Abstract 2227: Physical activity at breast cancer diagnosis and incident cardiovascular disease in the Pathways Study
Authors: Kresovich Jacob K. , Richards Alicia R. , Ergas Isaac J. , Laurent Cecile A. , Cannioto Rikki , Rana Jamal S. , Roh Janise M. , Thomsen Catherine , Shariff-Marco Salma , Rillamas-Sun Eileen , Cheng Richard K. , Yao Song , Ambrosone Christine B. , Kushi Lawrence H. , Greenlee Heather , Kwan Marilyn L. 
Published: March 2024

Abstract
Background: Breast cancer survivors are at increased risk of cardiovascular disease (CVD) compared to women without a history of breast cancer. Although cardiotoxic cancer treatments influence these risks, lifestyles that are associated with both breast cancer and CVD also contribute. With the number of breast cancer survivors expected to increase, a growing need exists to identify modifiable risk factors that protect against the development of CVD after diagnosis. Physical activity at breast cancer diagnosis is associated with lower cancer recurrence and mortality risk. However, associations between physical activity at diagnosis and incident CVD have yet to be investigated in detail.
Methods: The Pathways Study is a prospective cohort study of 4,504 women who were members of Kaiser Permanente Northern California (KPNC) when diagnosed with first primary invasive breast cancer between 2005 and 2013. At enrollment, women self-reported their frequency, duration, and intensity of physical activities during the previous six months using the Arizona Activity Frequency Questionnaire. This information was used to dichotomize the women’s physical activity levels by the CDC’s Physical Activity Guidelines for Americans (≥ 150 minutes of moderate-to-vigorous physical activity per week vs less). CVD events were obtained from electronic health records as part of the Pathways Heart Study and were defined as post-diagnostic incidence of ischemic heart disease, heart failure, cardiomyopathy, and stroke. Deaths were documented through several sources, including the National Death Index. Women were followed until the first of disenrollment from the KPNC health plan, death, or December 31, 2021. Competing risk Cox regression models were used to estimate associations between meeting CDC physical activity guidelines and CVD.
Results: In this cohort of breast cancer survivors, women who self-reported meeting physical activity guidelines at diagnosis experienced lower rates of post-diagnostic CVD events (8.6% vs 13.1%). After adjustment for socio-demographic factors, meeting physical activity guidelines remained associated with lower risk of CVD (HR: 0.78, 95% CI: 0.61, 0.98); this association appeared to be driven by reduced risk of heart failure (HR: 0.68, 95% CI: 0.50, 0.93) and cardiomyopathy (HR: 0.51, 95% CI: 0.28, 0.92). Approximately 15% of the CVD risk reduction in Pathways Study participants can be attributed to meeting physical activity guidelines (population attributable risk percent: 14.5%, 95% CI: 8%, 21%).
Conclusions: Compared to women who did not meet CDC physical activity guidelines, women who reported meeting guidelines near the time of their breast cancer diagnosis had decreased risk of future CVD, including heart failure and cardiomyopathy. Future studies investigating changes in post-diagnostic physical activity patterns and CVD risk are warranted.
Citation Format: Jacob K. Kresovich, Alicia R. Richards, Isaac J. Ergas, Cecile A. Laurent, Rikki Cannioto, Jamal S. Rana, Janise M. Roh, Catherine Thomsen, Salma Shariff-Marco, Eileen Rillamas-Sun, Richard K. Cheng, Song Yao, Christine B. Ambrosone, Lawrence H. Kushi, Heather Greenlee, Marilyn L. Kwan. Physical activity at breast cancer diagnosis and incident cardiovascular disease in the Pathways Study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2227.