Polygenic risk of coronary artery disease for long-term survivors of breast cancer.

Aim: Cardiovascular disease is a leading cause of death for long-term breast cancer survivors. We evaluated whether a polygenic risk score for coronary artery disease (CAD-PRS) was associated with the risk of incident CAD for survivors of unilateral or contralateral breast cancer.

Methods: The study included 1,307 women with breast cancer first diagnosed at age <55 years who participated in the WECARE Follow-up Study.

A new model to study season-of-conception effects on child neurodevelopment based on maternal history of seasonal affective disorder.

Season of birth/conception has been used to study neurodevelopmental risk in hundreds of studies, however the translational impact of this work remains limited. We propose a new model to study season-of- conception effects on neurodevelopment using maternal fall-winter seasonality as a key moderating variable, and provide initial empirical data to support this new approach. In an ongoing pregnancy cohort study we evaluated associations between season-of conception and maternal history of fall-winter Seasonal Affective Disorder (SAD) on child executive functioning in 520 children at age 54 months.

Breast Cancer Susceptibility Gene Sequence Variations and Development of Contralateral Breast Cancer.

Importance: Heterogeneity in development of estrogen receptor (ER)-specific first primary breast cancer exists due to deleterious germline variants in moderate- to high-penetrance breast cancer susceptibility genes, but it is unknown if these associations occur in ER-specific CBC.

Objective: To determine the association of deleterious germline variants in breast cancer susceptibility genes with ER-specific CBC development and whether ER status of the first primary breast cancer modifies these associations.

Design, Setting, And Participants: This case-control study included CBC cases and matched unilateral breast cancer controls from The Women's Environment, Cancer, and Radiation Epidemiology (WECARE) Study, a population-based case-control study.

The association between maternal depression and anxiety symptoms during pregnancy and child sleep patterns at age 3 years.

Background: Childhood sleep problems are common and impact physical and emotional health. Prior work suggests that prenatal maternal depression and anxiety associate with disturbed child sleep in infancy. The current study evaluated whether these same associations extend to children at 3 years of age, and if so, whether the timing of symptoms in pregnancy is relevant.

Pregnancy-Related Factors and Breast Cancer Risk for Women Across a Range of Familial Risk.

Importance: Few studies have investigated whether the associations between pregnancy-related factors and breast cancer (BC) risk differ by underlying BC susceptibility. Evidence regarding variation in BC risk is critical to understanding BC causes and for developing effective risk-based screening guidelines.

Objective: To examine the association between pregnancy-related factors and BC risk, including modification by a of BC where scores are based on age and BC family history.

Agreement of medical record abstraction and self-report of breast cancer treatment with an extended recall window.

Background: Medical record abstraction (MRA) and self-report questionnaires are two methods frequently used to ascertain cancer treatment information. Prior studies have shown excellent agreement between MRA and self-report, but it is unknown how a recall window longer than 3 years may affect this agreement.

Methods: The Women's Environmental Cancer and Radiation Epidemiology (WECARE) Study is a multicenter, population-based case-control study of controls with unilateral breast cancer individually matched to cases with contralateral breast cancer.

Case-Case Genome-Wide Analyses Identify Subtype-Informative Variants That Confer Risk for Breast Cancer.

Breast cancer includes several subtypes with distinct characteristic biological, pathologic, and clinical features. Elucidating subtype-specific genetic etiology could provide insights into the heterogeneity of breast cancer to facilitate the development of improved prevention and treatment approaches. In this study, we conducted pairwise case-case comparisons among five breast cancer subtypes by applying a case-case genome-wide association study (CC-GWAS) approach to summary statistics data of the Breast Cancer Association Consortium.

A genome-wide association study of contralateral breast cancer in the Women's Environmental Cancer and Radiation Epidemiology Study.

Background: Contralateral breast cancer (CBC) is the most common second primary cancer diagnosed in breast cancer survivors, yet the understanding of the genetic susceptibility of CBC, particularly with respect to common variants, remains incomplete. This study aimed to investigate the genetic basis of CBC to better understand this malignancy.

Findings: We performed a genome-wide association analysis in the Women's Environmental Cancer and Radiation Epidemiology (WECARE) Study of women with first breast cancer diagnosed at age < 55 years including 1161 with CBC who served as cases and 1668 with unilateral breast cancer (UBC) who served as controls.

Childhood physical activity and pubertal timing: findings from the LEGACY girls study.

Background: There is limited research on whether physical activity (PA) in early childhood is associated with the timing of pubertal events in girls.

Methods: We used data collected over 2011-16 from the LEGACY Girls Study (n = 984; primarily aged 6-13 years at study enrolment), a multicentre North American cohort enriched for girls with a breast cancer family history (BCFH), to evaluate if PA is associated with age at thelarche, pubarche and menarche. Maternal-reported questionnaire data measured puberty outcomes, PA in early childhood (ages 3-5 years) and total metabolic equivalents of organized PA in middle childhood (ages 7-9 years).

Maternal major depression during early pregnancy is associated with impaired child executive functioning at 4.5 years of age.

Background: Maternal depression is a serious condition that affects up to 1 in 7 pregnancies. Despite evidence linking maternal depression to pregnancy complications and adverse fetal outcomes, there remain large gaps in its identification and treatment. More work is needed to define the specific timing and severity of depression that most urgently requires intervention, where feasible, to protect maternal health and the developing fetus.

Cognitive and Emotional Well-Being of Preschool Children Before and During the COVID-19 Pandemic.

Importance: The association between COVID-19 social disruption and young children's development is largely unknown.

Objective: To examine associations of pandemic exposure with neurocognitive and socioemotional development at 24 and 54 months of age.

Design, Setting, And Participants: This cross-sectional study evaluated associations between pandemic exposure vs nonexposure and developmental outcomes with covariate adjustment using data from the Ontario Birth Study collected between February 2018 and June 2022.

Trends in Radiation Dose to the Contralateral Breast During Breast Cancer Radiation Therapy.

Over 4 million survivors of breast cancer live in the United States, 35% of whom were treated before 2009. Approximately half of patients with breast cancer receive radiation therapy, which exposes the untreated contralateral breast to radiation and increases the risk of a subsequent contralateral breast cancer (CBC). Radiation oncology has strived to reduce unwanted radiation dose, but it is unknown whether a corresponding decline in actual dose received to the untreated contralateral breast has occurred.

Association between estimated cardiorespiratory fitness and breast cancer: a prospective cohort study.

Objective: To examine the association between cardiorespiratory fitness (CRF) and the risk of breast cancer in postmenopausal women.

Methods: This study used data from 17 840 cancer-free postmenopausal women with a CRF assessment from the UK Biobank. High estimated CRF (eCRF) was categorised as being 80th percentile within 10-year age bands.

Diet Quality and All-Cause Mortality in Women with Breast Cancer from the Breast Cancer Family Registry.

Background: The impact of diet on breast cancer survival remains inconclusive. We assessed associations of all-cause mortality with adherence to the four diet quality indices: Healthy Eating Index-2015 (HEI-2015), Alternative Healthy Eating Index (AHEI), Alternative Mediterranean Diet (aMED), and Dietary Approaches to Stop Hypertension (DASH).

Methods: Dietary intake data were evaluated for 6,157 North American women enrolled in the Breast Cancer Family Registry who had been diagnosed with invasive breast cancer from 1993 to 2011 and were followed through 2018.

A harmonized analysis of five Canadian pregnancy cohort studies: exploring the characteristics and pregnancy outcomes associated with prenatal alcohol exposure.

Background: As a teratogen, alcohol exposure during pregnancy can impact fetal development and result in adverse birth outcomes. Despite the clinical and social importance of prenatal alcohol use, limited routinely collected information or epidemiological data exists in Canada. The aim of this study was to pool data from multiple Canadian cohort studies to identify sociodemographic characteristics before and during pregnancy that were associated with alcohol consumption during pregnancy and to assess the impact of different patterns of alcohol use on birth outcomes.

Increasing maternal age predicts placental protein expression critical for fetal serotonin metabolism: Potential implications for neurodevelopmental research.

High fetal exposure to serotonin and increasing maternal age both contribute to the risk for neurodevelopmental disorders. While identifying covariates for a study of placental protein expression, we found a significant negative correlation between maternal age and the expression of monoamine oxidase A (MAOA), and a significant positive correlation between maternal age and the expression of the serotonin transporter SERT. MAOA and SERT play key roles in placental serotonin metabolism relevant to fetal neurodevelopment.

Maternal acetaminophen use and cognitive development at 4 years: the Ontario Birth Study.

Background: Studies have suggested a link between prenatal maternal acetaminophen use and adverse developmental outcomes in children. However, there exists a knowledge gap regarding overall cognitive development and use of acetaminophen, especially concerning the timing of use in pregnancy. This study aimed to characterize the relationship between maternal acetaminophen use and cognitive development at 4 years.

Maternal and prenatal factors and age at thelarche in the LEGACY Girls Study cohort: implications for breast cancer risk.

Background: Earlier onset of breast development (thelarche) is associated with increased breast cancer risk. Identifying modifiable factors associated with earlier thelarche may provide an opportunity for breast cancer risk reduction starting early in life, which could especially benefit girls with a greater absolute risk of breast cancer due to family history.

Methods: We assessed associations of maternal pre-pregnancy body mass index (BMI), physical activity during pregnancy, gestational weight gain and daughters' weight and length at birth with age at thelarche using longitudinal Weibull models in 1031 girls in the Lessons in Epidemiology and Genetics of Adult Cancer from Youth (LEGACY) Girls Study-a prospective cohort of girls, half of whom have a breast cancer family history (BCFH).

Association of contralateral breast cancer risk with mammographic density defined at higher-than-conventional intensity thresholds.

Mammographic dense area (MDA) is an established predictor of future breast cancer risk. Recent studies have found that risk prediction might be improved by redefining MDA in effect at higher-than-conventional intensity thresholds. We assessed whether such higher-intensity MDA measures gave stronger prediction of subsequent contralateral breast cancer (CBC) risk using the Women's Environment, Cancer, and Radiation Epidemiology (WECARE) Study, a population-based CBC case-control study of ≥1 year survivors of unilateral breast cancer diagnosed between 1990 and 2008.

Maternal prenatal psychological distress and vitamin intake with children's neurocognitive development.

Background: Maternal prenatal psychological distress (PPD) is increasingly linked to sub-optimal child neurodevelopment. Daily intake of prenatal vitamin during pre-conception and early pregnancy may ameliorate the effects of PPD on cognition in the offspring.

Methods: PPD was assessed in early (12-16 weeks) and late (28-32 weeks) gestation in the Ontario Birth Study.

Evaluating depression and anxiety throughout pregnancy and after birth: impact of the COVID-19 pandemic.

Background: The COVID-19 pandemic presents unique social, economic, and psychological challenges for individuals globally. Thus, women who are pregnant face unprecedented mental health challenges.

Objective: We sought to determine the impact of the pandemic on perinatal depression and anxiety in a longitudinal pregnancy cohort.

Body mass index rebound and pubertal timing in girls with and without a family history of breast cancer: the LEGACY girls study.

Background: Heavier body mass index (BMI) is the most established predictor of earlier age at puberty. However, it is unknown whether the timing of the childhood switch to heavier BMI (age at BMI rebound) also matters for puberty.

Methods: In the LEGACY Girls Study (n = 1040), a longitudinal cohort enriched with girls with a family history of breast cancer, we collected paediatric growth chart data from 852 girls and assessed pubertal development every 6 months.