In systemic breast cancer treatments, most serious toxicities emerge at the patient’s home, between chemotherapy or immunotherapy cycles, when intensive hospital monitoring is no longer in place. This care gap translates into unplanned emergency visits, avoidable readmissions, and a significant clinical, economic, and emotional burden for patients, families, and health systems. Conventional early warning scores were designed for inpatient settings with intermittent measurements. They are not optimized to interpret continuous biosensor signals in real‑life conditions, nor to distinguish normal physiological variability and sensor artifacts from true clinical deterioration in vulnerable oncology patients.