Abstract B05: Randomized pilot study of Project BALANCE: a weight gain prevention intervention for breast cancer patients receiving neoadjuvant chemotherapy

Background: Weight gain is a common problem after breast cancer diagnosis and treatment, particularly for women who receive chemotherapy. The weight gain has negative effects on quality of life, increases risk for chronic disease, and may increase risk of breast cancer recurrence. This pilot study tested a behavioral weight gain prevention intervention on weight, waist circumference, and biomarkers related to breast cancer prognosis (sex hormone binding globulin [SHBG], adiponectin, and leptin). Methods: Thirty-eight breast cancer patients receiving neoadjuvant chemotherapy were randomized to the weight gain prevention intervention or usual care. The intervention focused on exercise (resistance training, aerobic) and eating a low energy dense diet. Participants received 20 sessions during chemotherapy (14 in person, 6 by telephone) and 9 sessions after surgery (3 in person, 6 by telephone). They completed assessments of weight and waist circumference at baseline (T0), mid-chemotherapy (T1), post-chemotherapy (T2), post surgical recovery (T3), after the post-surgical intervention (T4). Serum was collected at T0, T2, and T3 and SHBG, adiponectin, and leptin was assayed by ELISA. Differences between participants in the intervention and usual care groups for weight, waist circumference, and biomarkers were assessed using linear mixed models. All analyses were controlled for baseline values. Missing observations were imputed by worst observation carried forward. We conducted both an intent-to-treat (all participants) and a per protocol analysis where intervention group participants were included if they completed at least 50% of the intervention sessions. Results: In the intent to treat analysis, the intervention group participants weighed less at T1-T4 (mean difference = 1.12 kg, p = .2225). In the per protocol analysis the mean difference of 1.6 kg was statistically significant (p=.0499). Waist circumference was lower at T1-T4 in the intervention group in both the intent-to-treat analysis (mean difference = 2.8 cm, p=.0354) and the per protocol analysis (mean difference = 3.7 cm, p=.0122). Levels of natural log transformed SHBG were higher for the intervention group at T2-T3; the difference neared significance (intent-to-treat: p=.0914; per protocol analysis: p=.0506), but there was no significant difference between the groups in adiponectin or leptin levels. However, all three biomarkers were significantly correlated with weight, BMI and waist circumference in the expected direction at T0, T2, and T3, with the exception of SHBG at T3, which was significantly correlated with weight only. Conclusion: A diet and exercise intervention delivered during and after chemotherapy can promote weight loss in breast cancer patients. Given the associations between body composition and prognostic biomarkers, the Project BALANCE intervention could be investigated for its effects on prognosis. Citation Format: Karen Basen-Engquist, James L. Murray, III, Abenaa Brewster, Susan M. Schembre, Jaejoon Song, Angelica Gutierrez-Barrera, Banu Arun. Randomized pilot study of Project BALANCE: a weight gain prevention intervention for breast cancer patients receiving neoadjuvant chemotherapy. [abstract]. In: Proceedings of the Thirteenth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2014 Sep 27-Oct 1; New Orleans, LA. Philadelphia (PA): AACR; Can Prev Res 2015;8(10 Suppl): Abstract nr B05.