Abstract P4-14-01: POWER-remote: A randomized study evaluating the effect of a remote-based weight loss program in women with early stage breast cancer

Abstract

Abstract Background: The majority of women diagnosed with breast cancer are overweight or obese, and gain weight after diagnosis. The Practice-based Opportunities for Weight Reduction (POWER) study reported that, in an obese population with cardiovascular risk factors, a scalable remote weight loss intervention with web support was equally effective to an in-person intervention (Appel NEJM 2011). We adapted the remote intervention for breast cancer survivors. Methods: We conducted a phase II single-blind trial in which women with stage 0-III breast cancer and a BMI ≥25 were randomized to a remotely-delivered weight loss intervention with a study specific website (POWER-remote) or to self-directed weight loss. Participants were stratified by menopausal status and concomitant hormone therapy use. Weight was assessed at baseline, 6 and 12 months. The primary objective was to compare the proportion of women who lost ≥5% of their baseline body weight after 6 months in the POWER-remote and the self-directed arms. A sample size of 80 patients yielded approximately 93.6% power to detect a difference in weight loss response of 19.0% in the self-directed arm and 38.2% in the POWER-remote arm with a one-sided type I error of 10%. We obtained blood samples for correlative studies including inflammatory biomarkers and assessment of telomere length at baseline and 6 months. Results: From 2013-2015 we enrolled 96 women; 84 were evaluable for the primary analysis. Both cohorts had similar baseline characteristics including menopausal status, race (77% Caucasian and 20% African American in entire cohort), and BMI (average mean 32 kg/m2). The majority (93%) of patients received endocrine therapy, and 55% had completed chemotherapy. At 6 months 43.1% (95% CI 29.3–57.8) of women randomized to POWER-remote had lost ≥5% of their baseline body weight, compared to 11.1% (95% CI 3.7–24.1) in the self-directed arm, p<0.001. A significant difference continued at 12 months, and was observed in all subgroups (Table 1). Biomarker analysis will be presented at the meeting. Table 1. Proportion of patients achieving ≥5% weight loss after 6 and 12 months POWER-remotePOWER-remoteSelf-DirectedSelf-Directed n% [95% CI]n% [95% CI]p-valueInteraction p-value for heterogeneity of treatment effectLost >=5% of baseline weight at 6 months All patients4343.1 [29.3, 57.8]4111.1 [3.7, 24.1]<0.001 Endocrine therapy3545 [29.3, 61.5]3211.1 [3.1, 26.1]< 0.0010.96No endocrine therapy836.4 [10.9, 69.2]911.1 [0.3, 48.2]0.11 Chemotherapy2126.9 [11.6, 47.8]253.7 [0.1, 19]0.010.64No chemotherapy2260 [38.7, 78.9]1622.2 [6.4, 47.6]0.01 Lost >=5% of baseline weight at 12 months All patients3031.4 [19.1, 45.9]3113.3 [5.1, 26.8]0.006 Endocrine therapy2632.5 [18.6, 49.1]2616.7 [6.4, 32.8]0.040.99No endocrine therapy427.3 [6, 61]50 [0, 33.6]0.05 Chemotherapy1119.2 [6.6, 39.4]167.4 [0.9, 24.3]0.070.72No chemotherapy1944 [24.4, 65.1]1522.2 [6.4, 47.6]0.07 Conclusions: Sustained weight loss over 1 year is feasible in breast cancer survivors who undergo a remotely delivered weight loss intervention. Weight loss was observed irrespective of endocrine therapy or chemotherapy. These data will be used to design a new trial with a physical activity component. Citation Format: Santa-Maria CA, Coughlin J, Blackford A, Carpenter A, Dalcin A, Huang C-Y, Luber B, Schreyer C, Armanios M, Sharma D, Chaudhry M, Jerome GJ, Snyder C, Appel L, Stearns V. POWER-remote: A randomized study evaluating the effect of a remote-based weight loss program in women with early stage breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-14-01.