing (OR: 1.97, 95 % CI: 1.12, 3.46) and asthma (OR: 2.37, 95CI%: 1.02, 5.52) only in those with normal vitamin D levels (>20 ng/ml) but not in subjects with low vitamin D.

Conclusions

The minor TaqI genotype of VDR is associated with asthma in Cypriot adolescents. This polymorphism may contribute to asthma susceptibility primarily under conditions of normal vitamin D levels (>20 ng/ml).

Electronic supplementary material

The online version of this article (doi:10.1186/s40248-015-0025-0) contains supplementary material, which is available to authorized users.

Vitamin D, Cancer Risk, and Mortality

Antiproliferative effects of 1,25-dihydroxyvitamin D, the biologically active form of vitamin D, are well established in various cell types by influencing cell differentiation and decreasing cell proliferation, growth, invasion, angiogenesis, and metastasis. Several meta-analyses showed that low serum levels of 25(OH)D was associated with colorectal cancer and overall mortality, while the association with cancer mortality was less consistent. VDR is a crucial mediator for the cellular effects of vitamin D and conflicting data have been reported for most malignancies. Beyond VDR, the biological effects of vitamin D are mediated by the vitamin D-binding protein. The GC (group-specific component) gene, encoding DBP, is highly polymorphic and several polymorphisms were investigated in association with cancer development with controversial results. Vitamin D supplementation was found to be associated with a reduced risk of overall mortality, reviewing all published trials on healthy subjects, whereas the evidence of an effect on cancer risk and mortality is less clear. Furthermore, long-term health effects of high doses of vitamin D, extended duration of supplementation, and the association with different baseline vitamin D levels remain to be investigated. In summary, epidemiological and preclinical studies support the development of vitamin D as preventative and therapeutic anticancer agents, with significant associations especially found for low vitamin D status with overall mortality and cancer outcome, more than cancer incidence. However, a definitive conclusion cannot be drawn and only large randomized clinical trials, both in healthy subjects and in cancer patients, will allow to draw definitive conclusions on the effect of vitamin D supplementation on cancer risk, prognosis, and mortality.

Association of Vitamin D Receptor Cdx-2 Polymorphism With Cancer Risk: A Meta-Analysis

Vitamin D receptor (VDR) Cdx-2 polymorphism (rs11568820) has been indicated to be associated to cancer susceptibility. However, published studies reported mixed results. This meta-analysis was conducted to get a more accurate estimation of the association between Cdx-2 polymorphism and cancer risk.We identified 25 independent studies with a total of 34,018 subjects published prior to March 2015. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the susceptibility to cancer. Separate analyses were conducted on features of the population such as ethnicity, source of controls, and cancer types.Meta-analysis results showed that Cdx-2 polymorphism significantly increased cancer risk in the homozygous model in overall analysis. According to the further stratified analysis, significant association was found between Cdx-2 variant and cancer risk in American-Africans in the homozygous, recessive, and dominant comparison models. However, no significant associations were found in Caucasians and Asians. When stratified by different cancer types, significant association was observed between Cdx-2 variant and an increased risk of colorectal cancer in the homozygous, recessive, and dominant models. In addition, ovarian cancer susceptibility increased based on the homozygous and dominant comparison models.Our study indicated that VDR Cdx-2 polymorphism was associated with an increased cancer risk, particularly in American-Africans, colorectal, and ovarian cancers. However, other factors may impact on the association. Further multicenter studies are needed to confirm the effects of Cdx-2 polymorphism on cancer susceptibility.

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.

Associations of vitamin D pathway genes with circulating 25-hydroxyvitamin-D, 1,25-dihydroxyvitamin-D, and prostate cancer: a nested case-control study

PURPOSE

Vitamin D pathway single nucleotide polymorphisms (SNPs) are potentially useful proxies for investigating whether circulating vitamin D metabolites [total 25-hydroxyvitamin-D, 25(OH)D; 1,25-dihydroxyvitamin, 1,25(OH)2D] are causally related to prostate cancer. We investigated associations of sixteen SNPs across seven genes with prostate-specific antigen-detected prostate cancer.

METHODS

In a nested case-control study (within the ProtecT trial), we estimated odds ratios and 95 % confidence intervals (CIs) quantifying associations between SNPs and prostate cancer. Subgroup analyses investigated whether associations were stronger in men who had high/low sun exposure [a proxy for 25(OH)D]. We quantified associations of SNPs with stage (T1-T2/T3-T4) and grade (<7/≥7). Multiple variant scores included SNPs encoding proteins involved in 25(OH)D synthesis and metabolism.

RESULTS

We included 1,275 prostate cancer cases (141 locally advanced, 385 high grades) and 2,062 healthy controls. Vitamin D-binding protein SNPs were associated with prostate cancer (rs4588-A: OR 1.20, CI 1.01, 1.41, p = 0.04; rs7041-T: OR 1.19, CI 1.02, 1.38, p = 0.03). Low 25(OH)D metabolism score was associated with high (vs low) grade (OR 0.76, CI 0.63, 0.93, p = 0.01); there was a similar association of its component variants: rs6013897-A in CYP24A1 (OR 0.78, CI 0.60, 1.01, p = 0.06) and rs10877012-T in CYP27B1 (OR 0.80, CI 0.63, 1.02, p = 0.07). There was no evidence that associations differed by level of sun exposure.

CONCLUSION

We found some evidence that vitamin D pathway SNPs were associated with prostate cancer risk and grade, but not stage. There was no evidence of an association in men with deficient vitamin D (measured by having low sun exposure).

Evidence of differential effects of vitamin d receptor variants on epithelial ovarian cancer risk by predicted vitamin d status

INTRODUCTION

Experimental studies suggest vitamin D inhibits ovarian carcinogenesis. Yet, epidemiologic studies of ovarian cancer risk and lifestyle correlates of vitamin D status, plasma 25-hydroxyvitamin D [25(OH)D], or vitamin D receptor (VDR) variants have been inconsistent.

OBJECTIVE

To evaluate VDR genetic associations by high vs. low predicted 25(OH)D, scores derived from known determinants of plasma 25(OH)D. To assess ovarian cancer associations with variants identified in genome-wide association studies (GWAS) of plasma 25(OH)D.

METHODS

We genotyped up to seven VDR and eight 25(OH)D GWAS variants in the Nurses' Health Studies (562 cases, 1,553 controls) and New England Case-Control study (1,821 cases, 1,870 controls). We estimated haplotype scores using expectation-maximization-based algorithms. We used unconditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CI). We combined study results using DerSimonian and Laird meta-analysis.

RESULTS

Ovarian cancer risk increased per A allele of rs7975232 (VDR; OR = 1.12, 95% CI = 1.01-1.25) among all women. When stratified by predicted 25(OH)D, ovarian cancer was associated with rs731236 (VDR; per C allele OR = 1.31) and rs7975232 (OR = 1.38) among women with high predicted 25(OH)D, but not among women with low levels (P ≤ 0.009). We also observed heterogeneity by predicted 25(OH)D for the ovarian cancer association with VDR 3' end haplotypes (P = 0.009). Of 25(OH)D-associated GWAS loci, rs7041 was associated with reduced ovarian cancer risk (per T allele OR = 0.92, 95% CI = 0.85-0.99), which did not differ by predicted 25(OH)D status.

CONCLUSION

Our study suggests an influence of VDR 3' end variants on ovarian cancer risk may be observed in women with high predicted 25(OH)D, which remained even after taking multiple comparisons into consideration. Future studies are needed to confirm our results and explore further the relation between vitamin D exposure, genetic variants, and ovarian cancer risk.

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.

Vitamin D receptor polymorphism FokI and cancer risk: a comprehensive meta-analysis

Numerous studies investigated the associations of VDR polymorphisms with various types of cancer, suggesting an influence on cancer risk. FokI is one of the most frequently analysed polymorphisms but the results from single studies are contradictory. We performed a meta-analysis looking at the association between the FokI and all cancer sites and investigating sources of heterogeneity. We identified 77 independent studies up to April 2014. We presented the summary odds ratios (SORs) by cancer sites, ethnicity and study features. We found a significant association between FokI and ovarian cancer for ff genotype versus FF with no heterogeneity: SOR = 1.20 (95% CI: 1.02-1.41, I (2) = 0%). Moreover, we found a significant increased risk of any cancer: SOR = 1.08 (95% CI: 1.01-1.16, I (2) = 58%). A significant increased risk of any cancer is confirmed among Caucasian, among studies in Hardy-Weinberg equilibrium and nested case-control studies. Furthermore, among studies in Hardy-Weinberg equilibrium, skin cancer was found significantly associated with FokI: SOR = 1.24 (95% CI: 1.01-1.54; I (2) = 24%) for ff versus FF. The estimated number of cases attributable to ff genotype is 4221 for ovarian cancer and 52858 for skin cancer worldwide each year. No indication for publication bias was found for any cancer site. In conclusion, we found an overall significant association of FokI polymorphism with any cancer, with differential effect by ethnicity. In particular, the summary estimates indicate an increase risk for ovarian and skin cancer for ff versus FF. However, other factors may act modifying the association, and further studies are needed to clarify the impact on cancer risk.

BsmI polymorphism of vitamin D receptor gene and cancer risk: a comprehensive meta-analysis

The VDR gene is an important regulator of the vitamin D pathway, and the role of some of its polymorphisms on cancer risk was previously investigated. A trend of cancer risk reduction with the VDR BsmI B allele was observed for many cancer sites. We performed a comprehensive meta-analysis to investigate the role of VDR BsmI polymorphism on cancer risk, even according to different ethnicities. Summary odds ratios (SORs) were calculated with random-effects models and maximum likelihood estimation. We categorized studies into three groups ("moderate", "high" and "very high confidence") according to departure from Hardy-Weinberg equilibrium in controls, reported minor allele frequency and genotyping quality controls. The meta-analysis included 73 studies with 45,218 cases and 52,057 controls. We found a significant 6-7% reduction of cancer risk at any site respectively for carriers of Bb genotype (SOR; 95%CI: 0.94; 0.90-0.99) and for carriers of BsmI BB genotype (SOR; 95%CI: 0.93; 0.89-0.98) compared to bb carriers, and they remain statistically significant when we restricted the analysis to at least "high confidence" studies. For skin cancer, a significant risk reduction was observed for Bb carriers (SOR; 95%CI: 0.86; 0.76-0.98). We also found a significant reduction of colorectal cancer risk for BB and Bb+BB genotypes carriers, but these SORs were no more significant when we restricted the analysis to studies with "high confidence". When the analysis was stratified by ethnicity, we still observed a significant decreased risk for both Bb and BB compared to bb genotype among Caucasians: SORs (95%CI) for any cancer site were 0.97 (0.93-1.00) and 0.95 (0.91-0.99), respectively. Among other ethnic groups the inverse association was still present, but did not reach statistical significance. In conclusion, we suggest a weak effect of BsmI B allele in reducing cancer risk at any site, especially of the skin.

In older men, lower plasma 25-hydroxyvitamin D is associated with reduced incidence of prostate, but not colorectal or lung cancer

CONTEXT AND OBJECTIVE

Prostate, colorectal and lung cancers are common in men. In this study, we aimed to determine whether vitamin D status is associated with the incidence of these cancers in older men.

DESIGN

Prospective cohort study.

SETTING AND PARTICIPANTS

4208 older men aged 70-88 years in Perth, Western Australia.

MAIN OUTCOME MEASURES

Plasma 25-hydroxyvitamin D [25(OH)D] concentration was measured by immunoassay. New diagnoses of prostate, colorectal and lung cancers were determined via electronic record linkage.

RESULTS

During a mean follow-up of 6.7±1.8 years, there were 315, 117 and 101 new diagnoses of prostate, colorectal and lung cancer. In multivariate competing risks proportional hazards models, every 10 nmol/l decrease in 25(OH)D concentration was associated with a 4% reduction in prostate cancer incidence (sub-hazard ratio [SHR] 0.96, 95% confidence interval [CI] 0.92-1.00). Every halving of 25(OH)D concentration was associated with a 21% reduction in incident prostate cancer in multivariate analysis (SHR 0.79, 95% CI 0.63-0.99). Following exclusion of prostate cancer cases diagnosed within 3 years of blood sampling, low 25(OH)D <50 nmol/l was associated with lower incident prostate cancer, and higher 25(OH)D >75 nmol/l was associated with higher incidence, when compared to the reference range 50-75 nmol/l, respectively (p = 0.027). Significant associations were also observed when 25(OH)D was modeled as a quantitative variable. No associations were observed between plasma 25(OH)D concentration with incidence of colorectal or lung cancer.

CONCLUSION

Lower levels of vitamin D may reduce prostate cancer risk in older men. By contrast, levels of vitamin D did not predict incidence of colorectal or lung cancers. Further studies are needed to determine whether a causal relationship exists between vitamin D and prostate cancer in ageing men.

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.

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.

Polymorphisms in the vitamin D Receptor (VDR) and the risk of ovarian cancer: a meta-analysis

The vitamin D receptor (VDR) principally mediates the anticancer activities of vitamin D. Various epidemiological studies have investigated the associations of VDR gene polymorphisms with ovarian cancer; however, the results have been inconclusive. In the current study, we evaluated, in a meta-analysis, the association of five common single nucleotide polymorphisms (SNPs) in the VDR gene (ApaI, BsmI, Cdx-2, FokI, and TaqI) with the risk of ovarian cancer. Six eligible studies, with a total of 4,107 cases and 6,661 controls, which evaluated the association of these variants and ovarian cancer risk, were identified from the MEDLINE and PubMed databases. The meta-analysis indicated that FokI was associated with an increased ovarian cancer risk, with a pooled odds ratio (OR) of 1.10 [95% confidence intervals (95% CI) = 1.00-1.20] for CT heterozygotes and 1.16 (95% CI = 1.02-1.30) for TT homozygotes relative to common CC carriers. Carriers of the T allele (also known as the f allele) showed an 11% (pooled OR = 1.11, 95% CI = 1.02-1.21; TT/CT vs. CC) increased risk of ovarian cancer relative to CC carriers. For FokI, no significant heterogeneity between the studies was found (I(2) = 0%, P = 0.62 for the Q test). There was no statistically significant association between the other four variants (ApaI, BsmI, Cdx-2 and TaqI) and risk of ovarian cancer. These data indicate that the polymorphism FokI on the VDR is a susceptibility factor for ovarian cancer. Nevertheless, more studies are warranted to elucidate the underlying mechanisms of the VDR in development of ovarian cancer.

Sunlight, vitamin D and the prevention of cancer: a systematic review of epidemiological studies

The number of studies reporting beneficial effects of sunlight and vitamin D on several types of cancer with a high mortality rate is growing rapidly. Present health recommendations on sun exposure are mainly based on the increased risks for skin cancer. We reviewed all published studies concerning cancer and sun exposure and vitamin D, respectively, excluding those about skin cancer. Most identified ecological, case-control and prospective studies on the incidence and mortality of colorectal, prostate, breast carcinoma and non-Hodgkin lymphoma reported a significantly inverse association with sun exposure. The results of the included studies on the association between cancer risk and vitamin D were much less consistent. Only those studies that prospectively examined the 25-hydroxyvitamin D serum levels in relation to risk of colorectal cancer are homogeneous: they all reported inverse associations, although not all reaching statistical significance. The results of the intervention studies are suggestive of a protective role of high doses of vitamin D in cancer, but they have been criticized in the literature. We, therefore, conclude that there is accumulating evidence for sunlight as a protective factor for several types of cancer. The same conclusion can be made concerning high vitamin D levels and the risk of colorectal cancer. This evidence, however, is not conclusive, because the number of (good quality) studies is still limited and publication biases cannot be excluded. The discrepancies between the epidemiological evidence for a possible preventive effect of sunlight and vitamin D and the question of how to apply the findings on the beneficial effects of sunlight to (public) health recommendations are discussed.

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.

Current progress in using vitamin D and its analogs for cancer prevention and treatment

Vitamin D has long been known for its physiological role in mineral homeostasis through its actions on the intestines, kidneys, parathyroid glands and bone. However, recent observations of antiproliferative, prodifferentiating and antiangiogenic effects elicited by the bioactive form of vitamin D (1,25[OH](2)D(3)) in a broad range of cancers is less well understood. Here, we review the increasing epidemiological and experimental evidence that supports the development of 1,25(OH)(2)D(3) and vitamin D analogs as preventative and therapeutic anticancer agents. Furthermore, this review summarizes the preclinical and clinical studies of vitamin D and its analogs over the past decade, indicating the current problems of dose-limiting toxicity from hypercalcemia and large interpatient variability in pharmacokinetics. A better understanding of how genetic variants influence vitamin D status should not only improve cancer risk predictions, but also promote the development of vitamin D analogs with more specific actions to improve therapeutic outcomes.

The role of vitamin D in pregnancy and lactation: emerging concepts

Pregnancy is a critical time in the lifecycle of a woman where she is responsible not only for her own well-being, but also that of her developing fetus, a process that continues during lactation. Until recently, the impact of vitamin D status during this period had not been fully appreciated. Data regarding the importance of vitamin D in health have emerged to challenge traditional dogma, and suggest that vitamin D - through its effect on immune function and surveillance - plays a role beyond calcium and bone metabolism on the health status of both the mother and her fetus. Following birth, this process persists; the lactating mother continues to be the main source of vitamin D for her infant. Thus, during both pregnancy and lactation, maternal deficiency predicts fetal and infant deficiency; the significance of this is just beginning to be understood and will be highlighted in this review.

Vitamin D and its role during pregnancy in attaining optimal health of mother and fetus

Despite its discovery a hundred years ago, vitamin D has emerged as one of the most controversial nutrients and prohormones of the 21st century. Its role in calcium metabolism and bone health is undisputed but its role in immune function and long-term health is debated. There are clear indicators from in vitro and animal in vivo studies that point to vitamin D's indisputable role in both innate and adaptive immunity; however, the translation of these findings to clinical practice, including the care of the pregnant woman, has not occurred. Until recently, there has been a paucity of data from randomized controlled trials to establish clear cut beneficial effects of vitamin D supplementation during pregnancy. An overview of vitamin metabolism, states of deficiency, and the results of recent clinical trials conducted in the U.S. are presented with an emphasis on what is known and what questions remain to be answered.

Calcium intake and prostate cancer among African Americans: effect modification by vitamin D receptor calcium absorption genotype

High dietary intake of calcium has been classified as a probable cause of prostate cancer, although the mechanism underlying the association between dietary calcium and prostate cancer risk is unclear. The vitamin D receptor (VDR) is a key regulator of calcium absorption. In the small intestine, VDR expression is regulated by the CDX-2 transcription factor, which binds a polymorphic site in the VDR gene promoter. We examined VDR Cdx2 genotype and calcium intake, assessed by a food frequency questionnaire, in 533 African-American prostate cancer cases (256 with advanced stage at diagnosis, 277 with localized stage) and 250 African-American controls who participated in the California Collaborative Prostate Cancer Study. We examined the effects of genotype, calcium intake, and diet-gene interactions by conditional logistic regression. Compared with men in the lowest quartile of calcium intake, men in the highest quartile had an approximately twofold increased risk of localized and advanced prostate cancer (odds ratio [OR] = 2.20, 95% confidence interval [CI] = 1.40, 3.46), with a significant dose-response. Poor absorbers of calcium (VDR Cdx2 GG genotype) had a significantly lower risk of advanced prostate cancer (OR = 0.41, 95% CI = 0.19, 0.90). The gene-calcium interaction was statistically significant (p = 0.03). Among men with calcium intake below the median (680 mg/day), carriers of the G allele had an approximately 50% decreased risk compared with men with the AA genotype. These findings suggest a link between prostate cancer risk and high intestinal absorption of calcium.

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.

Vitamin D receptor protein expression in tumor tissue and prostate cancer progression

PURPOSE

Data suggest that circulating 25-hydroxyvitamin D [25(OH)D] interacts with the vitamin D receptor (VDR) to decrease proliferation and increase apoptosis for some malignancies, although evidence for prostate cancer is less clear. How VDR expression in tumor tissue may influence prostate cancer progression has not been evaluated in large studies.

PATIENTS AND METHODS

We examined protein expression of VDR in tumor tissue among 841 patients with prostate cancer in relation to risk of lethal prostate cancer within two prospective cohorts, the Physicians' Health Study and Health Professionals Follow-Up Study. We also examined the association of VDR expression with prediagnostic circulating 25(OH)D and 1,25-dihydroxyvitamin D levels and with two VDR single nucleotide polymorphisms, FokI and BsmI.

RESULTS

Men whose tumors had high VDR expression had significantly lower prostate-specific antigen (PSA) at diagnosis (P for trend < .001), lower Gleason score (P for trend < .001), and less advanced tumor stage (P for trend < .001) and were more likely to have tumors harboring the TMPRSS2:ERG fusion (P for trend = .009). Compared with the lowest quartile, men whose tumors had the highest VDR expression had significantly reduced risk of lethal prostate cancer (hazard ratio [HR], 0.17; 95% CI, 0.07 to 0.41). This association was only slightly attenuated after adjustment for Gleason score and PSA at diagnosis (HR, 0.33; 95% CI, 0.13 to 0.83) or, additionally, for tumor stage (HR, 0.37; 95% CI, 0.14 to 0.94). Neither prediagnostic plasma vitamin D levels nor VDR polymorphisms were associated with VDR expression.

CONCLUSION

High VDR expression in prostate tumors is associated with a reduced risk of lethal cancer, suggesting a role of the vitamin D pathway in prostate cancer progression.

Prediagnostic plasma vitamin D metabolites and mortality among patients with prostate cancer

BACKGROUND

Laboratory evidence suggests that vitamin D might influence prostate cancer prognosis.

METHODOLOGY/PRINCIPAL FINDINGS

We examined the associations between prediagnostic plasma levels of 25(OH)vitamin D [25(OH)D] and 1,25(OH)(2) vitamin D [1,25(OH)(2)D] and mortality among 1822 participants of the Health Professionals Follow-up Study and Physicians' Health Study who were diagnosed with prostate cancer. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of total mortality (n = 595) and lethal prostate cancer (death from prostate cancer or development of bone metastases; n = 202). In models adjusted for age at diagnosis, BMI, physical activity, and smoking, we observed a HR of 1.22 (95% CI: 0.97, 1.54) for total mortality, comparing men in the lowest to the highest quartile of 25(OH)D. There was no association between 1,25(OH)(2)D and total mortality. Men with the lowest 25(OH)D quartile were more likely to die of their cancer (HR: 1.59; 95% CI: 1.06, 2.39) compared to those in the highest quartile (P(trend) = 0.006). This association was largely explained by the association between low 25(OH)D levels and advanced cancer stage and higher Gleason score, suggesting that these variables may mediate the influence of 25(OH)D on prognosis. The association also tended to be stronger among patients with samples collected within five years of cancer diagnosis. 1,25(OH)(2)D levels were not associated with lethal prostate cancer.

CONCLUSIONS/SIGNIFICANCE

Although potential bias of less advanced disease due to more screening activity among men with high 25(OH)D levels cannot be ruled out, higher prediagnostic plasma 25(OH)D might be associated with improved prostate cancer prognosis.

Meta-analysis of observational studies of serum 25-hydroxyvitamin D levels and colorectal, breast and prostate cancer and colorectal adenoma

Epidemiological studies have suggested a reduced risk of several cancers associated with high vitamin D status. We performed a systematic review with meta-analyses of observational studies of serum 25-hydroxyvitamin D level and colorectal, breast and prostate cancer and colonic adenoma. The literature of December 2009 was searched without language restriction. The meta-regression analysis was done to compute dose-response effects. Because in case-control studies, serum 25-hydroxyvitamin D level is measured after the diagnosis of cancer, separate analyses for case-control and prospective studies were done. We identified 35 independent studies. The seven studies on colorectal adenomas were heterogeneous in terms of endpoint and control for major confounding factors, and we did not perform a meta-analysis of these data. The summary relative risk (SRR) and (95% confidence interval) for a 10 ng/ml increase in serum 25-hydroxyvitamin D was 0.85 (0.79; 0.91) for colorectal cancer (2,630 cases in 9 studies); 0.89 (0.81;0.98) for breast cancer (6,175 cases in 10 studies); and 0.99 (0.95;1.03) for prostate cancer (3,956 cases in 11 studies). For breast cancer, case-control studies (3,030 cases) had major limitations and obtained SRR of 0.83 (0.79; 0.87) whereas SRR of prospective studies (3,145 cases) was 0.97 (0.92; 1.03). For colorectal and breast cancer, differences between cases and controls in the season of blood draw or in overweight/obesity or physical inactivity could not explain the results. In conclusion, a consistent inverse relationship between serum 25-hydroxyvitamin D levels and colorectal cancer was found. No association was found for breast and prostate cancer.

Associations of circulating and dietary vitamin D with prostate cancer risk: a systematic review and dose-response meta-analysis

OBJECTIVE

We systematically reviewed and meta-analyzed literature examining associations of vitamin D (dietary intake, circulating 25-hydroxy-vitamin-D (25(OH)D), and 1,25-dihydroxy-vitamin-D (1,25(OH)(2)D) concentrations) with prostate cancer.

METHODS

We searched over 24,000 papers from seven electronic databases (to October 2010) for exposures related to vitamin D. We conducted dose-response random-effects meta-analyses pooling the log odds ratio (OR) and 95% confidence intervals (CI) per change in natural units of each exposure. The I(2) statistic quantified between-study variation due to heterogeneity.

RESULTS

Twenty-five papers were included. In prospective studies, the OR per 1,000 IU increase in dietary intake was 1.14 (6 studies; CI: 0.99, 1.31; I (2) = 0%) for total prostate cancer and 0.93 (3 studies; 0.63, 1.39; I (2) = 25%) for aggressive prostate cancer. Five case-control studies examined dietary intake, but there was a high degree of inconsistency between studies (I (2) = 49%). The OR per 10 ng/mL increase in 25(OH)D was 1.04 (14 studies; 0.99, 1.10; I (2) = 0%) for total prostate cancer and 0.98 (6 studies; 0.84, 1.15; I (2) = 32%) for aggressive prostate cancer. The OR per 10 pg/mL increase in 1,25(OH)(2)D was 1.00 (7 studies; 0.87, 1.14; I (2) = 41%) for total prostate cancer and 0.86 (2 studies; 0.72, 1.02; I (2) = 0%) for aggressive prostate cancer.

CONCLUSION

Published literature provides little evidence to support a major role of vitamin D in preventing prostate cancer or its progression.