Inclusion Criteria:  Diagnosed with HER2-negative ABC gBRCA1/2 mutation(s)  Treatment with talazoparib monotherapy initiated on or after October 16, 2018  -≥18 years of age at initiation of talazoparib  A minimum of 6 months follow-up time after initiation of talazoparib unless the patient died within this follow-up period  Exclusion Criteria:  Participation in any BC clinical trial after initiation of talazoparib Treatment with a PARP inhibitor as neoadjuvant/adjuvant therapy gBRCA1/2 or HER2 status unknown Diagnosis of any other malignancy, except carcinoma in situ or nonmelanoma skin cancer, within the 5 years prior to data collection