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

2023

272-283

02/2023

1464-3685

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.

10.1093/ije/dyac108

Int J Epidemiol

35613015

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

2022

05/2022

1464-3685

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.

10.1093/ije/dyac108

Int J Epidemiol

35613015

Common Childhood Viruses and Pubertal Timing: The LEGACY Girls Study.

2020

2020 Oct 31

1476-6256

<p>Earlier pubertal development is only partially explained by childhood body mass index (BMI); the role of other factors like childhood infections is less understood. Using data from the LEGACY Girls Study (2011 - 2016), we prospectively examined the associations between childhood viral infections (Cytomegalovirus (CMV), Epstein Barr Virus (EBV), Herpes Simplex Virus 1 (HSV1), HSV2 and pubertal timing. We measured exposures based on seropositivity in pre-menarcheal girls (n=490). Breast and pubic hair development were classified based on mother-reported Tanner Stage (TS: TS2+ compared with TS1), adjusting for age, BMI, and sociodemographic factors. The average age at first blood draw was 9.8 years (Stdev=1.9 years). The prevalences were 31% CMV+, 37% EBV+, 14% HSV1+, 0.4% HSV2+, and 16% for both CMV+/EBV+. CMV+ infection without co-infection was associated with developing breasts an average of 7 months earlier (Hazard Ratio (HR)=2.12, 95% CI 1.32, 3.40). CMV+ infection without co-infection and HSV1+ and/or HSV2+ infection were associated with developing pubic hair 9 months later (HR 0.41, 95% CI 0.24, 0.71, HR 0.42, 95% CI 0.22, 0.81, respectively). Infection was not associated with menarche. If replicated in larger cohorts with blood collection prior to any breast development, this study supports that childhood infections may play a role in altering pubertal timing.</p>

10.1093/aje/kwaa240

Am J Epidemiol

33128063

Psychosocial Adjustment and Perceived Risk Among Adolescent Girls From Families With BRCA1/2 or Breast Cancer History.

2016

2016 Aug 22

1527-7755

<p><strong>PURPOSE: </strong>To evaluate the impact of breast cancer family history and maternal BRCA1/2 mutation on the psychosocial adjustment and perceived risk in girls age 11 to 19 years old.</p>

<p><strong>MATERIALS AND METHODS: </strong>Girls age 11 to 19 years old with one or more relatives with breast cancer or a familial BRCA1/2 mutation (breast cancer family history [BCFH] positive, n = 208; n = 69 with BRCA1/2-positive mother), peers (BCFH negative, n = 112), and their mothers completed assessments of psychosocial adjustment, breast cancer-specific distress, and perceived risk of breast cancer.</p>

<p><strong>RESULTS: </strong>General psychosocial adjustment did not differ significantly between BCFH-positive and BCFH-negative girls, either by self-report or mother report, except for higher self-esteem among BCFH-positive girls (P = .01). BCFH-positive girls had higher breast cancer-specific distress than BCFH-negative girls (P &lt; .001), but girls from BRCA1/2-positive families did not differ from other BCFH-positive peers. BCFH-positive girls were more likely to report themselves at increased self-risk for breast cancer in adulthood than BCFH-negative peers (74% v 33%, respectively; P ≤ .001). Girls from BRCA1/2-positive families were more likely than other BCFH-positive and BCFH-negative peers to report themselves at increased risk (P &lt; .001). In all groups, perceived risk of breast cancer was associated with older age. Higher breast cancer-specific distress among adolescent girls was associated with higher self-perceived risk of breast cancer and higher maternal breast cancer-specific distress.</p>

<p><strong>CONCLUSION: </strong>Adolescent girls from BRCA1/2-positive and breast cancer families have higher self-esteem and do not have poorer psychosocial adjustment than peers. However, they do experience greater breast cancer-specific distress and perceived risk of breast cancer, particularly among older girls. Understanding the impact is important to optimize responses to growing up in families at familial and genetic risk for breast cancer, particularly given the debate over the genetic testing of children for cancer susceptibility in adulthood.</p>

10.1200/JCO.2015.66.3450

J. Clin. Oncol.

27551110

The LEGACY Girls Study: Growth and Development in the Context of Breast Cancer Family History.

2016

438-48

2016 May

1531-5487

<p><strong>BACKGROUND: </strong>Although the timing of pubertal milestones has been associated with breast cancer risk, few studies of girls' development include girls at increased breast cancer risk due to their family history.</p>

<p><strong>METHODS: </strong>The Lessons in Epidemiology and Genetics of Adult Cancer from Youth (LEGACY) Girls Study was initiated in 2011 in the USA and Canada to assess the relation between early life exposures and intermediate markers of breast cancer risk (e.g., pubertal development, breast tissue characteristics) and to investigate psychosocial well being and health behaviors in the context of family history. We describe the methods used to establish and follow a cohort of 1,040 girls ages 6-13 years at baseline, half with a breast cancer family history, and the collection of questionnaire data (family history, early life exposures, growth and development, psychosocial and behavioral), anthropometry, biospecimens, and breast tissue characteristics using optical spectroscopy.</p>

<p><strong>RESULTS: </strong>During this initial 5-year phase of the study, follow-up visits are conducted every 6 months for repeated data and biospecimen collection. Participation in baseline components was high (98% for urine, 97.5% for blood or saliva, and 98% for anthropometry). At enrollment, 77% of girls were premenarcheal and 49% were at breast Tanner stage T1.</p>

<p><strong>CONCLUSIONS: </strong>This study design allows thorough examination of events affecting girls' growth and development and how they differ across the spectrum of breast cancer risk. A better understanding of early life breast cancer risk factors will be essential to enhance prevention across the lifespan for those with and without a family history of the disease.</p>

10.1097/EDE.0000000000000456

Epidemiology

26829160