Genetic variation in vitamin D-related genes and risk of breast cancer among women of European and East Asian descent

Pathology-supported genetic testing for the application of breast cancer pharmacodiagnostics: family counselling, lifestyle adjustments and change of medication

BACKGROUND

Pathology-supported genetic testing (PSGT) enables transitioning of risk stratification from the study population to the individual.

RESEARCH DESIGN AND METHODS

We provide an overview of the translational research performed in postmenopausal breast cancer patients at increased risk of osteoporosis due to aromatase inhibitor therapy, as the indication for referral. Both tumour histopathology and blood biochemistry levels were assessed to identify actionable disease pathways using whole exome sequencing (WES).

RESULTS

The causes and consequences of inadequate vitamin D levels as a modifiable risk factor for bone loss were highlighted in 116 patients with hormone receptor-positive breast cancer. Comparison of lifestyle factors and WES data between cases with vitamin D levels at extreme upper and lower ranges identified obesity as a major discriminating factor, with the lowest levels recorded during winter. Functional polymorphisms in the vitamin D receptor gene contributed independently to therapy-related osteoporosis risk. In a patient with invasive lobular carcinoma, genetic counselling facilitated investigation of the potential modifying effect of a rare CDH1 variant co-occurring withBRCA1 c.66dup (p.Glu23ArgfsTer18).

CONCLUSION

Validation of PSGT as a three-pronged pharmacodiagnostics tool for generation of adaptive reports and data reinterpretation during follow-up represents a new paradigm in personalised medicine, exposing significant limitations to overcome.

Vitamin D receptor gene polymorphisms and risk of breast cancer in Iranian women

OBJECTIVES

Vitamin D deficiency is a driving force of common cancers like breast cancer. Vitamin D receptor (VDR) can play a tumor suppressor role by helping the precise function of vitamin D in cells such as modulation TGF-β signaling pathway. This study aimed to investigate the association of VDR gene variants and susceptibility to breast cancer in Iranian women.

METHODS

Genomic DNAs were isolated from blood samples of 161 women with breast cancer and 150 healthy women. After amplification of five positions of VDR gene, the prepared amplicons were digested with TaqI, ApaI, BsmI, Cdx2, and FokI restriction enzymes.

RESULTS

Subsequently, the digested products were electrophoresed on the 1.5% agarose gel. Odds ratios (ORs) for breast cancer were calculated for genotypes and estimated haplotypes. Binary logistic regression analysis showed FokI (rs2228570), BsmI (rs1544410), and ApaI (rs7975232) polymorphisms had the significant distribution in patients than to the normal group. Analysis of linkage disequilibrium for all pairs of SNPs showed that D'-value between SNP TaqI and SNP BsmI was significantly (p ≤ 0.05). We observed that four major haplotypes of ApaI, BsmI, FokI, Cdx2, and TaqI SNPs significantly were in high frequency than predicted frequency. Among these four haplotypes, CGTAT haplotype was in a higher significant association than others with breast cancer risk (p-value = 0.0001).

CONCLUSION

Our results showed that FokI, BsmI, and ApaI of VDR polymorphisms associated with the risk of breast cancer in Iranian population.

Role of vitamin D3 in selected malignant neoplasms

Vitamin D₃ is a fat-soluble essential nutrient that affects multiple biologic functions in the organism through calcitriol and the vitamin D₃ receptor. This review article focuses on the results of studies on the relationship between the level of vitamin D₃ and cancer incidence or mortality, but also on the anticancer properties of vitamin D₃ that support its significant role in the prevention, clinical course, and overall survival rates of selected cancers (colorectal, prostate, breast, ovarian, endometrial, bladder, and malignant melanoma). The mechanisms of vitamin D₃ action involve, among others, polymorphism of vitamin D₃ receptor, cell cycle, caspases, and cancer stem cells. The level of vitamin D₃ has been also demonstrated to serve as a biomarker in some cancers, and high levels of vitamin D₃ can be conducive to successful cancer therapy.

Genetic polymorphisms in vitamin D pathway influence 25(OH)D levels and are associated with atopy and asthma

Background

Vitamin D deficiency or insufficiency, has been associated with atopy and lack of asthma control. Our objective was to investigate associations between variants in genes of vitamin D pathway with serum levels of 25-hydroxyvitamin D (25(OH)D), atopy, asthma and asthma severity in teenagers from Northeast Brazil.

Methods

This is a cross sectional study nested in a cohort population of asthma. 25(OH)D was quantified from 968 of 11–17 years old individuals by ELISA. Asthma diagnosis was obtained by using the ISAAC Phase III questionnaire. Specific IgE was determined by ImmunoCAP; genotyping was performed using the 2.5 HumanOmni Biochip from Illumina. Statistical analyses were performed in PLINK 1.07 and SPSS 22.1.

Results

After quality control, 104 Single Nucleotides Variants (SNVs) in vitamin D pathway genes, typed in 792 individuals, were included in the analysis. The allele A of rs10875694 on VDR was positively associated with atopy (OR = 1.35; 95% CI 1.01–1.81). The allele C of rs9279 on VDR, was negatively associated with asthma risk (OR = 0.66; 95% CI 0.45–0.97), vitamin D insufficiency (OR = 0.78; 95% CI 0.70–0.96) and higher VDR expression. Two variants in VDR were associated with asthma severity, the allele A of rs2189480 (OR = 0.34; 95% CI 0.13–0.89) and the allele G of rs4328262 (OR = 3.18; 95% CI 1.09–9.28). The combination of variants in CYP2R1 and CYP24A1 (GAC, to rs10500804, rs12794714 and rs3886163, respectively) was negatively associated with vitamin D production (β = − 1.24; 95% CI − 2.42 to − 0.06).

Conclusions

Genetic variants in the vitamin D pathway affect vitamin D serum levels and, thus, atopy and asthma.

Vitamin D intake, blood vitamin D levels, and the risk of breast cancer: a dose-response meta-analysis of observational studies

Epidemiological studies have indicated that blood vitamin D levels are linked to cancer. Here we conducted a dose-response meta-analysis based on published observational studies to evaluate the association of vitamin D intake and blood vitamin D levels with breast cancer susceptibility. PubMed, EMBASE, and Web of Science databases were searched up to January 2019. The pooled odds ratio (OR) and 95% confidence intervals (CIs) were extracted to estimate the risk. We identified 70 relevant studies on blood vitamin D levels (50 studies) and vitamin D intake (20 studies), respectively. Linear and nonlinear trend analyses were performed and showed that an increase in blood vitamin D levels by 5 nmol/l was associated with a 6% decrease in breast cancer risk (OR = 0.94, 95% CI = 0.93-0.96). Similar results were obtained for premenopausal (OR = 0.96, 95% CI = 0.93-0.99) and postmenopausal women (OR = 0.96, 95% CI = 0.94-0.98). The pooled OR of breast cancer risk for a 400IU/day increase in vitamin D intake was 0.97 (95% CI = 0.92-1.02). In conclusion, we found that breast cancer risk was inversely related to blood vitamin D levels; however, no significant association was observed in vitamin D intake.

Genetic variants in genes related to inflammation, apoptosis and autophagy in breast cancer risk

BACKGROUND

Inflammation contributes to breast cancer development through its effects on cell damage. This damage is usually dealt with by key genes involved in apoptosis and autophagy pathways.

METHODS

We tested 206 single nucleotide polymorphisms (SNPs) in 54 genes related to inflammation, apoptosis and autophagy in a population-based breast cancer study of women of European (658 cases and 795 controls) and East Asian (262 cases and 127 controls) descent. Logistic regression was used to estimate odds ratios for breast cancer risk, and case-only analysis to compare breast cancer subtypes (defined by ER/PR/HER2 status), with adjustment for confounders. We assessed statistical interactions between the SNPs and lifestyle factors (smoking status, physical activity and body mass index).

RESULTS AND CONCLUSION

Although no SNP was associated with breast cancer risk among women of European descent, we found evidence for an association among East Asians for rs1800925 (IL-13) and breast cancer risk (OR = 2.08; 95% CI: 1.32-3.28; p = 0.000779), which remained statistically significant after multiple testing correction (padj = 0.0350). This association was replicated in a meta-analysis of 4305 cases and 4194 controls in the Shanghai Breast Cancer Genetics Study (OR 1.12, 95% CI: 1.03-1.21, p = 0.011). Further, we found evidence of an interaction between rs7874234 (TSC1) and physical activity among women of East Asian descent.

Serum vitamin D level, sun-exposed area, dietary factors, and physical activity as predictors of invasive breast cancer risk among Sudanese women: A case-control study

Background:

The role of vitamin D in the development, progression, and prognosis of breast cancer, though widely studied worldwide, has been inconclusive. This study intended to assess the role of some factors (including serum vitamin D level, sun-exposed area, dietary factors, and physical activity) as predictors of the development of invasive breast cancer (IBC) among Sudanese women.

Methods:

A case–control study was conducted on 200 Sudanese women (100 with newly diagnosed IBC and 100 matched healthy females). Serum 25-hydroxyvitamin D was measured through a competitive electrochemiluminescence immunoassay. Matching analysis was adopted by R version 3.4.1 making use of the “MatchIt” package for calculating propensity scores to build a confounder-adjusted, multiple generalized, linear logistic regression model.

Results:

Participants’ age ranged from 28 to 85 years with a mean [±standard deviation (SD)] of 48.10 (±12.11) years. The mean (±SD) serum vitamin D level was 12.97 (±8.60) and 13.79 (±6.79) ng/mL in breast cancer and noncancer Sudanese women, respectively [P = 0.013; odds ratio (OR) 0.862; 95% confidence interval (CI) 0.766–0.969; β = 0.149)]. Sun-exposed area (P = 0.038; OR 0.013; 95% CI 0.000–0.782; β = 4.339) is significantly and negatively associated with breast cancer development. While moderate physical activity (P = 0.0008; OR 2625.430; 95% CI 26.647–258673.001; β = 7.873) is significantly and positively associated with IBC risk. Occasional consumption of milk, dairy products, eggs, and fish reduces the risk of developing IBC by 78.1%, 75.0%, 78.4%, and 76.4%, respectively.

Conclusion:

The higher the plasma vitamin D level by one unit, the lower the risk of breast cancer by 13.84%. Sedentary lifestyle, reduced sun-exposed skin area, and low serum vitamin D levels can be considered as predictors of IBC. Encouraging moderate physical activity and consumption of certain foods may, in part, decrease the precipitating risks of breast cancer. More studies and research are needed to confirm these findings.

Nuclear receptor gene polymorphisms and warfarin dose requirements in the Quebec Warfarin Cohort

Warfarin is primarily metabolized by cytochrome 2C9, encoded by gene CYP2C9. Here, we investigated whether variants in nuclear receptor genes which regulate the expression of CYP2C9 are associated with warfarin response. We used data from 906 warfarin users from the Quebec Warfarin Cohort (QWC) and tested the association of warfarin dose requirement at 3 months following the initiation of therapy in nine nuclear receptor genes: NR1I3, NR1I2, NR3C1, ESR1, GATA4, RXRA, VDR, CEBPA, and HNF4A. Three correlated SNPs in the VDR gene (rs4760658, rs11168292, and rs11168293) were associated with dose requirements of warfarin (P = 2.68 × 10^-5, P = 5.81 × 10^-4, and P = 5.94 × 10^-4, respectively). Required doses of warfarin were the highest for homozygotes of the minor allele at the VDR variants (P < 0.0026). Variants in the VDR gene were associated with the variability in response to warfarin, emphasizing the possible clinical relevance of nuclear receptor gene variants on the inter-individual variability in drug metabolism.

SNPs related to vitamin D and breast cancer risk: a case-control study

BACKGROUND

It has been suggested that vitamin D might protect from breast cancer, although studies on levels of vitamin D in association with breast cancer have been inconsistent. Genome-wide association studies (GWASs) have identified several single-nucleotide polymorphisms (SNPs) to be associated with vitamin D. The aim of this study was to investigate such vitamin D-SNP associations in relation to subsequent breast cancer risk. A first step included verification of these SNPs as determinants of vitamin D levels.

METHODS

The Malmö Diet and Cancer Study included 17,035 women in a prospective cohort. Genotyping was performed and was successful in 4058 nonrelated women from this cohort in which 865 were diagnosed with breast cancer. Levels of vitamin D (25-hydroxyvitamin D) were available for 700 of the breast cancer cases and 643 of unaffected control subjects. SNPs previously associated with vitamin D in GWASs were identified. Logistic regression analyses yielding ORs with 95% CIs were performed to investigate selected SNPs in relation to low levels of vitamin D (below median) as well as to the risk of breast cancer.

RESULTS

The majority of SNPs previously associated with levels of vitamin D showed a statistically significant association with circulating vitamin D levels. Heterozygotes of one SNP (rs12239582) were found to have a statistically significant association with a low risk of breast cancer (OR 0.82, 95% CI 0.68-0.99), and minor homozygotes of the same SNP were found to have a tendency towards a low risk of being in the group with low vitamin D levels (OR 0.72, 95% CI 0.52-1.00). Results from stratified analyses showed diverse associations with breast cancer risk for a few of the tested SNPs, depending on whether vitamin D level was high or low.

CONCLUSIONS

SNPs associated with vitamin D may also be associated with the risk of breast cancer. Even if such a risk is small, the allele frequency of the SNP variants is high, and therefore the population attributable risk could be substantial. It is also possible that vitamin D levels may interact with genomic traits with regard to breast cancer risk.

Single-Nucleotide Polymorphisms in Vitamin D-Related Genes May Modify Vitamin D-Breast Cancer Associations

Background: We previously observed that high serum 25-hydroxyvitamin D (25(OH)D; >38.0 ng/mL) was inversely associated with breast cancer. Here, we examined effect modification by SNPs in vitamin D-related genes.Methods: The Sister Study enrolled 50,884 U.S. women who had a sister with breast cancer, but who had never had breast cancer themselves. Using a case-cohort design, we compared 1,524 women who developed breast cancer within 5 years to 1,810 randomly selected participants. We estimated ratios of HRs (RHRs) for the 25(OH)D-breast cancer association per copy of the minor allele using Cox proportional hazards models. We considered 82 SNPs in 7 vitamin D-related genes (CYP24A1, CYP27B1, CYP2R1, GC, DHCR7/NADSYN1, RXRA, and VDR). We also tested gene-based interactions with 25(OH)D.Results: The SNP with the smallest interaction P value was rs4328262 in VDR (P = 0.0008); the 25(OH)D HR was 0.92 [95% confidence interval (CI), 0.68-1.24] among those homozygous for the common allele, and the minor allele was estimated to decrease the HR by 33% per copy (RHR = 0.67; 95% CI, 0.53-0.85). Five other VDR SNPs showed evidence of interaction at P < 0.05, as did one SNP in CYP2R1 and one in RXRA As a group, the 82 SNPs showed evidence of multiplicative interaction with 25(OH)D (P = 0.04). In gene-based tests, only VDR showed strong evidence of interaction (P = 0.04).Conclusions: SNPs in vitamin D-related genes may modify the association between serum 25(OH)D and breast cancer.Impact: This work strengthens the evidence for protective effects of vitamin D. Cancer Epidemiol Biomarkers Prev; 26(12); 1761-71. ©2017 AACR.

Phytotherapy and Nutritional Supplements on Breast Cancer

Breast cancer is the most frequent type of nonskin malignancy among women worldwide. In general, conventional cancer treatment options (i.e., surgery, radiotherapy, chemotherapy, biological therapy, and hormone therapy) are not completely effective. Recurrence and other pathologic situations are still an issue in breast cancer patients due to side effects, toxicity of drugs in normal cells, and aggressive behaviour of the tumours. From this point of view, breast cancer therapy and adjuvant methods represent a promising and challenging field for researchers. In the last few years, the use of some types of complementary medicines by women with a history of breast cancer has significantly increased such as phytotherapeutic products and nutritional supplements. Despite this, the use of such approaches in oncologic processes may be problematic and patient's health risks can arise such as interference with the efficacy of standard cancer treatment. The present review gives an overview of the most usual phytotherapeutic products and nutritional supplements with application in breast cancer patients as adjuvant approach. Regardless of the contradictory results of scientific evidence, we demonstrated the need to perform additional investigation, mainly well-designed clinical trials in order to establish correlations and allow for further validated outcomes concerning the efficacy, safety, and clinical evidence-based recommendation of these products.

Does adjuvant chemotherapy change bone mineral density and related serum biomarkers in women with breast cancer?

Background:

The primary objective of this study was to assess BMD change in Iranian females with breast cancer.

Methods:

A sample of 73 female breast cancer patients treated with adjuvant chemotherapy either alone or followed by radiotherapy between March 2013 and February 2016 were considered for this study. Bone mineral density (BMD) change was evaluated by measuring z-score of lumbar spine, femoral neck (right and left side) as well as biochemical measurements. With respect to WHO categorization for the treatment of osteoporosis, patients were categorized as normal BMD, osteopenic and all analysis was done separately.

Results:

In women with normal BMD, lumbar spine and femoral neck (right side) z-score decreased significantly by 15.7 and 39%, respectively (p<0.05). In osteoporosis group, there was no BMD change in any of the lumbar or femoral neck z-scores. However, in osteopenic patients, femoral neck BMD decreased significantly by 40.9% after 8 months (p=0.003). The level of all measured biomedical markers such as Ca, Alb, P and vitamin OHD decreased significantly in a follow-up visit in both osteoporosis and normal BMD.

Conclusion:

Our results revealed that adjuvant chemotherapy led to unfavorable effects on lumbar spine and femoral neck means z-score during 8 months. Also, unfavorable changes in biochemical markers appeared in all groups.