Promoting weight loss through diet and exercise in overweight or obese breast cancer survivors (InForma): study protocol for a randomized controlled trial

摘要

Background Most women with breast cancer experience a progressive weight gain during and after treatment. Obesity is associated with an increased risk of recurrence, contralateral breast cancer, and death. Physical activity after cancer diagnosis has been reported to have positive effects on body composition and quality of life. We present the protocol of the InForma study, a trial testing the efficacy of an intervention on weight loss (≥5 % of the baseline body weight) in a group of overweight or obese breast cancer survivors. Methods/design This is a four-arm randomized controlled trial. Patients will receive a 6-month intervention and be followed for a further 18 months. Intervention is designed to improve adherence to a healthy diet and/or to increase physical activity, taking advantage of a wrist-based activity monitor. Participants will be recruited among overweight or obese breast cancer patients treated at the European Institute of Oncology, after completion of eventual adjuvant chemotherapy and/or radiotherapy. It is envisaged that 260 patients will be randomized into four arms: Dietary Intervention; Physical Activity Intervention; Physical Activity and Dietary Intervention; and Less Intensive Intervention. Women will be offered individualized counseling consisting of face-to face discussion and phone calls in addition to group meetings. A motivational interviewing approach will be used to encourage health behavior change. All participants will be given a pedometer device to monitor their physical activity. Participants’ dietary intake will be repeatedly assessed using a validated food frequency questionnaire. Participants’ quality of life and anxiety will be assessed with the Functional Assessment of Cancer Therapy-Breast and the State-Trait Anxiety Inventory questionnaires. Blood samples will be collected at baseline and follow-up visits to assess lipid and hormone profiles. Body composition will be repeatedly assessed using bioelectrical impedance vector analysis for identifying changes of fat and fat-free mass. Women allocated to the less intensive intervention arm will be considered as the control group. Discussion While there is a rising concern about the role of obesity in cancer recurrence and survival, this trial with its multi-arm design, motivational approach and use of a pedometer device will provide important insights regarding the most effective approach in promoting weight control in breast cancer survivors. Trial registration ISRCTN53325751 (registration date: 16 October 2015); ClinicalTrials.gov NCT02622711 (registration date: 2 December 2015).