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). We used interval-censored Weibull parametric survival regression models with age as the time scale and adjusted for sociodemographic factors, and we tested for effect modification by BCFH. We used inverse odds weighting to test for mediation by body mass index-for-age z-score (BMIZ) measured at study enrolment. RESULTS: Being highly active vs inactive in early childhood was associated with later thelarche in girls with a BCFH [adjusted hazard ratio (aHR) = 0.39, 95% CI = 0.26-0.59), but not in girls without a BCFH. In all girls, irrespective of BCFH, being in the highest vs lowest quartile of organized PA in middle childhood was associated with later menarche (aHR = 0.70, 95% CI = 0.50-0.97). These associations remained after accounting for potential mediation by BMIZ. CONCLUSION: This study provides new data that PA in early childhood may be associated with later thelarche in girls with a BCFH, also further supporting an overall association between PA in middle childhood and later menarche.

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. We observed two loci (rs59657211, 9q32, SLC31A2/FAM225A and rs3815096, 6p22.1, TRIM31) with suggestive genome-wide significant associations (P < 1 × 10-6). We also found an increased risk of CBC associated with a breast cancer-specific polygenic risk score (PRS) comprised of 239 known breast cancer susceptibility single nucleotide polymorphisms (SNPs) (rate ratio per 1-SD change: 1.25; 95% confidence interval 1.14-1.36, P < 0.0001). The protective effect of chemotherapy on CBC risk was statistically significant only among patients with an elevated PRS (Pheterogeneity = 0.04). The AUC that included the PRS and known breast cancer risk factors was significantly elevated. CONCLUSIONS: The present GWAS identified two previously unreported loci with suggestive genome-wide significance. We also confirm that an elevated risk of CBC is associated with a comprehensive breast cancer susceptibility PRS that is independent of known breast cancer risk factors. These findings advance our understanding of genetic risk factors involved in CBC etiology.

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. OBJECTIVE: This study aimed to examine whether the timing and severity of maternal depression and/or anxiety during pregnancy affect child executive functioning at age 4.5 years. Executive functioning in the preschool years is a strong predictor of both school readiness and long-term quality of life. STUDY DESIGN: This longitudinal observational pregnancy cohort study included a sample of 323 mother-child dyads taking part in the Ontario Birth Study, an open pregnancy cohort in Toronto, Ontario, Canada. Maternal symptoms of depression and anxiety were assessed at 12 to 16 and 28 to 32 weeks of gestation and at the time of child testing at age 4.5 years using the 4-item Patient Health Questionnaire. Child executive functioning was measured during a home visit using standardized computerized administration of the Flanker test (a measure of attention) and the Dimensional Change Card Sort (a measure of cognitive flexibility). Stepwise linear regressions, controlling for possible confounding variables, were used to assess the predictive value of continuous measures of maternal depression and/or anxiety symptoms at each assessment time on the Flanker test and Dimensional Change Card Sort. Posthoc general linear models were used to assess whether maternal depression severity categories (no symptom, mild symptoms, or probable major depressive disorder) were helpful in identifying children at risk. RESULTS: Across all children, after controlling for potential confounds, greater maternal depressive symptoms at weeks 12 to 16 weeks of gestation predicted worse performance on both the Flanker test (ΔR2=0.058; P<.001) and the Dimensional Change Card Sort (ΔR2=0.017; P=.018). Posthoc general linear modeling further demonstrated that the children of mothers meeting the screening criteria for major depression in early pregnancy scored 11.3% lower on the Flanker test and 9.8% lower on the Dimensional Change Card Sort than the children of mothers without maternal depressive symptoms in early pregnancy. Mild depressive symptoms had no significant effect on executive function scores. There was no significant effect of anxiety symptoms or maternal antidepressant use in early pregnancy or pandemic conditions or maternal symptoms in later pregnancy or at the time of child testing on either the Flanker or Dimensional Change Card Sort results. CONCLUSION: This study demonstrated that fetal exposure to maternal major depression, but not milder forms of depression, at 12 to 16 weeks of gestation is associated with impaired executive functioning in the preschool years. Child executive functioning is crucial for school readiness and predicts long-term quality of life. This emphasizes an urgent need to improve the recognition and treatment of maternal major depression, particularly in early pregnancy, to limit its negative effects on the patient and on child cognitive development.

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. Eligible participants were children aged 24 and 54 months. Data were analyzed from June to November 2022. Exposure: COVID-19 pandemic exposure defined as assessment after March 11, 2020. Main Outcome and Measures: Neurodevelopmental assessment using the ASQ-3 (Ages and Stages Questionnaire, Third Edition) and MCHAT-R (Modified Checklist for Autism in Toddlers, Revised) at 24 months of age, and neurocognitive and socioemotional assessment using the National Institutes of Health Toolbox at 54 months of age. Results: A total of 718 children at age 24 months (mean [SD] age, 25.6 [1.7] months; 342 female [47.6%]; 461 White [64.2%]) and 703 at age 54 months (mean [SD] age, 55.4 [2.6] months; 331 female [47.1%]; 487 White [69.3%]) were included. At 24 months of age, 460 participants (232 female [50.4%]) were assessed during the pandemic (March 17, 2020, to May 17, 2022) and 258 (110 female [42.6%]) were assessed prepandemic (April 17, 2018, to March 10, 2020). At 54 months of age, 286 participants (129 female [45.1%]) were assessed from March 14, 2020, to June 6, 2022, and 417 (202 female [48.4%]) were assessed from February 8, 2018, to March 10, 2020. At 24 months of age, pandemic-exposed children had reduced risk of problem-solving difficulties using cutoff scores (odds ratio [OR], 0.33; 95% CI, 0.18-0.62; P = .005) and higher problem-solving (B, 3.93; 95% CI, 2.48 to 5.38; P < .001) compared with nonexposed children. In contrast, pandemic-exposed children had greater risk for personal-social difficulties using cutoff scores (OR, 1.67; 95% CI, 1.09-2.56; P = .02) and continuous scores (B, -1.70; 95% CI, -3.21 to -0.20; P = .02) compared with nonexposed children. At 54 months of age, pandemic-exposed children had higher receptive vocabulary (B, 3.16; 95% CI, 0.13 to 6.19; P = .04), visual memory (B, 5.95; 95% CI, 1.11 to 10.79; P = .02), and overall cognitive performance (B, 3.89; 95% CI, 0.73 to 7.04; P = .02) compared with nonexposed children, with no differences in socioemotional development. Conclusions and Relevance: This cross-sectional study found both positive and negative associations between pandemic exposure and preschool children's cognitive and emotional well-being within a relatively socioeconomically advantaged sample.

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. The purpose of this study was to evaluate trends in unwanted contralateral breast radiation dose to inform risk assessment of second primary cancer in the contralateral breast for long-term survivors of breast cancer. Individually estimated radiation absorbed doses to the four quadrants and areola central area of the contralateral breast were estimated for 2,132 women treated with radiation therapy for local/regional breast cancers at age <55 years diagnosed between 1985 and 2008. The two inner quadrant doses and two outer quadrant doses were averaged. Trends in dose to each of the three areas of the contralateral breast were evaluated in multivariable models. The population impact of reducing contralateral breast dose on the incidence of radiation-associated CBC was assessed by estimating population attributable risk fraction (PAR) in a multivariable model. The median dose to the inner quadrants of the contralateral breast was 1.70 Gy; to the areola, 1.20 Gy; and to the outer quadrants, 0.72 Gy. Ninety-two percent of patients received ≥1 Gy to the inner quadrants. For each calendar year of diagnosis, dose declined significantly for each location, most rapidly for the inner quadrants (0.04 Gy/year). Declines in dose were similar across subgroups defined by age at diagnosis and body mass index. The PAR for CBC due to radiation exposure >1 Gy for women <40 years of age was 17%. Radiation dose-reduction measures have reduced dose to the contralateral breast during breast radiation therapy. Reducing the dose to the contralateral breast to <1 Gy could prevent an estimated 17% of subsequent radiation-associated CBCs for women treated under 40 years of age. These dose estimates inform CBC surveillance for the growing number of breast cancer survivors who received radiation therapy as young women in recent decades. Continued reductions in dose to the contralateral breast could further reduce the incidence of radiation-associated CBC.

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. Fine and Gray regression was used to examine the association between eCRF and breast cancer risk, accounting for both non-breast cancer diagnoses and all-cause mortality as competing risks. Age was used as the time scale. Several different models were produced, including those adjusting for known breast cancer risk factors, and stratified by measures of body fat (body mass index and per cent body fat). RESULTS: Over a median follow-up of 11.0 years there were 529 cases of invasive breast cancer, 1623 cases of non-breast cancer disease and 241 deaths. With adjustment for breast cancer risk factors, high eCRF was associated with a 24% (subdistribution HR (SDHR) 0.76, 95% CI 0.60 to 0.97) lower risk of breast cancer. When stratified by measures of body fat, we found evidence of effect measure modification. Mainly, having high eCRF was only associated with a lower risk of breast cancer among those classified as having overweight/obesity (SDHR 0.33, 95% CI 0.11 to 1.01) or percentage body fat above the 1st quintile (SDHR 0.65, 95% CI 0.45 to 0.94). CONCLUSION: Having higher CRF may be a protective factor against breast cancer in postmenopausal women but only for women with elevated body fat.

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. Pre-diagnosis (n = 4,557) or post-diagnosis (n = 1,600) dietary intake was estimated through a food frequency questionnaire. During a median follow-up time of 11.3 years, 1,265 deaths occurred. Cox proportional hazards models were used to estimate multivariable-adjusted HR and 95% confidence intervals (CI). RESULTS: Women in the highest versus lowest quartile of adherence to the HEI-2015, AHEI, aMED, and DASH indices had a lower risk of all-cause mortality. HR (95% CI) were 0.88 (0.74-1.04; Ptrend = 0.12) for HEI-2015; 0.82 (0.69-0.97; Ptrend = 0.02) for AHEI; 0.73 (0.59-0.92; Ptrend = 0.02) for aMED; and 0.78 (0.65-0.94; Ptrend = 0.006) for DASH. In subgroup analyses, the associations with higher adherence to the four indices were similar for pre- or post-diagnosis dietary intake and were confined to women with a body mass index <25 kg/m2 and women with hormone receptor positive tumors. CONCLUSIONS: Higher adherence to the HEI-2015, AHEI, aMED, and DASH indices was associated with lower mortality among women with breast cancer. IMPACT: Adherence to a healthy diet may improve survival of women with breast cancer.

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. METHODS: We harmonized information collected (e.g., pregnant women's alcohol intake, infants' gestational age and birth weight) from five Canadian pregnancy cohort studies to consolidate a large sample (n = 11,448). Risk factors for any alcohol use during pregnancy, including any alcohol use prior to pregnancy recognition, and binge drinking, were estimated using binomial regressions including fixed effects of pregnancy cohort membership and multiple maternal risk factors. Impacts of alcohol use during pregnancy on birth outcomes (preterm birth and low birth weight for gestational) were also estimated using binomial regression models. RESULTS: In analyses adjusting for multiple risk factors, women's alcohol use during pregnancy, both any use and any binge drinking, was associated with drinking prior to pregnancy, smoking during pregnancy, and white ethnicity. Higher income level was associated with any drinking during pregnancy. Neither drinking during pregnancy nor binge drinking during pregnancy was significantly associated with preterm delivery or low birth weight for gestational age in our sample. CONCLUSIONS: Pooling data across pregnancy cohort studies allowed us to create a large sample of Canadian women and investigate the risk factors for alcohol consumption during pregnancy. We suggest that future pregnancy and birth cohorts should always include questions related to the frequency and amount of alcohol consumed before and during pregnancy that are prospectively harmonized to support data reusability and collaborative research.

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). RESULTS: Girls whose mothers had a pre-pregnancy BMI of ≥25 and gained ≥30 lbs were 57% more likely to experience earlier thelarche than girls whose mothers had a pre-pregnancy BMI of <25 and gained <30 lbs [hazard ratio (HR) = 1.57, 95% CI: 1.16, 2.12]. This association was not mediated by childhood BMI and was similar in girls with and without a BCFH (BCFH: HR = 1.41, 95% CI: 0.87, 2.27; No BCFH: HR = 1.62, 95% CI: 1.10, 2.40). Daughters of women who reported no recreational physical activity during pregnancy were more likely to experience earlier thelarche compared with daughters of physically active women. Birthweight and birth length were not associated with thelarche. CONCLUSION: Earlier thelarche, a breast cancer risk factor, was associated with three potentially modifiable maternal risk factors-pre-pregnancy BMI, gestational weight gain and physical inactivity-in a cohort of girls enriched for BCFH.

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. METHODS: This analysis included data collected throughout pregnancy and delivery from women in the Ontario Birth Study prospective cohort from 2013 to 2019 and from the NIH Toolbox Early Childhood Cognition battery administered to 4-year-old children between 2018 and 2021 (n = 436). The exposure was maternal acetaminophen use and the primary outcome was a cognition composite score. The relationship between exposure and outcome was determined using Poisson regression with a robust error variance. RESULTS: We did not observe any association between maternal acetaminophen intake any time before or during pregnancy and low cognition composite score of offspring. The IRR of suboptimal overall cognition was 1.38 (0.78-2.45), 1.22 (0.67-2.22), 0.80 (0.44-1.47), and 1.56 (0.74-3.29) for maternal use of acetaminophen before, in early, late, or overall pregnancy, respectively. CONCLUSION: Current data do not provide evidence to support a relationship of maternal acetaminophen use during pregnancy with adverse cognitive effects at 4 years. IMPACT: Acetaminophen use during pregnancy may influence the risk of child neurocognitive disorders, but there is conflicting evidence of its relationship to sub-clinical measures of cognitive development such as executive function. The study design allowed us to examine the role of timing of acetaminophen use in its relationship with cognitive development, based on a validated and standardized tablet-administered instrument for children, instead of a teacher or parent report. We did not observe a clear relationship between maternal acetaminophen use at different timepoints during pregnancy and child cognitive development.

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. These preliminary findings suggest that the effect of increasing maternal age on neurodevelopmental risk may be mediated in part by changes in placental protein expression relevant to fetal serotonin metabolism.

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. Three measures of MDA for the unaffected contralateral breast were made at the conventional intensity threshold ("Cumulus") and at two sequentially higher-intensity thresholds ("Altocumulus" and "Cirrocumulus") using the CUMULUS software and mammograms taken up to 3 years prior to the first breast cancer diagnosis. The measures were fitted separately and together in multivariable-adjusted logistic regression models of CBC (252 CBC cases and 271 unilateral breast cancer controls). The strongest association with CBC was MDA defined using the highest intensity threshold, Cirrocumulus (odds ratio per adjusted SD [OPERA] 1.40, 95% CI 1.13-1.73); and the weakest association was MDA defined at the conventional threshold, Cumulus (1.32, 95% CI 1.05-1.66). In a model fitting the three measures together, the association of CBC with Cirrocumulus was unchanged (1.40, 95% CI 0.97-2.05), and the lower brightness measures did not contribute to the CBC model fit. These results suggest that MDA defined at a high-intensity threshold is a better predictor of CBC risk and has the potential to improve CBC risk stratification beyond conventional MDA measures.

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. Prenatal vitamin supplement intake information was collected in early gestation. Child cognition at 4 years was assessed using the NIH Toolbox. Poisson regression was used to investigate associations between PPD and/or prenatal vitamin intake and child cognition. RESULTS: Four hundred and eighteen mother-child dyads were assessed. Moderate-severe PPD experienced during early gestation was associated with reduced cognition (adjusted incidence rate ratio (IRRadj) = 3.71, 95% confidence interval (CI): 1.57-8.77, P = 0.003). Daily intake of prenatal vitamins was not associated with cognition (IRRadj = 1.34, 95% CI: 0.73-2.46, P = 0.34). Upon stratification, the experience of mild-severe PPD with daily intake of prenatal vitamins was associated with higher incident rates of suboptimal cognition compared to children of women with daily prenatal vitamin intake without any episode of PPD (IRRadj = 2.88, 95% CI: 1.1-7.4). CONCLUSIONS: Moderate-severe PPD in early pregnancy is associated with poor cognition in children and daily intake of prenatal vitamin did not ameliorate this association. IMPACT: Our findings expand on existing literature by highlighting that exposure to prenatal psychological distress (PPD), in moderate-to-severe form, in the early stages of pregnancy, can have detrimental effects on the offspring's cognitive development at 4 years. Overall, prenatal vitamin intake did not ameliorate the effects of PPD. Early screening and treatment of prenatal maternal mental illness is crucial.

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. We hypothesized increased depression and anxiety scores in women during pregnancy and after birth in the pandemic at all time points. STUDY DESIGN: Participants were enrolled in the Ontario Birth Study, a pregnancy cohort embedded in clinical care at Mount Sinai Hospital, Toronto, Canada. Perinatal depression and anxiety were assessed using the 2-Item Patient Health Questionnaire and 2-Item Generalized Anxiety Disorder Questionnaire in early pregnancy, whereas the Edinburgh Postnatal Depression Scale and 2-Item Generalized Anxiety Disorder Questionnaire were used in late pregnancy and after birth. Logistic regression models were created to examine the association of the pandemic with clinically elevated mental health scores in the prepandemic group vs pandemic group while adjusting for covariates. RESULTS: A total of 1159 survey responses from 649 participants between March 1, 2019, and February 28, 2021, were used to conduct this study. Participants were assessed in early pregnancy (n=416), in late pregnancy (n=373), and after birth (n=370). Responses received on or before February 29, 2020, were considered the "prepandemic" responses, whereas responses after the aforementioned date were considered the "pandemic" responses. Mean rank scores of depression and anxiety were significantly higher in the pandemic group (P=.02 and P=.003, respectively) in the postpartum period. There was no significant association between pandemic time and antenatal scores. However, postnatally, mothers were 2.6 times more likely to score ≥13 on the Edinburgh Postnatal Depression Scale during the pandemic than before the pandemic (95% confidence interval, 1.2-5.7; P=.02). Adjustment for ethnicity and income strengthened this association as the odds ratio increased to 3.3 (95% confidence interval, 1.4-8.0; P=.007). CONCLUSION: Pandemic-associated increases in depression and anxiety scores were confined to the postpartum period, highlighting a need for increased screening and interventions for perinatal mood and anxiety disorders postnatally as this pandemic continues.

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. Using constrained splines, we interpolated individual growth curves and then predicted BMI at ages 2, 4, 6, 8 and 9 years for 591 girls. We defined age at BMI rebound as the age at the lowest BMI between ages 2 and 8 years and assessed its association with onset of thelarche, pubarche and menarche using Weibull survival models. RESULTS: The median age at BMI rebound was 5.3 years (interquartile range: 3.6-6.7 years). A 1-year increase in age at BMI rebound was associated with delayed thelarche (HR = 0.90; 95% CI = 0.83-0.97) and menarche (HR = 0.86; 95% CI = 0.79-0.94). The magnitude of these associations remained after adjusting for weight between birth and 2 years, was stronger after adjusting for BMI at age 9, and was stronger in a subset of girls with clinically assessed breast development. CONCLUSIONS: Earlier BMI rebound is associated with earlier pubertal timing. Our observation that BMI rebound may be a driver of pubertal timing in girls with and without a family history of breast cancer provides insight into how growth and pubertal timing are associated with breast cancer risk.

Smoking, Radiation Therapy, and Contralateral Breast Cancer Risk in Young Women.

Evidence is mounting that cigarette smoking contributes to second primary contralateral breast cancer (CBC) risk. Whether radiation therapy (RT) interacts with smoking to modify this risk is unknown. In this multicenter, individually matched, case-control study, we examined the association between RT, smoking, and CBC risk. The study included 1521 CBC cases and 2212 controls with unilateral breast cancer, all diagnosed with first invasive breast cancer between 1985 and 2008 aged younger than 55 years. Absorbed radiation doses to contralateral breast regions were estimated with thermoluminescent dosimeters in tissue-equivalent anthropomorphic phantoms, and smoking history was collected by interview. Rate ratios (RRs) and 95% confidence intervals (CIs) for CBC risk were estimated by multivariable conditional logistic regression. There was no interaction between any measure of smoking with RT to increase CBC risk (eg, the interaction of continuous RT dose with smoking at first breast cancer diagnosis [ever/never]: RR = 1.00, 95% CI = 0.89 to 1.14; continuous RT dose with years smoked: RR = 1.00, 95% CI = 0.99 to 1.01; and continuous RT dose with lifetime pack-years: RR = 1.00, 95% CI = 0.99 to 1.01). There was no evidence that RT further increased CBC risk in young women with first primary breast cancer who were current smokers or had smoking history.

Recreational Physical Activity and Outcomes After Breast Cancer in Women at High Familial Risk.

Background: Recreational physical activity (RPA) is associated with improved survival after breast cancer (BC) in average-risk women, but evidence is limited for women who are at increased familial risk because of a BC family history or BRCA1 and BRCA2 pathogenic variants (BRCA1/2 PVs). Methods: We estimated associations of RPA (self-reported average hours per week within 3 years of BC diagnosis) with all-cause mortality and second BC events (recurrence or new primary) after first invasive BC in women in the Prospective Family Study Cohort (n = 4610, diagnosed 1993-2011, aged 22-79 years at diagnosis). We fitted Cox proportional hazards regression models adjusted for age at diagnosis, demographics, and lifestyle factors. We tested for multiplicative interactions (Wald test statistic for cross-product terms) and additive interactions (relative excess risk due to interaction) by age at diagnosis, body mass index, estrogen receptor status, stage at diagnosis, BRCA1/2 PVs, and familial risk score estimated from multigenerational pedigree data. Statistical tests were 2-sided. Results: We observed 1212 deaths and 473 second BC events over a median follow-up from study enrollment of 11.0 and 10.5 years, respectively. After adjusting for covariates, RPA (any vs none) was associated with lower all-cause mortality of 16.1% (95% confidence interval [CI] = 2.4% to 27.9%) overall, 11.8% (95% CI = -3.6% to 24.9%) in women without BRCA1/2 PVs, and 47.5% (95% CI = 17.4% to 66.6%) in women with BRCA1/2 PVs (RPA*BRCA1/2 multiplicative interaction P = .005; relative excess risk due to interaction = 0.87, 95% CI = 0.01 to 1.74). RPA was not associated with risk of second BC events. Conclusion: Findings support that RPA is associated with lower all-cause mortality in women with BC, particularly in women with BRCA1/2 PVs.

Mammographic texture features associated with contralateral breast cancer in the WECARE Study.

To evaluate whether mammographic texture features were associated with second primary contralateral breast cancer (CBC) risk, we created a "texture risk score" using pre-treatment mammograms in a case-control study of 212 women with CBC and 223 controls with unilateral breast cancer. The texture risk score was associated with CBC (odds per adjusted standard deviation = 1.25, 95% CI 1.01-1.56) after adjustment for mammographic percent density and confounders. These results support the potential of texture features for CBC risk assessment of breast cancer survivors.

Coronary Artery Disease in Young Women After Radiation Therapy for Breast Cancer: The WECARE Study.

BACKGROUND: Radiation therapy (RT) for breast cancer increases risk of coronary artery disease (CAD). Women treated for left- vs right-sided breast cancer receive greater heart radiation exposure, which may further increase this risk. The risk of radiation-associated CAD specifically among younger breast cancer survivors is not well defined. OBJECTIVES: The purpose of this study was to report CAD risk among participants in the Women's Environmental Cancer and Radiation Epidemiology Study. METHODS: A total of 1,583 women who were <55 years of age when diagnosed with breast cancer between 1985 and 2008 completed a cardiovascular health questionnaire. Risk of radiation-associated CAD was evaluated by comparing women treated with left-sided RT with women treated with right-sided RT using multivariable Cox proportional hazards models. Effect modification by treatment and cardiovascular risk factors was examined. RESULTS: In total, 517 women who did not receive RT and 94 women who had a pre-existing cardiovascular disease diagnosis were excluded, leaving 972 women eligible for analysis. Their median follow-up time was 14 years (range 1-29 years). The 27.5-year cumulative incidences of CAD for women receiving left- vs right-sided RT were 10.5% and 5.8%, respectively (P = 0.010). The corresponding HR of CAD for left- vs right-sided RT in the multivariable Cox model was 2.5 (95% CI: 1.3-4.7). There was no statistically significant effect modification by any factor evaluated. CONCLUSIONS: Young women treated with RT for left-sided breast cancer had over twice the risk of CAD compared with women treated with RT for right-sided breast cancer. Laterality of RT is independently associated with an increased risk of CAD and should be considered in survivorship care of younger breast cancer patients.