Weight Reduction Intervention for Breast Cancer Survivors

Background: Overweight or obesity is an established negative prognostic factor in both premenopausal and postmenopausal breast cancer. Adverse effects of adiposity on prognosis may be explained by effects on gonadal hormones, insulin, insulin-like growth factor (IGF)-I, IGF binding proteins (IGFBPs), and leptin. Objective/Hypothesis: This study tests whether a multifaceted approach can achieve weight loss and maintenance in overweight or obese breast cancer survivors. The intervention incorporates cognitive-behavioral therapy, increased physical activity, diet modification, and strategies to improve body image and self-acceptance. This approach and intervention were developed and pilot-tested with support from a previous peer-reviewed grant. Weight change from baseline to one year in the pilot study (n=85) was -5.2 (6.3) kg (mean \[SD\]) in the intervention group vs. -0.1 (6.5) kg in the control group (P \< 0.05), using intent to treat analysis with baseline values carried forward for dropouts. Specific aims: (1) To test whether the intervention promotes weight loss and maintenance of that loss over an 18-month time period in a larger group; (2) To describe the effect of the intervention on hormonal factors (insulin, leptin, IGF-I, IGFBP-1, IGFBP-3, sex-hormone binding globulin, and serum estrogens); and (3) To describe the relationships between body weight and weight reduction and measures of psychosocial factors (health-related quality of life, fatigue, depression, eating attitudes, and weight and shape concerns). Study design: The study targets 253 overweight or obese women previously treated for early stage breast cancer and utilizes a randomized study design with subjects assigned to the group-based healthy weight management program (with individualized telephone counseling support) or a wait-list control group. Data collection includes anthropometric and psychosocial measures, body composition (dual-energy x-ray absorptiometry), cardiopulmonary fitness testing, and hormonal measures at baseline and six and 18 months.