BACKGROUND: In young women, breast cancer (BC) has particular characteristics, such as a more advanced stage at diagnosis, aggressive tumor characteristics, and a poorer prognosis. NeoFit aims to use an activity tracker to identify and describe various digital profiles (physical activity, heart rate, sleep) in women under 70 years of age treated with neoadjuvant chemotherapy for BC.~METHODS: NeoFit is a prospective, national, multicenter, single-arm open-label study. It will include a total of 300 participants under the age of 70 years treated with neoadjuvant chemotherapy for BC. Participants will receive a Withing Steel HR activity tracker, which they will be asked to wear 24 h per day for 12 months. The principal assessments will be performed at baseline, at the end of neoadjuvant chemotherapy and at 12 months. The investigators will evaluate clinical (e.g. toxicity, efficacy of chemotherapy), lifestyle, quality of life, fatigue, and physical activity parameters. All questionnaires will be completed on a REDCap form, via a secure internet link.~DISCUSSION: NeoFit will make it possible, through the use of an activity tracker, to visualize changes, over a one-year period, in the lifestyle of young women treated for BC by neoadjuvant chemotherapy. This exploratory study will provide fundamental knowledge about the digital phenotypes of young BC patients treated with NAC and their relationships to chemotherapy toxicity and efficacy. This trial will pave the way for interventional studies on physical activity and sleep interventions.
NeoFit is a prospective, national, multicenter, single-arm open-label study. It will include a total of 300 participants under the age of 70 years treated with neoadjuvant chemotherapy for BC. Participants will receive a Withing Steel HR activity tracker, which they will be asked to wear 24 h per day for 12 months. The principal assessments will be performed at baseline, at the end of neoadjuvant chemotherapy and at 12 months. The investigators will evaluate clinical (e.g. toxicity, efficacy of chemotherapy), lifestyle, quality of life, fatigue, and physical activity parameters. All questionnaires will be completed on a REDCap form, via a secure internet link.