Polymorphisms in the vitamin D receptor and risk of ovarian cancer in four studies

Lower vitamin D levels and VDR variants are risk factors for breast cancer: an updated meta-analysis

Inadequate vitamin D levels and vitamin D variants have been shown to be associated with breast cancer (BC), however the results are inconsistent. To reach a definitive conclusion the present meta-analysis was conducted. When compared to healthy controls, BC patients had reduced vitamin D levels (standard difference in means = -0.564, p = 0.003). The meta-analysis revealed that the FokI mutation was linked with an increased BC susceptibility (CC vs. TT: OR = 1.107, p = 0.001, CC vs. TC + TT: OR = 1.114, p = 0.020). There was no role of other VDR variants (BsmI, TaqI, and ApaI). FokI mutation and diminished vitamin D increase the likelihood of developing BC.

The association between single nucleotide polymorphisms and ovarian cancer risk: A systematic review and network meta-analysis

BACKGROUND

The relationship between single nucleotide polymorphisms (SNPs) and ovarian cancer (OC) risk remains controversial. This systematic review and network meta-analysis was aimed to determine the association between SNPs and OC risk.

METHODS

Several databases (PubMed, EMBASE, China National Knowledge Infrastructure, Wanfang databases, China Science and Technology Journal Database, and China Biology Medicine disc) were searched to summarize the association between SNPs and OC published throughout April 2021. Direct meta-analysis was used to identify SNPs that could predict the incidence of OC. Ranking probability resulting from network meta-analysis and the Thakkinstian's algorithm was used to select the most appropriate gene model. The false positive report probability (FPRP) and Venice criteria were further tested for credible relationships. Subgroup analysis was also carried out to explore whether there are racial differences.

RESULTS

A total of 63 genes and 92 SNPs were included in our study after careful consideration. Fok1 rs2228570 is likely a dominant risk factor for the development of OC compared to other selected genes. The dominant gene model of Fok1 rs2228570 (pooled OR = 1.158, 95% CI: 1.068-1.256) was determined to be the most suitable model with a FPRP <0.2 and moderate credibility.

CONCLUSIONS

Fok1 rs2228570 is closely linked to OC risk, and the dominant gene model is likely the most appropriate model for estimating OC susceptibility.

Vitamin D in gynecological diseases

BACKGROUND

Most reproductive system studies suggest the protective effects of vitamin D, but vitamin D deficiency and insufficiency are growing global health issues. The present study investigates the association between vitamin D deficiency/insufficiency and gynecologic diseases to identify illness risks at different serum vitamin D levels in Taiwan.

METHODS

A total of 7699 female adults aged ≥20 years with results for both serum vitamin D and gynecologic-associated diseases were drawn from the Taiwan MJ cohort. We analyzed the correlation between serum vitamin D levels and results from reproductive system evaluations, including history of dysmenorrhea, results of Pap smear, high-risk human papillomavirus (HPV) infection of the cervix, mammography, and ultrasound of breast and pelvis.

RESULTS

Over 80% of participants showed vitamin D deficiency/insufficiency. Participants with abnormal Pap smear results, high-risk HPV infection, and history of dysmenorrhea showed significantly lower levels of serum vitamin D (p < 0.001-0.05). Serum vitamin D deficiency was significantly associated with positive high-risk HPV infection of the cervix (p < 0.05) and dysmenorrhea (p < 0.001). After controlling for age as a confounding variable for each gynecologic disease, level of serum vitamin D was significantly associated with abnormal breast ultrasound (odds ratio = 0.724) and uterus ultrasound (odds ratio = 0.673 - 0.8), and dysmenorrhea (odds ratio = 0.829).

CONCLUSION

Associations were found between vitamin D deficiency and endometriosis, uterine myoma, dysmenorrhea, abnormal Pap smear results, and high-risk HPV infection of the cervix. Therefore, vitamin D supplements may present a cost-effective benefit for the prevention and treatment of gynecologic diseases, and thus reduction of healthcare expenditures.

Vitamin D receptor gene polymorphisms and uterine fibroid incidence in Caucasian women

INTRODUCTION

Uterine fibroids (UFs) are benign tumors which are derived from the smooth muscle cells of the uterus. Recent studies have demonstrated that the development of UFs can be particularly related to vitamin D and its receptor. Vitamin D comprises a group of fat-soluble steroid compounds which exert powerful, pleiotropic effects all over the human body. These actions are mediated by a specific type of receptor - vitamin D receptor (VDR). Recent findings have focused on the possible role of VDR genetic variations in the development of several types of diseases, e.g. autoimmune system diseases, various cancers and infections.

MATERIAL AND METHODS

The aim of the study was to evaluate the association between rs731236, rs1544410, and rs2228570 polymorphisms in the VDR (vitamin D receptor) gene and the incidence of UFs in Caucasian women. A total of 197 patients (114 fibroid-positive and 83 controls) were included in this retrospective cohort study. VDR gene polymorphisms rs731236 (TaqI), rs1544410 (BsmI) and rs2228570 (FokI) were determined using TaqMan and Simple Probes.

RESULTS

No statistically significant differences in the occurrence of selected VDR polymorphisms were observed between UF-positive women and healthy controls.

CONCLUSIONS

We found no association between rs731236, rs1544410, and rs2228570 VDR polymorphisms and UF incidence in Caucasian women. Larger sample size and multi-ethnic studies are necessary to investigate the matter further.

Ethnicity as modifier of risk for Vitamin D receptors polymorphisms: Comprehensive meta-analysis of all cancer sites

Vitamin D receptors polymorphisms are found to be associated with several cancers. Since their prevalence vary across ethnicities and ethnicity itself seems to influence the cancer risk, a comprehensive meta-analysis was performed to investigate the role of VDR Fok1, Bsm1, Taq1, Apa1, Cdx2 and cancer risk at specific organ sites. Odds ratios, calculated with random-effects models, summarized one-hundred-ninety-two independent studies for twenty-two cancer sites. Evidence was provided that Fok1, Bsm1, Cdx2, Apa1 and Taq1 are linked to cancer susceptibility for colorectal, lung, ovarian, skin, multiple myeloma and brain cancer. Stratifying by ethnicity, some differences were found, partially explained by minor allele frequency (MAF), for colorectal cancer, ovarian and prostate cancer in Caucasian and prostate cancer in Asian populations. In summary, ethnicity may be a modifier of cancer risk, in particular for hormone dependent cancers and it should be considered evaluating the effect of VDR on cancer risk.

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.

Vitamin D and Ovarian Cancer: Systematic Review of the Literature with a Focus on Molecular Mechanisms

Vitamin D is a lipid soluble vitamin involved primarily in calcium metabolism. Epidemiologic evidence indicates that lower circulating vitamin D levels are associated with a higher risk of ovarian cancer and that vitamin D supplementation is associated with decreased cancer mortality. A vast amount of research exists on the possible molecular mechanisms through which vitamin D affects cancer cell proliferation, cancer progression, angiogenesis, and inflammation. We conducted a systematic review of the literature on the effects of vitamin D on ovarian cancer cell.

Investigation of Interaction between Vitamin D Receptor Gene Polymorphisms and Environmental Factors in Early Childhood Caries in Chinese Children

Background

Early childhood caries is a multifactorial disease involving interactions between genetic and environmental risk factors. The aim of this study was to examine the effects of vitamin D receptor (VDR) gene polymorphisms and gene-environment interactions on the etiology of, and susceptibility to, caries in Chinese children aged 3-5 years.

Methods

Children (n = 549) were divided into three groups according to caries risk: high (decayed, missing, filled teeth (dmft) index > 4; n = 148), moderate (dmft = 1-4; n = 156), and caries-free (n = 245). A questionnaire was designed to collect demographic information, dietary habits, and oral hygiene practices, and dental plaque samples were collected to test acidogenic activity of bacteria. Genomic DNA was extracted from the buccal mucosa, and the VDR polymorphisms rs7975232, rs1544410, rs11568820, rs10735810, and rs731236 were genotyped using TaqMan assays.

Results

There were no differences among the caries risk groups in frequencies of the rs7975232, rs731236, rs1544410, or rs11568820 polymorphisms (χ ² test, P > 0.05); however, the frequency of the rs10735810 CC genotype was clearly higher in the high caries risk group than in the control and moderate caries risk groups (39.2%, 25.6%, and 30.6%, respectively; χ ² test, P=0.028). In multivariate analysis of genotypes and behavioral factors, rs7975232, rs731236, rs1544410, rs11568820, and rs10735810 were not associated with deciduous tooth decay (χ ² test, P > 0.05).

Conclusion

We conclude that these VDR polymorphisms cannot be used as markers for identification of Chinese children at increased risk of dental caries, when combined with environmental factors. Future studies are needed to replicate these initial findings and better assess the risk of caries in deciduous teeth.

The role of vitamin D in ovarian cancer: epidemiology, molecular mechanism and prevention

Vitamin D is a fat-soluble prohormone best known for its role in maintaining calcium homeostasis. Large numbers of epidemiological studies have shown that vitamin D plays an important role in cancer prevention by regulating cellular proliferation and metabolism. Studies of the cellular mechanism of vitamin D in ovarian cancer strongly suggest that it exhibits protective and antitumorigenic activities through genomic and nongenomic signal transduction pathways. These results indicate that vitamin D deficiency results in an increase in the risk of developing ovarian cancer and that vitamin supplements may potentially be an efficient way of preventing cancer. Consequently, this review describes the epidemiology, molecular mechanism and evidence linking vitamin D deficiency to ovarian cancer.

Do genetic polymorphisms of the vitamin D receptor contribute to breast/ovarian cancer? A systematic review and network meta-analysis

BACKGROUND

To identify the most suitable genetic model for detecting the risk of breast cancer (BC)/ovarian cancer (OC) in specific populations.

METHODS

Databases were searched for related studies published up to October 2017. First, VDR genetic polymorphisms were compared in patients with and without cancer. Second, a network meta-analysis was used to reveal the relation between VDR genetic polymorphisms with disease outcomes. Subgroup analyses and a meta-regression were performed according to cancer types, ethnicity and genotypic method. The study is registered in PROSPERO with an ID: CRD42017075505.

RESULTS

Forty-five studies were eligible, which included 65,754 patients and 55 clinical analyses. Of genetic models, results suggested that the recessive model with the CDX2 polymorphism predicted the risk of BC in all cases. The recessive polymorphism model with the rs2228570 (FokI) polymorphism seemed to the best predictor of BC in Caucasian patients, whereas the homozygote model with the CDX2 polymorphism appeared to best predict BC in African-American patients. The homozygote model with the rs2228570 (FokI) polymorphism model appeared to detect the risk of OC in all cases, whereas the heterozygote model with the rs1544410 (BsmI) polymorphism seemed to detect the risk of OC in Caucasian patients.

CONCLUSIONS

By detecting the risk of BC, the recessive model with the rs2228570 (FokI) polymorphism is likely the best genetic model in Caucasian patients, and the homozygote model with the CDX2 polymorphism appears to be best genetic model in African-American patients. Moreover, for detecting clinical risk of OC, heterozygote models with the rs1544410 (BsmI) polymorphism is likely the best genetic model for detecting the risk of OC in Caucasian patients.

Associations between serum vitamin D and the risk of female reproductive tumors: A meta-analysis with trial sequential analysis

BACKGROUND

Female reproductive tumors are common with high morbidity and mortality worldwide; however, the association between gynecological tumors and serum vitamin D is controversial. The aim of this meta-analysis was to evaluate the relationship between insufficiency of serum vitamin D and the occurrence of benign and malignant gynecological tumors.

METHODS

Studies from inception to June 2017 were searched in the electronic databases: National Library of Medicine (PubMed), Web of Science (Clerivate), and Cochrane Database of Systematic Reviews (Cochrane Library, CDSR) by 2 investigators independently. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using a random-effects model. STATA 12.0 Software and Trial Sequential Analysis (TSA) software were applied for data analyses.

RESULTS

Overall, 8 studies (including 2391 patients and 5798 patients with and without female reproductive tumors, respectively) were eligible for the present meta-analysis. In the subsequent meta-analysis, the occurrence of vitamin D deficiency in the case and control groups were 52.36% and 48.70%, respectively; women with female reproductive benign and malignant tumors were 55.57% and 50.59%, respectively. Although, no conclusive association was found between vitamin D deficiency and female reproductive tumors (OR, 1.05; 95% CI, 0.85-1.31); vitamin D deficiency may be a risk factor of malignant female reproductive neoplasm, as shown by the pooled OR (95% CI):1.17 (1.02-1.33). Furthermore, based on the OR values, association of vitamin D insufficiency with disease type, study location, number of patients, and methods for detecting CLA was observed. Similar results in the sensitivity analysis were observed. TSA showed that the cumulative Z-curve crossed the traditional boundary line, rather than crossing the trial sequential monitoring boundary. However, the cumulative information failed to reach the required information size.

CONCLUSIONS

Currently, vitamin D deficiency appears to be a common issue in females, and there may be an urgent need to improve the level of vitamin D. Furthermore, vitamin D deficiency may be a non-negligible risk factor of malignant female reproductive neoplasm. Undoubtedly, more trials are required in the future according to TSA.

Vitamin D receptor rs2228570 polymorphism and susceptibility to ovarian cancer: An updated meta-analysis

AIM

The FokI polymorphism (C>T, rs2228570) of the vitamin D receptor gene is a coding nonsynonymous single nucleotide polymorphism in the translational initiation codon reported to have functional significance. Although the role of rs2228570 in the risk of ovarian cancer has been widely researched, the association is still unclear. We performed an updated meta-analysis to clarify this issue.

METHODS

Eligible studies were retrieved from electronic databases for the period 2007-2016. The association was measured by unadjusted odds ratio combined with 95% confidence intervals (CIs). Random-effect or fixed-effect models were used according to the heterogeneity of the studies. We further appreciated the strength of evidence according to Venice guidance.

RESULTS

Fourteen studies (4448 cases and 7242 controls) were included in the meta-analysis. Studies were predominantly conducted in Caucasian populations (4152 cases and 6693 controls). A dominant genetic model was determined to be the most appropriate genetic model. Overall meta-analysis showed a fixed-effect odds ratio of 1.14 (95% CI 1.05-1.23) under a dominant model. The fixed-effect odds ratios were 1.12 (95% CI 1.03-1.21) and 1.49 (95% CI 1.06-2.09) in Caucasian and Asian populations, respectively. The strength of the evidence was moderate.

CONCLUSION

The rs2228570 polymorphism increased the risk of ovarian cancer in Caucasian populations in a dominant genetic model. The role of this polymorphism in the risk of ovarian cancer in Asian populations should be further studied.

Vitamin D Receptor Signaling and Cancer

The vitamin D receptor (VDR) binds the secosteroid hormone 1,25(OH)₂D₃ with high affinity and regulates gene programs that control a serum calcium levels, as well as cell proliferation and differentiation. A significant focus has been to exploit the VDR in cancer settings. Although preclinical studies have been strongly encouraging, to date clinical trials have delivered equivocal findings that have paused the clinical translation of these compounds. However, it is entirely possible that mining of genomic data will help to refine precisely what are the key anticancer actions of vitamin D compounds and where these can be used most effectively.

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.

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.

FokI Polymorphism of the Vitamin D Receptor Gene Is Associated with Susceptibility to Gastric Cancer: A Case-Control Study

Vitamin D is a potential protective agent against cancer, and its activity is mediated mainly by vitamin D receptor (VDR). The FokI polymorphism (rs10735810) represents a T-to-C transition (ATG to ACG) in exon 2 of the VDR gene, and this ATG represents the translation-initiation codon, encoded by the f allele. The FokI polymorphism results in the generation of a protein shortened by three amino acids, translated from the downstream ATG codon (the F allele). We investigated the relationship between the FokI polymorphism and gastric cancer in a Chinese Han population. A total of 187 patients and 212 healthy controls were enrolled. The FokI polymorphism was detected by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis. The f allele frequency was higher in patients than that in controls (51.6% and 43.6%, P < 0.05). Multivariate logistics regression analysis revealed patients with the f allele (Ff + ff) showed a higher risk of gastric cancer [odds ratio (95% confidence interval) 2.73 (1.13~4.32)]. Patients with the f allele (Ff + ff) also presented a poorly differentiated type of gastric cancer (P < 0.05) and higher levels of C-reactive protein on admission than the FF group (5.5 ± 2.4 mg/L vs. 3.4 ± 1.3 mg/L, P < 0.05). Here, we show an association between the VDR FokI polymorphism and the susceptibility to gastric cancer, which may be helpful for early detection of high-risk individuals with the f allele for gastric cancer. Conversely, the F allele may be a protective factor against gastric cancer.

Polymorphic variants in the vitamin D pathway genes and the risk of ovarian cancer among non-carriers of BRCA1/BRCA2 mutations

Previous studies have produced inconsistent results regarding the contribution of single-nucleotide polymorphisms (SNPs) in the vitamin D receptor (VDR) gene to ovarian cancer (OC) in various ethnicities. Additionally, little has been established with regard to the role of SNPs located in the retinoid X receptor α (RXRA), vitamin D-binding protein [also know as group-specific component (GC)] and VDR genes in non-carriers of the breast cancer 1/2 early onset (BRCA1/BRCA2) gene mutations. All participating individuals in the present study were evaluated for BRCA1 mutations (5382incC, C61G and 4153delA) with HybProbe assays, and for BRCA2 mutation (5946delT) using high-resolution melting (HRM) analysis. The associations of 8 SNPs located in RXRA, GC and VDR were investigated in OC patients without the BRCA1/BRCA2 mutations (n=245) and healthy controls (n=465). Genotyping of RXRA rs10881578 and rs10776909, and GC rs1155563 and rs2298849 SNPs was conducted by HRM analysis, while RXRA rs749759, GC rs7041, VDR BsmI rs1544410 and FokI rs2228570 genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism analysis. In addition, the gene-gene interactions among all tested SNPs were studied using the epistasis option in PLINK software. The lowest P-values of the trend test were identified for VDR rs1544410 and GC rs2298849 as P_trend=0.012 and P_trend=0.029, respectively. It was also found that, in the dominant inheritance model, VDR BsmI contributed to an increased risk of OC [odds ratio (OR), 1.570; 95% confidence interval (CI), 1.136-2.171; P=0.006; P_corr=0.048]. The gene-gene interaction analysis indicated a significant interaction between RXRA rs749759 and VDR FokI rs2228570 (OR for interaction, 1.687; χ²=8.278; asymptotic P-value=0.004; P_corr=0.032). In conclusion, this study demonstrated that certain VDR and RXRA SNPs may be risk factors for OC in non-carriers of BRCA1/BRCA2 mutations in the Polish population.

Genetic Polymorphisms Analysis of Pharmacogenomic VIP Variants in Miao Ethnic Group of Southwest China

Background

Genetic polymorphisms have a potential clinical role in determining both inter-individual and inter-ethnic differences in drug efficacy, but we have not found any pharmacogenomics information regarding minorities, such as the Miao ethnic group. Our study aimed to screen numbers of the Miao ethnic group for genotype frequencies of VIP variants and to determine differences between the Miao and other human populations worldwide.

Material/Methods

In this study, we genotyped 66 Very Important Pharmacogene (VIP) variants selected from PharmGKB in 98 unrelated, healthy Miao individuals from the Guizhou province and compared our data with 12 other populations, including 11 populations from the HapMap data set and Xi’an Han Chinese.

Results

Using the χ² test, we found that the allele frequencies of the VDR rs1544410 and VKORC1 (rs9934438) variants in the Miao population are quite different from that in other ethnic groups. Furthermore, we found that genotype frequencies of rs1801133 (MTHFR) in the 13 selected populations are significantly different. Population structure and F-statistics (Fst) analysis show that the genetic background of the Miao is relatively close to that of Chinese in metropolitan Denver, CO, USA (CHD).

Conclusions

Our results help complete the information provided by the pharmacogenomics database of the Miao ethnic group and provide a theoretical basis for safer drug administration, which may be useful for diagnosing and treating diseases in this population.

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.

Vitamin D receptor gene polymorphisms and the risk for female reproductive cancers: A meta-analysis

Vitamin D receptor (VDR) gene polymorphisms and the risks for various breast and ovarian cancers have been reported in many epidemiological studies. However, the associations between VDR gene polymorphisms and the risk for each type of cancer are unclear. The aim of this meta-analysis was to evaluate the associations between VDR gene polymorphisms and female reproductive cancers. A systematic review was performed with the PubMed Science Direct, Scopus, and Google Scholar databases up to April 2014 using the search terms "vitamin D receptor or VDR" and "variant or polymorphism or SNP" with terms for breast, ovarian, cervical, endometrial, uterine, and vaginal cancers. A meta-analysis with the pooled odds ratios and 95% confidence intervals was carried out to assess the associations between VDR polymorphisms (Cdx-2, FokI, BsmI, ApaI, and TaqI) and the risks for reproductive cancers under the heterozygous, homozygous, dominant, and recessive models with fixed or random effects models. Six ovarian cancer studies (13 individual studies involving 4107 cases and 6661 controls) and 29 breast cancer studies (38 individual studies involving 16,453 cases and 22,044 controls) were included in our meta-analysis. Our results indicate that the FokI polymorphism was related to increased risks for breast and ovarian cancers, whereas the BsmI polymorphism was associated with a decreased risk for developing these cancers. Our comprehensive meta-analysis indicated that the FokI and BsmI VDR gene polymorphisms may be significantly associated with gynecological cancers. We suggest monitoring VDR gene polymorphisms as potential biomarkers in patients with gynecological malignancy.

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.

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.

Vitamin D receptor FokI, BsmI, ApaI, and TaqI polymorphisms and susceptibility to ovarian cancer: a meta-analysis

OBJECTIVE

The goal of this study was to explore whether vitamin D receptor (VDR) polymorphisms are associated with susceptibility to ovarian cancer.

METHODS

Meta-analyses were conducted on the associations between the VDR FokI, BsmI, ApaI, and TaqI polymorphisms and ovarian cancer.

RESULTS

A total of 12 comparison studies were considered in the meta-analysis, which involved 3716 patients and 5059 controls. Meta-analysis of the VDR FokI polymorphism showed an association between ovarian cancer and the f allele in European populations (OR = 1.094, 95% CI = 1.028-1.163, p = 0.004). Meta-analysis revealed an association between ovarian cancer and the ApaI A allele in all study subjects and Europeans as a sub-group (OR = 1.235, 95% CI = 1.019-1.497, p = 0.032 and OR = 1.287, 95% CI = 1.029-1.609, p = 0.027, respectively). No association was found between ovarian cancer and the BsmI and Taq polymorphisms (OR for B allele = 1.084, 95% CI = 0.936-1.255, p = 0.280, OR for the T allele = OR = 0.847, 95% CI = 0.706-1.270, p = 0.716).

CONCLUSIONS

This meta-analysis suggests that the VDR FokI and ApaI polymorphisms are associated with susceptibility to ovarian cancer in European populations.

The VDR gene FokI polymorphism and ovarian cancer risk

The polymorphism of vitamin D receptor (VDR) gene is demonstrated to affect the activity of its encoding protein and the subsequent downstream effects mediated by vitamin D. Mutations in VDR gene FokI have been suggested in the development of various cancers. Whether the polymorphism of the VDR gene FokI confers risk to ovarian cancer still remains controversial across the published studies in different ethnicity. The aim of this meta-analysis was to determine the role of VDR gene FokI variant in the susceptibility to ovarian cancer. Six publications with 14 individual case-control studies involving a total of 10,964 subjects were finally included into our study after a comprehensive literature search of the PubMed, Embase, Web of Science, and Wanfang databases. The strength of the association between the VDR gene FokI polymorphism and ovarian cancer risk was estimated under the allelic (T vs. C), homozygous (TT vs. CC), additive (CT vs. CC), recessive (TT vs. CC + CT), and dominant (CT + TT vs. CC) gene models. The overall odds ratios (ORs) for the contrast models of T vs. C, TT vs. CC, CT vs. CC, and CT + TT vs. CC indicated that the VDR gene FokI variant was related to an increased risk of ovarian cancer (OR(T vs. C) = 1.09, 95 % confidence interval (CI) 1.03-1.15, P(OR) = 0.004; OR(TT vs. CC) = 1.17, 95 % CI 1.04-1.32, P(OR) = 0.011; OR(CT vs. CC) = 1.10, 95 % CI 1.01-1.20, P(OR) = 0.027; OR(CT + TT vs. CC) = 1.12, 95 % CI 1.03-1.21, P(OR) = 0.007). The stratified analysis among the Caucasians also identified a significant association between the VDR gene FokI polymorphism and the susceptibility to ovarian cancer. The present meta-analysis with large available published data has revealed that the VDR gene FokI polymorphism confers susceptibility to ovarian cancer, particularly among the Caucasian population.

Polymorphisms of MUC16 (CA125) and MUC1 (CA15.3) in relation to ovarian cancer risk and survival

Objective

To examine single nucleotide polymorphism (SNPs) in MUC16 (CA125) and MUC1 (CA15.3) in relation to ovarian cancer risk and survival.

Methods

We genotyped germline variants of MUC16 (rs2547065, rs1559168, rs12984471, rs2121133) and MUC1 (rs2070803, rs4072037, rs1045253) using samples collected from 758 ovarian cancer cases and 788 controls enrolled in the New England Case-Control Study between 2003 and 2008. We calculated age-adjusted odds ratios (OR) and 95% confidence intervals (CIs) for disease risk using unconditional and polytomous logistic regression and hazard ratios (HR) for survival using Cox proportional hazard ratios. In a subset of cases, we compared log-normalized CA125 values by genotype using generalized linear models.

Results

Cases homozygous for the variant allele of MUC16 SNP, rs12984471, had poorer overall survival (log-rank p = 0.03) and higher CA125 levels, especially cases over age 65 (p = 0.01). For MUC1 SNP, rs4072037, women homozygous for the G variant had a non-significantly decreased risk for serous invasive types but elevated risk for serous borderline tumors, mucinous borderline and invasive tumors, and endometrioid tumors. Women with the variant allele of MUC16 SNP, rs2547065, especially those who were homozygous had an elevated risk for ovarian cancer; but this association was not confirmed in an independent dataset.

Conclusion

This targeted screen of seven polymorphisms of MUC16 and MUC1 genes failed to identify and confirm effects on ovarian cancer risk overall. However, there may be effects of MUC16 rs12984471 on survival and MUC1 rs4072037 on risk for histologic types of ovarian cancer other than invasive serous. Further study is warranted.

Systematic review and meta-analysis on vitamin D receptor polymorphisms and cancer risk

The vitamin D receptor (VDR) can influence cancer susceptibility through binding to vitamin D. However, the previous studies were contradictory. Therefore this meta-analysis was conducted to clarify the association between VDR polymorphisms (BsmI, TaqI, FokI, and ApaI) and cancer risk. One hundred twenty-six studies were enrolled through PubMed. For VDR BsmI polymorphism, significantly increased cancer risks were observed in the overall analysis. In the further stratified analysis, increased risks were observed in colorectal and skin cancer, especially in Caucasian population. However, no significant associations were observed in other VDR polymorphisms in the overall analysis. In the further subgroup analysis, increased risks were found in oral, breast, and basal cell cancer while decreased risk was found in prostate cancer in t allele carriers of TaqI polymorphism. For VDR FokI polymorphism, increased risks were found in ovarian and skin cancer while decreased risk in glioma in f allele carriers. For VDR ApaI polymorphism, increased risk was observed in basal cell cancer, especially in Asian population in a allele carriers. In conclusion, these results indicated that b allele of BamI polymorphism was a risk factor for cancer susceptibility. Meanwhile, t allele of TaqI polymorphism was a risk factor for oral, breast, and basal cell cancer and a protective factor for prostate cancer. Moreover, f allele of FokI polymorphism was a risk factor for ovarian and skin cancer and a protective factor for glioma. Finally, a allele of ApaI polymorphism was a risk factor for basal cell cancer in Asian population.

Systematic review and meta-analysis on vitamin D receptor polymorphisms and cancer risk

The vitamin D receptor (VDR) can influence cancer susceptibility through binding to vitamin D. However, the previous studies were contradictory. Therefore this meta-analysis was conducted to clarify the association between VDR polymorphisms (BsmI, TaqI, FokI, and ApaI) and cancer risk. One hundred twenty-six studies were enrolled through PubMed. For VDR BsmI polymorphism, significantly increased cancer risks were observed in the overall analysis. In the further stratified analysis, increased risks were observed in colorectal and skin cancer, especially in Caucasian population. However, no significant associations were observed in other VDR polymorphisms in the overall analysis. In the further subgroup analysis, increased risks were found in oral, breast, and basal cell cancer while decreased risk was found in prostate cancer in t allele carriers of TaqI polymorphism. For VDR FokI polymorphism, increased risks were found in ovarian and skin cancer while decreased risk in glioma in f allele carriers. For VDR ApaI polymorphism, increased risk was observed in basal cell cancer, especially in Asian population in a allele carriers. In conclusion, these results indicated that b allele of BamI polymorphism was a risk factor for cancer susceptibility. Meanwhile, t allele of TaqI polymorphism was a risk factor for oral, breast, and basal cell cancer and a protective factor for prostate cancer. Moreover, f allele of FokI polymorphism was a risk factor for ovarian and skin cancer and a protective factor for glioma. Finally, a allele of ApaI polymorphism was a risk factor for basal cell cancer in Asian population.

Vitamin D Receptor BsmІ Polymorphism and Ovarian Cancer Risk: A Meta-Analysis

Objective

Vitamin D receptor (VDR) FokI polymorphism has been reported to influence ovarian cancer (OC) susceptibility, but the association between VDR BsmI polymorphism and OC risk remains controversial. To clarify the relationship between them, we performed a meta-analysis.

Methods

A comprehensive literature search was conducted to examine all the eligible studies of VDR BsmI polymorphism and OC risk. Odds ratios (OR) with 95% confidence intervals (95% CI) were used to assess the strength of this association.

Results

Seven separate comparisons consisting of 1977 OC cases and 2832 healthy controls were included in our meta-analysis. The pooled analyses showed no significant association between VDR BsmI G/A polymorphism and OC in all of the comparisons (AA vs GG: OR, 1.01; P = 0.919; AG vs GG: OR, 1.12; P = 0.087; AG + AA vs GG: OR, 1.10; P = 0.146; AA vs AG + GG: OR, 0.96; P = 0.629). However, subgroup analysis showed a significant contribution of the dominant inheritance model to OC development in the European group: AG + AA vs GG (OR, 1.43; P = 0.029); AG vs GG (OR, 1.46; P = 0.031).

Conclusions

Vitamin D receptor BsmI G/A gene variant might be a moderate risk factor of OC development in the European population instead of North America or Asian population.

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.

Vitamin D and VDR gene polymorphism (FokI) in epithelial ovarian cancer in Indian population

Introduction

Vitamin D deficiency and vitamin D receptor (VDR) gene polymorphism, FokI, is reported to increase the risk of many cancers. Role of vitamin D and its receptor polymorphisms in ovarian cancer has not been clearly defined.

Objective

To study the levels of serum vitamin D and occurrence of vitamin D receptor gene polymorphism (FokI) in cases of ovarian cancer.

Material and methods

FokI genotyping was done by PCR-RFLP technique and vitamin D levels were estimated by chemiluminescence immunoassay.

Results

Serum vitamin D levels were significantly (p < 0.03) lower in ovarian cancer cases as compared to controls. The homozygous (TT) and heterozygous (CT) genotype predispose to the development of ovarian cancer in Indian population (OR: 2.37, 95% CI: 1.04-5.44) as compared to the homozygous (CC) genotype. Vitamin D deficiency and VDR gene polymorphism (FokI) act non-synergistically (p value < 0.4).

Conclusion

Low blood levels of vitamin D and VDR receptor polymorphism (FokI) might be a risk factor for the development of ovarian cancer. Other novel ligands of vitamin D receptor might be responsible for the non-synergistic effect.

Vitamin D receptor gene BsmI and FokI polymorphisms in relation to ovarian cancer risk in the Polish population

BACKGROUND

The role of vitamin D receptor (VDR) single-nucleotide polymorphisms (SNPs) in ovarian cancer has been studied in various populations; however, these results are discordant between different ethnicities.

METHOD

Using the polymerase chain reaction-restriction fragment length polymorphism method, we studied the prevalence of the VDR FokI (rs2228570) and BsmI (rs1544410) SNPs in women with ovarian cancer (n=168) and controls (n=182) in a Polish population.

RESULTS

We found a significant contribution of the BsmI SNP Bb+BB-versus-bb dominant inheritance model to ovarian cancer development (p=0.0221, p(corr)=0.0442, odds ratio [OR]=1.648 [95% confidence intervals, CI=1.073-2.532]). However, we did not observe an association of the BsmI SNP BB versus Bb+bb recessive inheritance model in patients (p=0.8059, OR=1.093 [95% CI=0.538-2.218]). Moreover, there was no association of FokI SNPs either in Ff+ff versus FF dominant or ff versus Ff+FF recessive inheritance models with ovarian cancer development (p=0.9924, OR=1.002 [95% CI=0.628-1.599] and p=0.1123, OR=1.542 [95% CI=0.901-2.638], respectively). The p-values of the trend test observed for the VDR BsmI and FokI SNPs in patients with ovarian cancer were p(trend)=0.0613 and p(trend)=0.3655, respectively.

CONCLUSION

Our study indicates that the VDR B gene variant might be a moderate risk factor of ovarian cancer development in the Polish population.

Vitamin D receptor (VDR) polymorphisms and risk of ovarian cancer in Caucasian and African American women

OBJECTIVE

Polymorphisms in the vitamin D receptor (VDR) gene have been shown in some studies to be associated with the risk of epithelial ovarian cancer (EOC) in Caucasian women. There are no published reports among African Americans.

METHODS

Case-control data from the North Carolina Ovarian Cancer Study were analyzed using logistic regression to determine the association between seven VDR polymorphisms and EOC in both Caucasians (513 cases, 532 controls) and African Americans (74 cases, 79 controls). In a larger sample of African-Americans (125 cases, 155 controls), we assessed associations between six SNPs in proximity of rs7975232.

RESULTS

African American women who carried at least one minor allele of rs7975232 were at higher risk for invasive EOC controlling for age and admixture with an odds ratio (OR) for association under the log-additive model of 2.08 (95% confidence interval (CI)=1.19, 3.63, p=0.010). No association was observed between any of the VDR variants and EOC among Caucasians. A larger sample of African Americans revealed a nearly two-fold increased risk of invasive EOC associated with rs7305032, a SNP in proximity to rs7975232 (R(2)=0.369) with a log-additive OR of 1.87 (95% CI=1.20, 2.93, p=0.006).

CONCLUSIONS

This is the first report showing VDR variants associated with ovarian cancer risk in African American women. A larger study of African American women is needed to confirm these findings. These results imply that vitamin D exposure is a possible modifiable risk factor of ovarian cancer among African Americans.

Polymorphisms in the p63 and p73 genes are associated with ovarian cancer risk and clinicopathological variables

Objective

p73 and p63 are two structural and functional homologs of p53, and their biological functions in cancer progression have attracted attention due to the presence of variants generated by genetic polymorphisms. Recently, three single nucleotide polymorphisms (SNPs) in the p63 and p73 genes have been associated with female reproduction. In the present study, we aimed to evaluate the relationship between these SNPs and ovarian cancer susceptibility and clinical pathology.

Methods

We genotyped the p63 (rs873330 [Genbank, refSNP ID] T > C [T: original base, C: mutant base]) and p73 (rs4648551 G > A and rs6695978 G > A) SNPs in ovarian cancers and healthy controls and analyzed the distributions of genotype frequencies to evaluate the association of the genotypes with the risk of ovarian cancer and the clinicopathological characteristics. Logistic regression models were applied in statistical analyses.

Results

Our research revealed that p73 rs6695978 G > A was significantly associated with ovarian cancer patients. Women with the A allele were at increased risk of ovarian cancer compared to carriers of the G allele (OR = 1.55; 95% CI:1.07–2.19; P = 0.003). Meanwhile, the at-risk A allele was positively related with the occurrence of mucinous ovarian cancer (OR = 3.48; 95% CI:1.15-6.83; P = 0.001), low degree of differentiation (OR = 1.87; 95% CI:1.03-3.47; P = 0.003), lymph node metastasis (OR = 1.69; 95% CI: 1.14-2.75; P = 0.010) and estrogen receptor positive (OR = 2.72; 95% CI: 1.38-4.81; P = 0.002). However, we were unable to find any associations of the polymorphisms in another two SNPs (rs4648551 G > A, rs873330 T > C) with ovarian cancer risk and clinicopathological parameters.

Conclusions

The p73 rs6695978 G > A polymorphism will serve as a modifier of ovarian cancer susceptibility and prognosis. Further investigations with large sample sizes and of the mechanistic relevance of p73 polymorphism will be warranted

Sun exposure and risk of epithelial ovarian cancer

PURPOSE

Associations between sun exposure (a primary source of vitamin D) and risk of ovarian cancer have been inconsistent. Furthermore, studies have not investigated whether sun exposure at different periods in the lifetime of a person results in differences in risk associations, and little is known about differences according to histological subtype.

METHODS

Using a population-based case-control study of 1,334 non-Hispanic white women diagnosed with epithelial ovarian cancer in western Washington State between 2002 and 2009 and 1,679 non-Hispanic white controls, we assessed the relation of epithelial ovarian cancer with constitutional pigmentation characteristics, sun exposure behaviors, and an index of ultraviolet (UV) exposure based on residential history. Information was collected through in-person interviews. Logistic regression was used to compute odds ratios, 95 % confidence intervals, and trend p values (P(trend)).

RESULTS

We noted no association with residence-based measures of UV exposure or self-reported sun exposure, either over the lifetime or within specific age intervals. Also, we observed little evidence of association between constitutional pigmentation characteristics and risk, save for a suggestion of increased risk among women who reported increased ability to suntan upon prolonged sun exposure (P(trend) = 0.03).

CONCLUSIONS

Results from this study suggest that sun exposure has little influence on the risk of epithelial ovarian cancer. Additional studies in populations with a wider gradient of sun exposure may yet be warranted.

25(OH)D3 in patients with ovarian cancer and its correlation with survival

OBJECTIVES

The aim of this study was to examine vitamin 25(OH)D3 concentration in ovarian cancer patients in relation to a pathological subtype of the tumor, FIGO stage, grading, menopause status and overall 5-year survival.

DESIGN AND METHODS

72 epithelial ovarian cancer patients aged 37-79, who undergone optimal cytoreductive surgery were enrolled to the study group. Serum 25(OH)D3 concentration was measured using an electrochemiluminescence immunoassay before surgery. Serum concentration of 25(OH)D3 was also measured in a group of 65 healthy non-obese women aged 35-65 years.

RESULTS

In patients with ovarian cancer serum concentration of 25(OH)D3 was lower than in the reference group (12.5±7.75 ng/mL vs 22.4±6.5 ng/mL). No significant correlation was found between serum 25(OH)D3 concentration and histological subtype, grading, FIGO stage and menopausal status. The study group was divided into two subgroups and the survival curves were analyzed. Overall 5-year survival rate was significantly higher in the subgroup of patients with 25(OH)D3 concentration over 10 ng/mL compared to women with concentration below 10 ng/mL.

CONCLUSIONS

Low 25(OH) D3 concentration associated with lower overall survival rate might suggest for the important role of severe deficiency in more aggressive course of ovarian cancer. Testing for 25(OH)D in the standard procedure could help to find ovarian cancer patients with worse prognosis, who would benefit of special attention and supplementation.

Dairy foods and nutrients in relation to risk of ovarian cancer and major histological subtypes

Inconsistent results for the role of dairy food intake in relation to ovarian cancer risk may reflect the potential adverse effects of lactose, which has been hypothesized to increase gonadotropin levels, and the beneficial antiproliferative effects of calcium and vitamin D. Using data from the New England case-control study (1,909 cases and 1,989 controls), we examined dairy foods and nutrients in relation to risk of ovarian cancer overall, histological subtypes and rapidly fatal versus less aggressive disease. We used logistic regression and polytomous logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs). In models that were simultaneously adjusted for total (dietary plus supplements) calcium, total vitamin D and lactose, we observed a decreased overall risk of ovarian cancer with high intake of total calcium [Quartile 4 (Q4, >1,319 mg/day) vs. Quartile 1 (Q1, <655 mg/day), OR = 0.62, 95% CI = 0.49-0.79]; the inverse association was strongest for serous borderline and mucinous tumors. High intake of total vitamin D was not associated overall with ovarian cancer risk, but was inversely associated with risk of serous borderline (Q4, >559 IU/day vs. Q1, <164 IU/day, OR = 0.51, 95% CI = 0.34-0.76) and endometrioid tumors (Q4 vs. Q1, OR = 0.55, 95% CI = 0.39-0.80). We found no evidence that lactose intake influenced ovarian cancer risk or that risk varied by tumor aggressiveness in the analyses of intake of dairy foods and nutrients. The overall inverse association with high intake of calcium and the inverse associations of calcium and vitamin D with specific histological subtypes warrant further investigation.

The independent association between 25-hydroxyvitamin D and adiponectin and its relation with BMI in two large cohorts: the NHS and the HPFS

Low 25-hydroxyvitamin D (25(OH)D) and adiponectin levels are both associated with obesity and cardiovascular disease. Cross-sectional studies have suggested that 25(OH)D concentrations are positively associated with adiponectin, and that this relation may strengthen with increasing BMI. However, these studies had small samples sizes and did not account for many known confounders of adiponectin levels. We evaluated whether 25(OH)D was independently associated with circulating adiponectin in two large populations, and whether BMI modified this relationship. Cross-sectional analyses were performed on 1,206 women from the Nurses' Health Study I (NHS) and 439 men from the Health Professionals Follow-Up Study. Multivariable linear regression was used to analyze the independent association between 25(OH)D and adiponectin after controlling for potential confounders. Effect modification by BMI was examined by creating interaction terms between vitamin D and BMI. 25(OH)D concentrations were positively associated with circulating adiponectin in univariate analyses, and also independently associated with adiponectin after multivariable adjustments in both populations (women: β = 0.06, P < 0.001; men: β = 0.07, P < 0.05). BMI did not significantly modify the relation between 25(OH)D and adiponectin in either population. Higher 25(OH)D concentrations were independently associated with higher adiponectin concentrations in large populations of women and men. Since lower levels of 25(OH)D and adiponectin are associated with higher cardio-metabolic risk, assessing the effect of vitamin D supplementation on adiponectin levels is warranted.

Meta-analysis: Circulating vitamin D and ovarian cancer risk

OBJECTIVE

To review and summarize evidence from longitudinal studies on the association between circulating 25 hydroxyvitamin D (25(OH)D) and the risk of ovarian cancer (OC).

METHODS

Relevant prospective cohort studies and nested case-control studies were identified by systematically searching Ovid Medline, EMBASE, and ISI Web of Knowledge databases and by cross-referencing. The following data were extracted in a standardized manner from eligible studies: first author, publication year, country, study design, characteristics of the study population, duration of follow-up, OC incidence according to circulating vitamin D status and the respective relative risks, and covariates adjusted for in the analysis. Due to the heterogeneity of studies in categorizing circulating vitamin D levels, all results were recalculated for an increase of circulating 25(OH)D by 20ng/ml. Summary relative risks (RRs) were calculated using meta-analysis methods.

RESULTS

Overall, ten individual-level studies were included that reported on the association between circulating vitamin D levels and OC incidence. Meta-analysis of studies on OC incidence resulted in a summary RR (95% confidence interval, CI) of 0.83 (0.63-1.08) for an increase of 25(OH)D by 20ng/ml (P=0.160). No indication for heterogeneity and publication bias was found.

CONCLUSIONS

A tentative inverse association of circulating 25(OH)D with OC incidence was found, which did not reach statistical significance but which requires clarification by additional studies due to potentially high clinical and public health impact.

Vitamin D receptor rs2228570 polymorphism and invasive ovarian carcinoma risk: pooled analysis in five studies within the Ovarian Cancer Association Consortium

The association of invasive ovarian carcinoma risk with the functional polymorphism rs2228570 (aka rs10735810; FokI polymorphism) in the vitamin D receptor (VDR) gene was examined in 1820 white non-Hispanic cases and 3479 controls in a pooled analysis of five population-based case-control studies within the Ovarian Cancer Association Consortium. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using unconditional logistic regression. Carriers of the rare T allele were at increased risk of ovarian carcinoma compared to women with the CC genotype in all studies combined; each copy of the T allele was associated with a modest 9% increased risk (OR = 1.09; 95% CI: 1.01-1.19; p = 0.04). No significant heterogeneity among studies was observed (p = 0.37) and, after excluding the dataset from the Hawaii study, the risk association for rs2228570 among replication studies was unchanged (OR = 1.09; 95% CI: 1.00-1.19; p = 0.06). A stronger association of rs2228570 with risk was observed among younger women (aged < 50 years versus 50 years or older) (p = 0.04). In all studies combined, the increased risk per copy of the T allele among younger women was 24% (OR = 1.24; 95% CI: 1.04-1.47; p = 0.02). This association remained statistically significant after excluding the Hawaii data (OR = 1.20; 95% CI: 1.01-1.43; p = 0.04). No heterogeneity of the association was observed by stage (p = 0.46), tumor histology (p = 0.98), or time between diagnosis and interview (p = 0.94). This pooled analysis provides further evidence that the VDR rs2228570 polymorphism might influence ovarian cancer susceptibility.

Thyroid cancer resistance to vitamin D receptor activation is associated with 24-hydroxylase levels but not the ff FokI polymorphism

BACKGROUND

The vitamin D receptor (VDR) has been studied as a novel target for cancer therapy in many tissue types as VDR ligands decrease cell proliferation in vitro and decrease tumor growth in vivo in sensitive cells. The objective of this study was to analyze the response to VDR agonist therapy in a panel of validated thyroid cancer cells and assess genetic markers predicting sensitivity and resistance to calcitriol and the noncalcemic analog DP006.

METHODS

Thyroid cancer cell lines were analyzed for VDR and RXR protein by Western blot. Cell growth after VDR agonist treatment (calcitriol or DP006) was assessed after 6 days of treatment by viable cell assay. To investigate calcitriol/DP006 resistance in VDR-expressing cells, the VDR was sequenced and 1-α and 24-hydroxylase mRNA expression was assessed.

RESULTS

VDR protein was variably expressed in the thyroid cancer cell lines and its presence was not sufficient for decreased viable cell count in response to calcitriol or DP006. The most sensitive cells (TPC1) have an ff FokI VDR polymorphism and the most resistant cells (HTh7 and 8505C) have an FF FokI VDR. This is a unique finding given that the balance of the literature of VDR polymorphisms describes an association of the ff FokI polymorphism with cancer risk and/or decreased VDR transactivation. 1-α and 24-hydroxylase mRNA expression before and after VDR agonist therapy was examined. 1-α-Hydroxylase levels did not change after calcitriol treatment. However, we found that higher baseline 24-hydroxylase levels and/or lower stimulation of 24-hydroxylase levels after calcitriol treatment were associated with relative resistance to calcitriol/DP006.

CONCLUSIONS

The VDR represents a novel therapeutic target in poorly differentiated thyroid cancer; however, the efficacy of VDR agonist therapy to decrease viable thyroid cancer cell count cannot be predicted solely on the presence of the VDR. The FF FokI VDR genotype and high baseline 24-hydroxylase levels were associated with relative resistance to calcitriol and DP006. Therefore, identifiable markers of sensitivity or resistance to VDR agonist therapy may allow for a personalized use of these agents in poorly differentiated thyroid cancer.

Circulating 25-hydroxyvitamin D and risk of epithelial ovarian cancer: Cohort Consortium Vitamin D Pooling Project of Rarer Cancers

A role for vitamin D in ovarian cancer etiology is supported by ecologic studies of sunlight exposure, experimental mechanism studies, and some studies of dietary vitamin D intake and genetic polymorphisms in the vitamin D receptor. However, few studies have examined the association of circulating 25-hydroxyvitamin D (25(OH)D), an integrated measure of vitamin D status, with ovarian cancer risk. A nested case-control study was conducted among 7 prospective studies to evaluate the circulating 25(OH)D concentration in relation to epithelial ovarian cancer risk. Logistic regression models were used to estimate odds ratios and 95% confidence intervals among 516 cases and 770 matched controls. Compared with 25(OH)D concentrations of 50–<75 nmol/L, no statistically significant associations were observed for <37.5 (odds ratio (OR) = 1.21, 95% confidence interval (CI): 0.87, 1.70), 37.5–<50 (OR = 1.03, 95% CI: 0.75, 1.41), or ≥75 (OR = 1.11, 95% CI: 0.79, 1.55) nmol/L. Analyses stratified by tumor subtype, age, body mass index, and other variables were generally null but suggested an inverse association between 25(OH)D and ovarian cancer risk among women with a body mass index of ≥25 kg/m² (P_interaction < 0.01). In conclusion, this large pooled analysis did not support an overall association between circulating 25(OH)D and ovarian cancer risk, except possibly among overweight women.