Abstract 15439: Longitudinal Assessment of Racial Differences in Exercise Capacity After Breast Cancer Treatment: WF-97415

Abstract

Introduction: Breast cancer (BC) treatment toxicity contributes to elevated rates of cardiovascular morbidities, such as reduced exercise capacity, a risk factor for long-term cardiovascular disease (CVD) and mortality. Past studies have shown that Black women experience greater cardiotoxicity after BC treatment than white women. No studies have investigated racial differences in exercise capacity. The lack of longitudinal data leaves uncertainty as to whether greater declines in exercise capacity are experienced by Black BC survivors. Methods: This cohort was comprised of 236 women with stage I-III BC (80% white; 20% Black) and 130 cancer-free controls in the UPBEAT (NCT02791581) and DETECT (NCT01719562) studies. Submaximal exercise capacity was obtained via 6-Minute Walk Distance (6MWD, meters [m]) at baseline (pre-treatment) and 3 months. Linear regression was used to examine associations of race with baseline 6MWD and changes in 6MWD. Results: Mean age [SD] of BC survivors was 55.7 [10.9] years. Mean [SD] total meters walked pre-treatment was lower in Black women with BC (423 m [81.0]) than white women with BC (475 m [87.7]; p=0.01), and lower than Black women without BC (471 m [76.9]; p=0.07). Black BC survivors experienced a greater mean decline from baseline to 3-months in 6MWD (30 m [68.5]) than white BC survivors (21.7 m [86.6]; Table 1; p=0.02) or Black women without BC (9.2 m [67.3]; p=0.001), translating to a mean difference of 60 m between Black and white BC survivors during BC treatment. Conclusions: This is the first study to suggest racial differences in submaximal exercise capacity during BC treatment. Black BC survivors experienced a greater reduction in exercise capacity than white BC survivors after cancer treatment as early as 3-months post-diagnosis. This clinically-meaningful difference in exercise capacity warrants further investigation, particularly to determine interventions to reverse the loss of exercise capacity.