This prospective multicenter observational study (NEOBRE-STEP) investigates the impact of daily step counts, measured by Huawei Fit 2 smartwatches, on treatment response in patients with non-metastatic Human Epidermal Growth Factor Receptor 2 (HER2)-negative breast cancer undergoing neoadjuvant systemic therapy. Patients will wear smartwatches to continuously record step counts, activity intensity, sleep, and heart rate. Patient-reported outcomes, including sleep quality (Pittsburgh Sleep Quality Index, PSQI) and quality of life (European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire - Core 30, EORTC QLQ-C30), will be assessed at baseline and after treatment. The primary outcomes are pathological complete response (pCR) and Miller-Payne score. Secondary outcomes include sleep quality, quality of life, perioperative outcomes, and feasibility of smartwatch monitoring.
Female patients aged ≥18 years.
Pathologically confirmed non-metastatic HER2-negative breast cancer.
Candidates scheduled to receive neoadjuvant systemic therapy followed by surgery.
ECOG performance status 0-2.
Metastatic breast cancer at diagnosis.
HER2-positive breast cancer.
Previous systemic therapy for current breast cancer.
Severe comorbidities limiting mobility or physical activity (e.g., advanced neurologic or musculoskeletal disorders).