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Study Question: Can additional genetic variants for circulating anti-Müllerian hormone (AMH) levels be identified through a genome-wide association study (GWAS) meta-analysis including a large sample of premenopausal women?Summary Answer: We identified four loci associated with AMH levels at P < 5 × 10-8: the previously reported MCM8 locus and three novel signals in or near AMH, TEX41 and CDCA7.What Is Known Already: AMH is expressed by antral stage ovarian follicles in women, and variation in age-specific circulating AMH levels has been associated with disease outcomes. However, the physiological mechanisms underlying these AMH-disease associations are largely unknown.Study Design, Size, Duration: We performed a GWAS meta-analysis in which we combined summary statistics of a previous AMH GWAS with GWAS data from 3705 additional women from three different cohorts.Participants/materials, Setting, Methods: In total, we included data from 7049 premenopausal female participants of European ancestry. The median age of study participants ranged from 15.3 to 48 years across cohorts. Circulating AMH levels were measured in either serum or plasma samples using different ELISA assays. Study-specific analyses were adjusted for age at blood collection and population stratification, and summary statistics were meta-analysed using a standard error-weighted approach. Subsequently, we functionally annotated GWAS variants that reached genome-wide significance (P < 5 × 10-8). We also performed a gene-based GWAS, pathway analysis and linkage disequilibrium score regression and Mendelian randomization (MR) analyses.Main Results and the Role Of Chance: We identified four loci associated with AMH levels at P < 5 × 10-8: the previously reported MCM8 locus and three novel signals in or near AMH, TEX41 and CDCA7. The strongest signal was a missense variant in the AMH gene (rs10417628). Most prioritized genes at the other three identified loci were involved in cell cycle regulation. Genetic correlation analyses indicated a strong positive correlation among single nucleotide polymorphisms for AMH levels and for age at menopause (rg = 0.82, FDR = 0.003). Exploratory two-sample MR analyses did not support causal effects of AMH on breast cancer or polycystic ovary syndrome risk, but should be interpreted with caution as they may be underpowered and the validity of genetic instruments could not be extensively explored.Large Scale Data: The full AMH GWAS summary statistics will made available after publication through the GWAS catalog (https://www.ebi.ac.uk/gwas/).Limitations, Reasons For Caution: Whilst this study doubled the sample size of the most recent GWAS, the statistical power is still relatively low. As a result, we may still lack power to identify more genetic variants for AMH and to determine causal effects of AMH on, for example, breast cancer. Also, follow-up studies are needed to investigate whether the signal for the AMH gene is caused by reduced AMH detection by certain assays instead of actual lower circulating AMH levels.Wider Implications Of the Findings: Genes mapped to the MCM8, TEX41 and CDCA7 loci are involved in the cell cycle and processes such as DNA replication and apoptosis. The mechanism underlying their associations with AMH may affect the size of the ovarian follicle pool. Altogether, our results provide more insight into the biology of AMH and, accordingly, the biological processes involved in ovarian ageing.Study Funding/competing Interest(s): Nurses' Health Study and Nurses' Health Study II were supported by research grants from the National Institutes of Health (CA172726, CA186107, CA50385, CA87969, CA49449, CA67262, CA178949). The UK Medical Research Council and Wellcome (217065/Z/19/Z) and the University of Bristol provide core support for ALSPAC. This publication is the work of the listed authors, who will serve as guarantors for the contents of this article. A comprehensive list of grants funding is available on the ALSPAC website (http://www.bristol.ac.uk/alspac/external/documents/grant-acknowledgements.pdf). Funding for the collection of genotype and phenotype data used here was provided by the British Heart Foundation (SP/07/008/24066), Wellcome (WT092830M and WT08806) and UK Medical Research Council (G1001357). M.C.B., A.L.G.S. and D.A.L. work in a unit that is funded by the University of Bristol and UK Medical Research Council (MC_UU_00011/6). M.C.B.'s contribution to this work was funded by a UK Medical Research Council Skills Development Fellowship (MR/P014054/1) and D.A.L. is a National Institute of Health Research Senior Investigator (NF-0616-10102). A.L.G.S. was supported by the study of Dynamic longitudinal exposome trajectories in cardiovascular and metabolic non-communicable diseases (H2020-SC1-2019-Single-Stage-RTD, project ID 874739). The Doetinchem Cohort Study was financially supported by the Ministry of Health, Welfare and Sports of the Netherlands. The funder had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript. Ansh Labs performed the AMH measurements for the Doetinchem Cohort Study free of charge. Ansh Labs was not involved in the data analysis, interpretation or reporting, nor was it financially involved in any aspect of the study. R.M.G.V. was funded by the Honours Track of MSc Epidemiology, University Medical Center Utrecht with a grant from the Netherlands Organization for Scientific Research (NWO) (022.005.021). The Study of Women's Health Across the Nation (SWAN) has grant support from the National Institutes of Health (NIH), DHHS, through the National Institute on Aging (NIA), the National Institute of Nursing Research (NINR) and the NIH Office of Research on Women's Health (ORWH) (U01NR004061; U01AG012505, U01AG012535, U01AG012531, U01AG012539, U01AG012546, U01AG012553, U01AG012554, U01AG012495). The SWAN Genomic Analyses and SWAN Legacy have grant support from the NIA (U01AG017719). The Generations Study was funded by Breast Cancer Now and the Institute of Cancer Research (ICR). The ICR acknowledges NHS funding to the NIHR Biomedical Research Centre. The content of this manuscript is solely the responsibility of the authors and does not necessarily represent official views of the funders. The Sister Study was funded by the Intramural Research Program of the National Institutes of Health (NIH), National Institute of Environmental Health Sciences (Z01-ES044005 to D.P.S.); the AMH assays were supported by the Avon Foundation (02-2012-065 to H.B. Nichols and D.P.S.). The breast cancer genome-wide association analyses were supported by the Government of Canada through Genome Canada and the Canadian Institutes of Health Research, the 'Ministère de l'Économie, de la Science et de l'Innovation du Québec' through Genome Québec and grant PSR-SIIRI-701, The National Institutes of Health (U19 CA148065, X01HG007492), Cancer Research UK (C1287/A10118, C1287/A16563, C1287/A10710) and The European Union (HEALTH-F2-2009-223175 and H2020 633784 and 634935). All studies and funders are listed in Michailidou et al. (Nature, 2017). F.J.M.B. has received fees and grant support from Merck Serono and Ferring BV. D.A.L. has received financial support from several national and international government and charitable funders as well as from Medtronic Ltd and Roche Diagnostics for research that is unrelated to this study. N.S. is scientific consultant for Ansh Laboratories. The other authors declare no competing interests. [ABSTRACT FROM AUTHOR]

Background: The history of gestational diabetes mellitus (GDM) has been associated with breast cancer risk in some studies, particularly in young women, but results of cohort studies are conflicting.Methods: We pooled data from 257 290 young (age <55 years) women from five cohorts. We used multivariable Cox proportional-hazards regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between GDM history and risk of breast cancer, overall and by oestrogen receptor (ER) status, before age 55 years, adjusted for established breast cancer risk factors.Results: Five percent of women reported a history of GDM and 6842 women reported an incident breast-cancer diagnosis (median follow-up = 16 years; maximum = 24 years). Compared with parous women without GDM, women with a history of GDM were not at increased risk of young-onset breast cancer overall (HR = 0.90; 95% CI: 0.78, 1.03) or by ER status (HR = 0.96; 95% CI: 0.79, 1.16 for ER-positive; HR = 1.07; 95% CI: 0.78, 1.47 for ER-negative). Compared with nulliparous women, parous women with a history of GDM had a lower risk of breast cancer overall (HR = 0.79; 95% CI: 0.68, 0.91) and of ER-positive (HR = 0.82; 95% CI: 0.66, 1.02) but not ER-negative (HR = 1.09; 95% CI: 0.76, 1.54) invasive breast cancer. These results were consistent with the HRs comparing parous women without GDM to nulliparous women.Conclusions: Results of this analysis do not support the hypothesis that GDM is a risk factor for breast cancer in young women. Our findings suggest that the well-established protective effect of parity on risk of ER-positive breast cancer persists even for pregnancies complicated by GDM. [ABSTRACT FROM AUTHOR]

Context: We previously reported that anti-Müllerian hormone (AMH), a marker of ovarian reserve, is positively associated with breast cancer risk, consistent with other studies.Objective: This study assessed whether risk factors for breast cancer are correlates of AMH concentration.Methods: This cross-sectional study included 3831 healthy premenopausal women (aged 21-57, 87% aged 35-49) from 10 cohort studies among the general population.Results: Adjusting for age and cohort, AMH positively associated with age at menarche (P < 0.0001) and parity (P = 0.0008) and inversely associated with hysterectomy/partial oophorectomy (P = 0.0008). Compared with women of normal weight, AMH was lower (relative geometric mean difference 27%, P < 0.0001) among women who were obese. Current oral contraceptive (OC) use and current/former smoking were associated with lower AMH concentration than never use (40% and 12% lower, respectively, P < 0.0001). We observed higher AMH concentrations among women who had had a benign breast biopsy (15% higher, P = 0.03), a surrogate for benign breast disease, an association that has not been reported. In analyses stratified by age (<40 vs ≥40), associations of AMH with body mass index and OCs were similar in younger and older women, while associations with the other factors (menarche, parity, hysterectomy/partial oophorectomy, smoking, and benign breast biopsy) were limited to women ≥40 (P-interaction < 0.05).Conclusion: This is the largest study of AMH and breast cancer risk factors among women from the general population (not presenting with infertility), and it suggests that most associations are limited to women over 40, who are approaching menopause and whose AMH concentration is declining. [ABSTRACT FROM AUTHOR]

Background: External validation of risk models is critical for risk-stratified breast cancer prevention. We used the Individualized Coherent Absolute Risk Estimation (iCARE) as a flexible tool for risk model development and comparative model validation and to make projections for population risk stratification.Methods: Performance of two recently developed models, one based on the Breast and Prostate Cancer Cohort Consortium analysis (iCARE-BPC3) and another based on a literature review (iCARE-Lit), were compared with two established models (Breast Cancer Risk Assessment Tool and International Breast Cancer Intervention Study Model) based on classical risk factors in a UK-based cohort of 64 874 white non-Hispanic women (863 patients) age 35-74 years. Risk projections in a target population of US white non-Hispanic women age 50-70 years assessed potential improvements in risk stratification by adding mammographic breast density (MD) and polygenic risk score (PRS).Results: The best calibrated models were iCARE-Lit (expected to observed number of cases [E/O] = 0.98, 95% confidence interval [CI] = 0.87 to 1.11) for women younger than 50 years, and iCARE-BPC3 (E/O = 1.00, 95% CI = 0.93 to 1.09) for women 50 years or older. Risk projections using iCARE-BPC3 indicated classical risk factors can identify approximately 500 000 women at moderate to high risk (>3% 5-year risk) in the target population. Addition of MD and a 313-variant PRS is expected to increase this number to approximately 3.5 million women, and among them, approximately 153 000 are expected to develop invasive breast cancer within 5 years.Conclusions: iCARE models based on classical risk factors perform similarly to or better than BCRAT or IBIS in white non-Hispanic women. Addition of MD and PRS can lead to substantial improvements in risk stratification. However, these integrated models require independent prospective validation before broad clinical applications. [ABSTRACT FROM AUTHOR]

A balanced robertsonian translocation (rob) results from fusion of 2 acrocentric chromosomes. Carriers are phenotypically normal and are often diagnosed because of recurrent miscarriages, infertility, or aneuploid offspring. Mortality and site-specific cancer risks in carriers have not been prospectively investigated. We followed 1,987 carriers diagnosed in Great Britain for deaths and cancer risk, over an average of 24.1 years. Standardized mortality and incidence ratios were calculated comparing the number of observed events against population rates. Overall mortality was higher for carriers diagnosed before age 15 years (standardized mortality ratio (SMR) = 2.00, 95% confidence interval (CI): 1.09, 3.35), similar for those diagnosed aged 15–44 years (SMR = 1.06, 95% CI: 0.86–1.28), and lower for those diagnosed aged 45–84 years (SMR = 0.81, 95% CI: 0.68, 0.95). Cancer incidence was higher for non-Hodgkin lymphoma (standardized incidence ratio (SIR) = 1.90, 95% CI: 1.01, 3.24) and childhood leukemia (SIR = 14.5, 95% CI: 1.75, 52.2), the latter particularly in rob(15;21) carriers (SIR = 447.8, 95% CI: 11.3, 2,495). Rob(13;14) carriers had a higher breast cancer risk (SIR = 1.58, 95% CI: 1.12, 2.15). Mortality risks relative to the population in diagnosed carriers depend on age at cytogenetic diagnosis, possibly reflecting age-specific cytogenetic referral reasons. Carriers might be at greater risk of childhood leukemia and non-Hodgkin lymphoma and those diagnosed with rob(13;14) of breast cancer. [ABSTRACT FROM AUTHOR]

Study Question: Is the length of FMR1 repeat alleles within the normal range associated with the risk of early menopause?Summary Answer: The length of repeat alleles within the normal range does not substantially affect risk of early menopause.What Is Known Already: There is a strong, well-established relationship between length of premutation FMR1 alleles and age at menopause, suggesting that this relationship could continue into the normal range. Within the normal range, there is conflicting evidence; differences in ovarian reserve have been identified with FMR1 repeat allele length, but a recent population-based study did not find any association with age at menopause as a quantitative trait.Study Design, Size, Duration: We analysed cross-sectional baseline survey data collected at recruitment from 2004 to 2010 from a population-based, prospective epidemiological cohort study of >110 000 women to investigate whether repeat allele length was associated with early menopause.Participants/materials, Setting, Method: We included 4333 women from the Breakthrough Generations Study (BGS), of whom 2118 were early menopause cases (menopause under 46 years) and 2215 were controls. We analysed the relationship between length of FMR1 alleles and early menopause using logistic regression with allele length as continuous and categorical variables. We also conducted analyses with the outcome age at menopause as a quantitative trait as well as appropriate sensitivity and exploratory analyses.Main Results and the Role Of Chance: There was no association of the shorter or longer FMR1 allele or their combined genotype with the clinically relevant end point of early menopause in our main analysis. Likewise, there were no associations with age at menopause as a quantitative trait in our secondary analysis.Limitations, Reasons For Caution: Women with homozygous alleles in the normal range may have undetected FMR1 premutation alleles, although there was no evidence to suggest this. We estimate minor dilution of risk of early menopause from the likely inclusion of some women with menopause at over 45 years in the early menopause cases due to age-rounding bias in self-reports.Wider Implications Of the Findings: There is no robust evidence in this large study that variation within the normal range of FMR1 repeat alleles influences timing of menopause in the general population, which contradicts findings from some earlier, mainly smaller studies. The FMR1 CGG repeat polymorphism in the normal range is unlikely to contribute to genetic susceptibility to early menopause.Study Funding/competing Interests: We thank Breast Cancer Now and The Institute of Cancer Research for funding the BGS. The Institute of Cancer Research acknowledges NHS funding to the NIHR Biomedical Research Centre. The study was funded by the Wellcome Trust (grant number 085943). There are no competing interests.Trial Registration Number: Not applicable. [ABSTRACT FROM AUTHOR]

There has been a worldwide epidemic of obesity in recent decades. In animal studies, there is convincing evidence that light exposure causes weight gain, even when calorie intake and physical activity are held constant. Disruption of sleep and circadian rhythms by exposure to light at night (LAN) might be one mechanism contributing to the rise in obesity, but it has not been well-investigated in humans. Using multinomial logistic regression, we examined the association between exposure to LAN and obesity in questionnaire data from over 100,000 women in the Breakthrough Generations Study, a cohort study of women aged 16 years or older who were living in the United Kingdom and recruited during 2003–2012. The odds of obesity, measured using body mass index, waist:hip ratio, waist:height ratio, and waist circumference, increased with increasing levels of LAN exposure (P < 0.001), even after adjustment for potential confounders such as sleep duration, alcohol intake, physical activity, and current smoking. We found a significant association between LAN exposure and obesity which was not explained by potential confounders we could measure. While the possibility of residual confounding cannot be excluded, the pattern is intriguing, accords with the results of animal experiments, and warrants further investigation. [ABSTRACT FROM PUBLISHER]

The etiology of glioma is barely known. Epidemiologic studies have provided evidence for an inverse relation between glioma risk and allergic disease. Genome-wide association data have identified common genetic variants at 5p15.33 (rs2736100, TERT), 8q24.21 (rs4295627, CCDC26), 9p21.3 (rs4977756, CDKN2A-CDKN2B), 11q23.3 (rs498872, PHLDB1), and 20q13.33 (rs6010620, RTEL1) as determinants of glioma risk. The authors investigated whether there is interaction between the effects of allergy and these 5 variants on glioma risk. Data from 5 case-control studies carried out in Denmark, Finland, Sweden, and the United Kingdom (2000–2004) were used, totaling 1,029 cases and 1,668 controls. Risk was inversely associated with asthma, hay fever, eczema, and “any allergy,” significantly for each factor except asthma, and was significantly positively associated with number of risk alleles for each of the 5 single nucleotide polymorphisms. There was interaction between asthma and rs498872 (greater protective effect of asthma with increasing number of risk alleles; per-allele interaction odds ratio (OR) = 0.65, P = 0.041), between “any allergy” and rs4977756 (smaller protective effect; interaction OR = 1.27, P = 0.047), and between “any allergy” and rs6010620 (greater protective effect; interaction OR = 0.70, P = 0.017). Case-only analyses provided further support for atopy interactions for rs4977756 and rs498872. This study provides evidence for possible gene-environment interactions in glioma development. [ABSTRACT FROM PUBLISHER]

Background: Men with Klinefelter syndrome have one or more extra X chromosomes and have endocrine abnormalities. Case reports have led to suggestions that men with Klinefelter syndrome have elevated risks of several cancers, but published cohort studies have been relatively small. We conducted a nationwide cohort study to examine these risks. Methods: We followed a cohort of 3518 men who had been cytogenetically diagnosed with Klinefelter syndrome in Britain from 1959 through 2002 and compared their cancer incidence and mortality with that of men in the national population. All statistical tests were two-sided. Results: The standardized mortality ratio (SMR) for all cancers was 1.2 (95% confidence interval [CI] = 1.0 to 1.4). Compared with the general population, men with Klinefelter syndrome had higher mortality from lung cancer (SMR = 1.5, 95% CI = 1.0 to 2.0), breast cancer (SMR = 57.8, 95% CI = 18.8 to 135.0), and non-Hodgkin lymphoma (SMR = 3.5, 95% CI = 1.6 to 6.6) and lower mortality from prostate cancer (SMR = 0, 95% CI = 0 to 0.7). The standardized mortality ratios were particularly high for breast cancer among men with 47,XXY mosaicism (SMR = 222.8, 95% CI = 45.9 to 651.0) and for non-Hodgkin lymphoma among men with a 48,XXYY constitution (SMR = 36.7, 95% CI = 4.4 to 132.5). The cancer incidence data corroborated these associations. Conclusions: These results support a hormonal etiology for breast cancer in men and for prostate cancer and suggest that men with Klinefelter syndrome may be at substantially elevated risks for non-Hodgkin lymphoma, breast cancer, and, perhaps, lung cancer. [ABSTRACT FROM AUTHOR]