scholarly journals The association between weight at birth and breast cancer risk revisited using Mendelian randomisation

2018 ◽  
Author(s):  
Siddhartha P. Kar ◽  
Irene L. Andrulis ◽  
Hermann Brenner ◽  
Stephen Burgess ◽  
Jenny Chang-Claude ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Breast Cancer Risk ◽  
Cancer Risk ◽  
Adult Life ◽  
Data Availability ◽  
Alternative Methods ◽  
Sensitivity Analyses ◽  
Mendelian Randomisation ◽  
Age At Menarche ◽  
Increased Risk

AbstractObservational studies suggest that higher birth weight (BW) is associated with increased risk of breast cancer in adult life. We conducted a two-sample Mendelian randomisation (MR) study to assess whether this association is causal. Sixty independent single nucleotide polymorphisms (SNPs) known to be associated at P < 5 × 10-8 with BW were used to construct (1) a 41-SNP instrumental variable (IV) for univariable MR after removing SNPs with pleiotropic associations with other breast cancer risk factors and (2) a 49-SNP IV for multivariable MR after filtering SNPs for data availability. BW predicted by the 41-SNP IV was not associated with overall breast cancer risk in inverse-variance weighted (IVW) univariable MR analysis of genetic association data from 122,977 breast cancer cases and 105,974 controls (odds ratio = 0.86 per 500 g higher BW; 95% confidence interval: 0.73—1.01). Sensitivity analyses using four alternative methods and three alternative IVs, including an IV with 59 of the 60 BW-associated SNPs, yielded similar results. Multivariable MR adjusting for the effects of the 49-SNP IV on birth length, adult height, adult body mass index, age at menarche, and age at menopause using IVW and MR-Egger methods provided estimates consistent with univariable analyses. Results were also similar when all analyses were repeated after restricting to estrogen receptor-positive or -negative breast cancer cases. Point estimates of the odds ratios from most analyses performed indicated an inverse relationship between genetically-predicted BW and breast cancer. Thus, there is little evidence from MR to suggest that the previously observed association between higher BW and increased risk of breast cancer in adult life is causal.

scholarly journals Mendelian randomisation study of smoking exposure in relation to breast cancer risk

2021 ◽  
Author(s):  
Hanla A. Park ◽  
Sonja Neumeyer ◽  
Kyriaki Michailidou ◽  
Manjeet K. Bolla ◽  
Qin Wang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Breast Cancer Risk ◽  
Cancer Risk ◽  
Causal Effect ◽  
Association Studies ◽  
Sensitivity Analyses ◽  
Mendelian Randomisation ◽  
Genome Wide Association Studies ◽  
Nucleotide Polymorphisms ◽  
Smoking Exposure

Abstract Background Despite a modest association between tobacco smoking and breast cancer risk reported by recent epidemiological studies, it is still equivocal whether smoking is causally related to breast cancer risk. Methods We applied Mendelian randomisation (MR) to evaluate a potential causal effect of cigarette smoking on breast cancer risk. Both individual-level data as well as summary statistics for 164 single-nucleotide polymorphisms (SNPs) reported in genome-wide association studies of lifetime smoking index (LSI) or cigarette per day (CPD) were used to obtain MR effect estimates. Data from 108,420 invasive breast cancer cases and 87,681 controls were used for the LSI analysis and for the CPD analysis conducted among ever-smokers from 26,147 cancer cases and 26,072 controls. Sensitivity analyses were conducted to address pleiotropy. Results Genetically predicted LSI was associated with increased breast cancer risk (OR 1.18 per SD, 95% CI: 1.07–1.30, P = 0.11 × 10–2), but there was no evidence of association for genetically predicted CPD (OR 1.02, 95% CI: 0.78–1.19, P = 0.85). The sensitivity analyses yielded similar results and showed no strong evidence of pleiotropic effect. Conclusion Our MR study provides supportive evidence for a potential causal association with breast cancer risk for lifetime smoking exposure but not cigarettes per day among smokers.

scholarly journals The Menstrual Cycle Related Hormone Variations and Breast Cancer Risk: A Novel Theory

2020 ◽  
pp. 1-6
Author(s):  
Liang Xiaohui ◽  
Liang Xiaohui ◽  
Nicholas Taylor ◽  
Vixey Fang ◽  
Xiao Zhang
Keyword(s):  
Breast Cancer ◽  
Menstrual Cycle ◽  
Breast Cancer Risk ◽  
Cancer Risk ◽  
Average Length ◽  
Critical Role ◽  
Age At Menarche ◽  
Increased Risk ◽  
Novel Theory ◽  
The Difference

Background: The cumulative and excessive exposures to estrogen contributing to increased risk of breast cancer may be misleading. Methods: We proposed a novel theory to highlight that exposure to unstable estrogen levels may play a critical role in determining breast cancer risk among females as the change of endocrine environment may pose a risky environment to breast tissues for carcinogenesis. Particularly, we considered the menstrual cycle related estrogen variation (MCREV) as the primary hazard to breast cancer among females. Results: To describe MCREV, its intensity was defined as the difference between the highest and the lowest levels of estrogen within a menstrual cycle; its timing was defined as age at menarche and age at pregnancies (i.e. timing of cessation of exposure to this hazard); and its frequency and duration can both be defined as the total number of menstrual cycles, which is influenced by many factors including age of menarche, age of menopause, average length of one menstrual cycle, and durations and number of pregnancies and breastfeeding. Conclusions: The proposed MCREV theory may identify women at high-risk of breast cancer at an earlier age. The development of breast cancer might be weakened if suitable techniques to reduce the MCREV become clinically available. This novel theory opens a new door in breast cancer prevention and management.

СONTRIBUTION OF POLYMORPHIC VARIATION OF ТP53 AND XRCC1 GENES TO THE SUSCEPTIBILITY TO BREAST CANCER FOR WOMEN OF KYRGYZ AND BELARUSIAN NATIONALITY - A COMPARATIVE STUDY ON MULTIFACTOR DIMENSIONALITY REDUCTION METHODS

2018 ◽  
Vol 64 (1) ◽  
pp. 95-101
Author(s):  
Nazira Aldasheva ◽  
Vyacheslav Kipen ◽  
Zhaynagul Isakova ◽  
Sergey Melnov ◽  
Raisa Smolyakova ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Breast Cancer Risk ◽  
Cancer Risk ◽  
Dimensionality Reduction ◽  
Multifactor Dimensionality Reduction ◽  
Rflp Analysis ◽  
Kyrgyz Republic ◽  
Increased Risk ◽  
Polymorphic Variants ◽  
The Republic

Basing on Multifactor Dimensionality Reduction method we showed that polymorphic variants p.Q399R (rs25487, XRCC1) and p.P72R (rs1042522, TP53) correlated with increased risk of breast cancer for women from the Kyrgyz Republic and the Republic of Belarus. Cohort for investigation included patients with clinically verified breast cancer: 117 women from the Kyrgyz Republic (nationality - Kyrgyz) and 169 - of the Republic of Belarus (nationality - Belarusians). Group for comparison included (healthy patients without history of cancer pathology at the time of blood sampling) 102 patients from the Kyrgyz Republic, 185 - from the Republic of Belarus. Respectively genotyping of polymorphic variants p.Q399R (rs25487, XRCC1) and p.P72R (rs1042522, TP53) was done by PCR-RFLP. Analysis of the intergenic interactions conducted with MDR 3.0.2 software. Both ethnic groups showed an increase of breast cancer risk in the presence of alleles for SNPs Gln p.Q399R (XRCC1) in the heterozygous state: for the group “Kyrgyz” - OR=2,78 (95% CI=[1,60-4,82]), p=0,001; for the group “Belarusians” - OR=1,85 (95% СІ=[1Д1-2,82], p=0,004. Carriers with combination of alleles Gln (p.Q399R, XRCC1) and Pro (p.P72R, TP53) showed statistically significance increases of breast cancer risk as for patients from the Kyrgyz Republic (OR=2,89, 95% CI=[1,33-6,31]), so as for patients from the Republic of Belarus (OR=3,01, 95% CI=[0,79-11,56]).

scholarly journals Transiently increased risk of breast cancer after childbirth: implications for fertility treatments and surrogacy

2020 ◽  
Vol 35 (6) ◽  
pp. 1253-1255
Author(s):  
Zeev Blumenfeld ◽  
Norbert Gleicher ◽  
Eli Y Adashi
Keyword(s):  
Breast Cancer ◽  
Breast Cancer Risk ◽  
Cancer Risk ◽  
Meta Analysis ◽  
Small Degree ◽  
Short Term ◽  
Benefit Ratio ◽  
Professional Societies ◽  
Fertility Treatments ◽  
Increased Risk

Abstract Whereas longstanding dogma has purported that pregnancies protect women from breast cancer, a recent meta-analysis now mandates reconsideration since it reported an actual higher breast cancer risk for more than two decades after childbirth before the relative risk turns negative. Moreover, the risk of breast cancer appears higher for women having their first birth at an older age and with a family history and it is not reduced by breastfeeding. The process of obtaining informed consent for all fertility treatments, therefore, must make patients aware of the facts that every pregnancy, to a small degree, will increase the short-term breast cancer risk. This observation may be even more relevant in cases of surrogacy where women agree to conceive without deriving benefits of offspring from assuming the risk, thus creating a substantially different risk-benefit ratio. Consequently, it appears prudent for professional societies in the field to update recommendations regarding consent information for all fertility treatments but especially for treatments involving surrogacy.

Association of APC and MCC Polymorphisms with Increased Breast Cancer Risk in an Indian Population

2011 ◽  
Vol 26 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Nupur Mukherjee ◽  
Nilanjana Bhattacharya ◽  
Satyabrata Sinha ◽  
Neyaz Alam ◽  
Runu Chakravarti ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Breast Cancer Risk ◽  
Cancer Risk ◽  
Signaling Pathway ◽  
Wnt Signaling Pathway ◽  
Minor Allele ◽  
Nucleotide Polymorphisms ◽  
Breast Cancer Patients ◽  
Increased Risk ◽  
Risk Of Cancer

The adenomatous polyposis coli (APC) and mutated in colorectal cancer (MCC) genes are key regulatory genes of the Wnt/β-catenin signaling pathway, which are independently involved in maintaining low levels of β-catenin in the cell. In addition to genetic and epigenetic alterations, some genetic polymorphisms in the genes associated with the Wnt signaling pathway have been reported to be associated with an increased risk of cancer, including breast cancer. In the present study we analyzed the association of genotype and haplotype status of two single nucleotide polymorphisms (SNPs), rs2229992 and rs11283943, in the APC and MCC genes, respectively, with an increased risk of breast carcinogenesis in a breast cancer and control population from eastern India. We observed a significant association of the rs11283943 SNP with increased breast cancer risk. Two specific haplotypes involving the minor allele of rs11283943 were found to be associated with an increased breast cancer risk. Kaplan-Meier curves showed a significant association of the 2–2 genotype (genotype homozygous for the rs11283943 minor allele) with decreased survival (p=0.045) of the breast cancer patients in our study, in particular patients with early-onset BC.

Use of Statins and Breast Cancer: A Meta-Analysis of Seven Randomized Clinical Trials and Nine Observational Studies

2005 ◽  
Vol 23 (34) ◽  
pp. 8606-8612 ◽  
Author(s):  
Stefanos Bonovas ◽  
Kalitsa Filioussi ◽  
Nikolaos Tsavaris ◽  
Nikolaos M. Sitaras
Keyword(s):  
Breast Cancer ◽  
Breast Cancer Risk ◽  
Cancer Risk ◽  
Publication Bias ◽  
Observational Studies ◽  
Fixed Effects ◽  
Randomized Clinical Trials ◽  
Meta Analysis ◽  
Sensitivity Analyses ◽  
Fixed Effects Model

Purpose A growing body of evidence suggests that statins may have chemopreventive potential against breast cancer. Laboratory studies demonstrate that statins induce apoptosis and reduce cell invasiveness in various cell lines, including breast carcinoma cells. However, the clinical relevance of these data remains unclear. The nonconclusive nature of the epidemiologic data prompted us to conduct a detailed meta-analysis of the studies published on the subject in peer-reviewed literature. Patients and Methods A comprehensive search for articles published up until 2005 was performed; reviews of each study were conducted; and data were abstracted. Before meta-analysis, the studies were evaluated for publication bias and heterogeneity. Pooled relative risk (RR) estimates and 95% CIs were calculated using the random and the fixed-effects models. Subgroup and sensitivity analyses were also performed. Results Seven large randomized trials and nine observational studies (five case-control and four cohort studies) contributed to the analysis. We found no evidence of publication bias or heterogeneity among the studies. Statin use did not significantly affect breast cancer risk (fixed effects model: RR = 1.03; 95% CI, 0.93 to 1.14; random effects model: RR = 1.02; 95% CI, 0.89 to 1.18). When the analyses were stratified into subgroups, there was no evidence that study design substantially influenced the estimate of effects. Furthermore, the sensitivity analysis confirmed the stability of our results. Conclusion Our meta-analysis findings do not support a protective effect of statins against breast cancer. However, this conclusion is limited by the relatively short follow-up times of the studies analyzed. Further studies are required to investigate the potential decrease in breast cancer risk among long-term statin users.

scholarly journals Pubertal timing and breast cancer risk in the Sister Study cohort

2020 ◽  
Vol 22 (1) ◽  
Author(s):  
Mandy Goldberg ◽  
Aimee A. D’Aloisio ◽  
Katie M. O’Brien ◽  
Shanshan Zhao ◽  
Dale P. Sandler
Keyword(s):  
Breast Cancer ◽  
Risk Factor ◽  
Family History ◽  
Breast Cancer Risk ◽  
Cancer Risk ◽  
Birth Cohort ◽  
Pubertal Timing ◽  
Age At Menarche ◽  
Race Ethnicity ◽  
Pubertal Tempo

Abstract Background Earlier age at menarche is an established risk factor for breast cancer. While age at menarche has been fairly stable over the past half-century, age at breast development (thelarche) has continued to decrease. Recently, earlier age at thelarche and a longer time between thelarche and menarche (pubertal tempo) were shown to be associated with increased breast cancer risk. Our objective was to examine how breast cancer risk was associated with pubertal timing and tempo in a prospective US cohort. Methods Women ages 35–74 years without a history of breast cancer, but who had a sister previously diagnosed with breast cancer, were enrolled in the Sister Study from 2003 to 2009 (N = 50,884). At enrollment, participants reported their ages at thelarche and menarche. Pubertal tempo was age at menarche minus age at thelarche. We estimated adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for each pubertal milestone and risk of breast cancer (invasive or ductal carcinoma in situ) using Cox proportional hazards regression. We examined whether associations between age at thelarche and breast cancer risk were modified by birth cohort, race/ethnicity, weight at age 10, and extent of breast cancer family history, as characterized by a Bayesian score based on first-degree family structure. Results During follow-up (mean = 9.3 years), 3295 eligible women were diagnosed with breast cancer. Early ages at thelarche (HR = 1.23, 95% CI 1.03–1.46 for < 10 vs. 12–13 years) and menarche (HR = 1.10, 95% CI 1.01–1.20 for < 12 vs. 12–13 years) were positively associated with breast cancer risk. Pubertal tempo was not associated with breast cancer risk (HR = 0.99, 95% CI 0.97–1.02 per 1-year longer tempo). When considering early thelarche (< 10 years) and early menarche (< 12 years) jointly, women with both had a 30% greater risk of breast cancer compared with women with neither risk factor (95% CI 1.07–1.57). The association between age at thelarche and breast cancer risk did not significantly vary by birth cohort, race/ethnicity, childhood weight, or Bayesian family history score. Conclusions Earlier ages at thelarche and menarche may enhance susceptibility to breast carcinogenesis. Age at thelarche is an important risk factor to consider given secular trends towards earlier development.

scholarly journals Biological Aging Marker p16INK4a in T Cells and Breast Cancer Risk

Cancers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3122
Author(s):  
Jie Shen ◽  
Renduo Song ◽  
Bernard F. Fuemmeler ◽  
Kandace P. McGuire ◽  
Wong-Ho Chow ◽  
...  
Keyword(s):  
Breast Cancer ◽  
T Cells ◽  
Breast Cancer Risk ◽  
Cancer Risk ◽  
Mrna Expression ◽  
Cellular Senescence ◽  
Human Cancer ◽  
Biological Aging ◽  
Increased Risk ◽  
Discovery Stage

Prior research has demonstrated that altered telomere length, a well-known marker for biological aging, is associated with various types of human cancer. However, whether such association extends to additional hallmarks of biological aging, including cellular senescence, has not been determined yet. In this two-stage study, we assessed the association between p16INK4a mRNA expression in T cells, a marker of cellular senescence, and breast cancer risk. The discovery stage included 352 breast cancer patients and 324 healthy controls. p16INK4a mRNA expression was significantly higher in individuals who were older, Black, and had family history of cancer than their counterparts in both cases and controls. p16INK4a mRNA expression also differed by marital status, annual income, and smoking status in cases. In the discovery stage, we found that increased p16INK4a mRNA expression was associated with 1.40-fold increased risk of breast cancer (OR = 1.40; 95%CI: 1.21, 1.68; p < 0.001). A marginally significant association was further observed in the validation stage with 47 cases and 48 controls using pre-diagnostic samples (OR = 1.28; 95%CI: 0.98, 2.97; p = 0.053). In addition, we found that p16INK4a mRNA expression was higher in tumors with selected aggressive characteristics (e.g., poorly differentiated and large tumors) than their counterparts. In summary, our results demonstrate that higher p16INK4a mRNA expression in T cells is a risk factor for breast cancer and further support the role of biological aging in the etiology of breast cancer development. Novelty and Impact Statements: The results from this study provide evidence that cellular senescence, a process of biological aging, plays a role in breast cancer etiology. In addition, our results also support that social demographics may modify cellular senescence and biological aging.

scholarly journals Pubertal timing and breast density in young women: a prospective cohort study

2019 ◽  
Vol 21 (1) ◽  
Author(s):  
Lauren C. Houghton ◽  
Seungyoun Jung ◽  
Rebecca Troisi ◽  
Erin S. LeBlanc ◽  
Linda G. Snetselaar ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Breast Cancer Risk ◽  
Cancer Risk ◽  
Breast Density ◽  
Young Women ◽  
Geometric Mean ◽  
Age At Onset ◽  
Breast Development ◽  
Increased Risk ◽  
Pubertal Tempo

Abstract Background Earlier age at onset of pubertal events and longer intervals between them (tempo) have been associated with increased breast cancer risk. It is unknown whether the timing and tempo of puberty are associated with adult breast density, which could mediate the increased risk. Methods From 1988 to 1997, girls participating in the Dietary Intervention Study in Children (DISC) were clinically assessed annually between ages 8 and 17 years for Tanner stages of breast development (thelarche) and pubic hair (pubarche), and onset of menses (menarche) was self-reported. In 2006–2008, 182 participants then aged 25–29 years had their percent dense breast volume (%DBV) measured by magnetic resonance imaging. Multivariable, linear mixed-effects regression models adjusted for reproductive factors, demographics, and body size were used to evaluate associations of age and tempo of puberty events with %DBV. Results The mean (standard deviation) and range of %DBV were 27.6 (20.5) and 0.2–86.1. Age at thelarche was negatively associated with %DBV (p trend = 0.04), while pubertal tempo between thelarche and menarche was positively associated with %DBV (p trend = 0.007). %DBV was 40% higher in women whose thelarche-to-menarche tempo was 2.9 years or longer (geometric mean (95%CI) = 21.8% (18.2–26.2%)) compared to women whose thelarche-to-menarche tempo was less than 1.6 years (geometric mean (95%CI) = 15.6% (13.9–17.5%)). Conclusions Our results suggest that a slower pubertal tempo, i.e., greater number of months between thelarche and menarche, is associated with higher percent breast density in young women. Future research should examine whether breast density mediates the association between slower tempo and increased breast cancer risk.

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