ASPO Abstracts

Authors: Kehm RD, Lilge L, Walter EJ, Zeinomar N, Hervstman J, Miller R, Tehranifar P, Terry MB

Category: Lifestyles Behavior, Energy Balance & Chemoprevention
Conference Year: 2020

Abstract Body:
Purpose: Recreational physical activity (RPA) and body mass index (BMI) are independently associated with breast cancer risk, but less is known about associations with breast tissue composition over the lifecourse. We previously found an association for RPA and BMI with breast tissue composition in a cohort of adolescent girls. Here we examine associations of RPA and BMI with breast tissue composition of mothers in the cohort. Methods: 212 African American and Hispanic women living in the South Bronx or Northern Manhattan participated in Columbia’s Breast Cancer and the Environment Research Project (BCERP) Study (mean age=41.8±5.3 years; 94% premenopausal). Women completed a clinic visit during which we measured breast tissue composition using optical spectroscopy (OS), a non-invasive tool that provides both functional and structural information. We used principal component (PC) analysis to reduce spectral data by generating 7 PC scores for each participant averaged over both breasts. We measured height and weight at the clinic visit, and women reported by questionnaire average hours per week of moderate and strenuous RPA during the past year. We converted hours per week of moderate and strenuous RPA to total metabolic equivalents (METs). We used multivariable linear regression to examine the association of RPA and BMI with the first 5 OS PCs, which explained 99.7% of the sample variation. We modeled RPA and BMI as both continuous and categorical measures, and we adjusted for age and ethnicity. Results: 23% percent of women reported no RPA in the past year. Women reported an average of 17 METs per week in the past year (range: 0-111 METs). Average BMI in the sample was 30.8 kg/m2 (range: 18.2-57.1 kg/m2), and 80% of women had a BMI ≥25 kg/m2. BMI was not correlated with RPA (ρ=-0.01) in our sample. BMI was significantly associated with 2 of the 5 OS PCs (p<0.05). RPA was not significantly associated with OS PCs in models unadjusted or adjusted for BMI, or stratified by BMI (all p>0.05). Conclusions: Our preliminary results suggest that BMI may be associated with breast tissue composition in African American and Hispanic women, independent of RPA. Unlike our findings for adolescent girls, RPA was not associated with breast tissue composition of mothers.

Keywords: physical activity, body mass index, breast tissue composition, optical spectroscopy

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