Observational Analysis of Palbociclib Treatment in Patients With First Line Therapy for Locally Advanced and/or Metastatic Breast Cancer

Inclusion Criteria

• •1\. Documented histologically confirmed breast cancer with ER and/or PgR positive and HER2 negative status.
• •2\. Locally advanced or metastatic breast cancer not deemed amenable to curative surgery or curative radiation therapy
• •3\. HR+/HER2-
• •1. HR+: ER+ or PR+ test before or up to 60 days after MBC diagnosis
• •2. HER2-: any HER2 negative test and the absence of a positive test (IHC positive 3+, FISH positive/amplified, Positive NOS) before or up to 60 days after MBC diagnosis
• •4\. Female or male patients \> 18 years
• •5\. Have received at least one dose of palbociclib
• •6\. At least 2 document clinical visits
• •7\. Treatment with palbociclib should have started from November 2017 to November 2019
• •8\. Data from the clinical records should be available.
• •9\. Patients must be able to understand and sign informed consent if alive.