Real-World Outcomes of Patients With Metastatic Breast Cancer After Treatment With First-Line ET+CDK4/6i

Inclusion Criteria

• •Patients with evidence of Stage IV or recurrent mBC with a metastatic diagnosis date on or after January 1, 2017
• •Aged ≥18 years at mBC diagnosis date
• •Received 1L ET + CDK 4/6i, with no other systemic agents, in the metastatic setting
• •Had evidence of a rwP event during 1L ET + CDK 4/6i
• •Evidence of a subsequent LOT following 1L ET + CDK 4/6i (start date of subsequent LOT = index treatment date)
• •A record of HR+ status in the closest estrogen receptor (ER) or progesterone receptor (PR) test result occurring prior to or within 30 days after the index treatment date
• •A record of HER2- status in the closest HER2 test result recorded prior to or on the index treatment date
• •Index treatment date occurring at least 90 days prior to end of study period (30Sep2024)