# Physical Activity Patterns According to Demographic, Social, and Clinical Correlates Among Breast Cancer Survivors

## TL;DR

This study examines how physical activity changes over time in breast cancer survivors and finds that factors like income and BMI influence activity levels.

## Contribution

The study provides new insights into racial and socioeconomic disparities in physical activity patterns among breast cancer survivors.

## Key findings

- MVPA levels dropped after diagnosis but rebounded by 18 months.
- Higher income and lower BMI were linked to increased MVPA at 18 months.
- Social and clinical factors contribute to disparities in physical activity among survivors.

## Abstract

Moderate to vigorous physical activity (MVPA) after breast cancer diagnosis is associated with improved survivorship. However, differences in MVPA by race among breast cancer survivors are not well described in population‐based studies.

We analyzed data from Carolina Breast Cancer Study Phase 3 (n = 2994, 50% Black) participants to evaluate the trajectory of MVPA from pre‐diagnosis to 18‐month post‐diagnosis. Participants self‐reported MVPA at baseline (pre‐diagnosis) and 6‐ and 18‐month post‐diagnosis and were classified as having any MVPA (> 0 min/week) or no MVPA. Associations between MVPA and demographic, social, and clinical variables were estimated using multivariable logistic regression.

At baseline, 84.0% of participants reported any MVPA pre‐diagnosis, which dropped to 55.4% at 6‐month post‐diagnosis, then rebounded to 85.1% by 18‐month post‐diagnosis. Among those who had no MVPA pre‐diagnosis, 32.5% and 71.0% became active at 6‐ and 18‐month post‐diagnosis, respectively. Higher income [adjusted odds ratio (aOR) = 1.33, 95% confidence interval (CI) (1.02, 1.74) > $30K vs. < 15K], lower body mass index [aOR = 1.30, 95% CI (1.00, 1.73) < 25 vs. > 30], low area deprivation [aOR = 1.35, 95% CI (1.08, 1.67) vs. high], high area assets [aOR = 1.54, 95% CI (1.23, 1.93) vs. low], and stage I breast cancer [aOR = 1.72, 95% CI (1.22, 2.43) vs. 3 or 4] were associated with any MVPA at 18‐month post‐diagnosis.

We identified several demographic and social correlates of any MVPA at 18‐month post‐diagnosis, and together with established clinical correlates (such as late disease), these factors may contribute to breast cancer disparities.