Background: Body composition, adipose distribution, and fitness are likely superior to BMI alone in predicting outcomes in obese breast cancer survivors. Visceral adipose tissue (VAT) is thought to be disproportionately responsible for the metabolic and inflammatory changes linking obesity and breast cancer recurrence.

Purpose: Feasibility of achievement of high volume moderate-to-vigorous physical activity (MVPA) and its effect on body composition including VAT and other risk biomarkers in older sedentary, obese breast cancer survivors participating in a behavioral weight loss intervention.

Methods: Modest caloric restriction (350-500 kcal per day) was combined with a study provided YMCA membership and twice weekly personal trainer sessions. MVPA (40-80% of heart rate reserve in older women) was assessed by Garmin Vivoactive smart watches linked to GarminConnect. Total activity was escalated from 100 minutes week 1 to a total of 300 minutes per week by week 9 with a goal of > 200 min/wk as MVPA. Women were evaluated pre- and post-intervention for peak oxygen consumption (VO2peak), body composition by dual energy x-ray absorptiometry (GE Lunar iDXA), and serum levels of adipokines, cytokines, and hormones.

Results: 18 breast cancer survivors were enrolled and completed the 3 months of the behavioral weight loss intervention which included the YMCA membership and twice weekly personal trainer. Median age was 60, 11 had received prior chemotherapy, and 13 were currently taking aromatase inhibitors. Median (and range) baseline anthropomorphic values were BMI 37 (31-43) kg/m2, total mass 95 (76-125) kg, total fat 46 (34-66) kg, and VAT 1.7 (1.0-3.0) kg. All but one had a baseline VAT > 1.17 kg, consistent with elevated risk of metabolic syndrome. 17/18 achieved at least 150 min/wk of MVPA, with a median of 176 (range 55-291) min/wk for weeks 9-12. Fitness measured as VO2peak increased from 18.9 (13.7-25.3) to 21.1 (17.1-31.4) ml/kg/min (p=0.0003; Wilcoxon signed rank test). At 3 months, significant reductions were observed for total mass (median 7%), fat mass (median 13%), and VAT (median 20%, range 1-41%)(p<0.0003); as well as serum leptin, insulin, and leptin: adiponectin ratio (p<0.01). A strong correlation was observed between week 9-12 MVPA and leptin: adiponectin ratio (p=0.001) with more modest correlations between week 9-12 MVPA and VAT loss (p=0.043), and leptin: adiponectin ratio and VAT loss (p=0.013).

Conclusion: High volume moderate-to-vigorous physical activity can be achieved by older, sedentary, obese breast cancer survivors; and this translates to favorable modulation of body composition including VAT measures and serum risk biomarkers.

Citation Format: Carol J. Fabian, Jennifer R. Klemp, Jeffrey M. Burns, Eric D. Vidoni, Lauren Nye, Christie A. Befort, Jill M. Hamilton-Reeves, Debra K. Sullivan, Teresa A. Phillips, Stephen D. Hursting, Bruce F. Kimler. Moderate to vigorous physical activity reduces visceral adipose tissue in obese breast cancer survivors undergoing a weight loss intervention [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2425.