Radiotherapy With Extreme Hypofractionation in Patients With Breast Cancer in Brazil: a Retrospective Cohort Study

All patients diagnosed with breast cancer who meet the eligibility criteria at participating centers will be included. Data will be collected from medical records at selected centers. Data collection will start from the location activation date. Data from up to 500 patients are expected to be collected at centers across Brazil. Patients recruited for this study will be identified at participating centers. Data on clinical, demographic and socioeconomic variables will be collected, as well as data on treatments performed and outcomes. The patient data sources will be the patients' medical records. Patients will continue to receive treatment and clinical evaluations for their illness as determined by their medical team, in accordance with the standards of care and usual clinical practice at each center. No intervention is proposed in this study.