IMETX (Individualized Metabolic RX): An environmental intervention to increase energy expenditure in breast cancer survivors.

Abstract

e23060 Background: Despite survival and quality of life benefits associated with physical activity (PA), many breast cancer survivors remain inactive. Effective, sustainable PA interventions must account for individual differences in capability, motivation, and environment. iMETX evaluated the feasibility, mechanics, and efficacy of delivering an individualized, dynamic intervention to increase energetic capacity and energy expenditure in breast cancer survivors. Methods: Stage 0-III breast cancer pts who had completed primary treatment were enrolled. Baseline PA patterns were collected using a wearable GPS/accelerometer for 4 weeks pre- intervention. Detailed movement data collection continued throughout the 12- week intervention, during which pts received tailored PA “prescriptions” every 1-3 days from an interactive web application, adjusted based on individual capability and environment to achieve pre- determined energy endpoints. Baseline and post- intervention, energetic capacity was assessed by power generation using a stationary bicycle protocol feasible in the clinic setting over a range of physical capabilities. Body composition by DEXA and quality of life questionnaires were collected. Results: 56 of 57 enrolled pts completed the intervention (98%). Median age was 60 (range 38 – 82), and pts were an average of 5.25 yrs from diagnosis (range 0.5 – 21 yrs). In the total population, energetic capacity (Watts/kg lean mass) increased significantly from 1.75 to 1.99 W/kg (p < 0.01) post- intervention. Separated by baseline energetic capacity, the lowest performing tertile improved significantly (0.76 to 1.12 W/kg, p < 0.01), while the highest performing tertile did not (2.75 to 2.96 W/kg, p = 0.30). Physical and functional well-being also improved (FACT-B TOI, pre: 72.26, post: 74.66, p = 0.02). Conclusions: iMETx is a feasible PA intervention with high adherence rates. Individualized PA prescriptions allowing pts to move in their typical environment resulted in improved energetic capacity and well- being. Results were particularly significant in those with the lowest baseline energetic capacity, a population most in need of effective and accessible PA interventions. Clinical trial information: NCT03158519.