BRCA1 and breast carcinoma: The BRCA BCY Collaboration (ClinicalTrials.gov identifier: NCT03673306) is the largest global cohort of BRCA carriers with diagnosis of breast cancer at young age.11 Hence, this study represents a unique real-world cohort to explore the clinical behavior of breast cancer in young BRCA1 and BRCA2 carriers separately and the association of the timing of genetic testing with prognosis.