Childhood and teenage physical activity and breast cancer risk.

ABSTRACT:

Purpose

Adult physical activity is associated with reduced breast cancer risk, but few studies have evaluated activity before adulthood. Early life may be an important period because of rapid breast development and hormonal changes. This study contributes new information by examining childhood (ages 5-12) and teenage (ages 13-19) activity separately and overall.

Methods

The Sister Study is a cohort of 50,884 women aged 35-74. Women reported age 5-19 sports/exercise activities and age 10 and 16 unstructured activities. Both hours and MET-hours of activity were considered in association with breast cancer overall, by ER status, and by menopausal status. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated with Cox proportional hazards models.

Results

2

SUBMITTER: Niehoff NM 

PROVIDER: S-EPMC5553118 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature