Southeast Netherlands Advanced Metastatic Breast Cancer Registry

This SONABRE registry is an ongoing observational cohort study aiming at the inclusion of all patients aged ≥18 years and diagnosed with advanced breast cancer since 2007 in 11 hospitals in the Southeast of the Netherlands. Patients with de novo or recurrent advanced breast cancer were identified from the hospital-based management information systems. Specially trained registration clerks retrospectively collected data from the medical files of the patients based on extensive medical chart review. Information was collected about patient and tumour characteristics, type of treatment (surgery, radiotherapy and systemic treatment, both neo-adjuvant, adjuvant and palliative), palliative treatment changes due to adverse events, hospitalization, comorbidities and outcomes (progression and death). The SONABRE Registry has already been effectively used to perform real-life studies on the use, safety and (cost-)effectiveness of various systemic treatments used in patients diagnosed with advanced breast cancer.