Endocrine Therapy With Abemaciclib or Chemotherapy as Initial Metastatic Treatment in ER+/HER2- Breast Cancer

Paclitaxel is administrated at the dose of 80 mg/m² as a 1-hour intravenous infusion every week (i.e., D1, D8 and D15) of a 3-week cycle

Capecitabine is given orally at a dose of 2000 to 2500 mg/m² daily for 14 days followed by a 7-day rest period every 3 weeks

Letrozole is administered orally at 2.5 mg/day continuous for patients nonsteroidal aromatase inhibitor naïve or relapsing \>1 year after the end of adjuvant endocrine therapy.

Anastrozole is administered orally at 1 mg/day continous for patients nonsteroidal aromatase inhibitor (NSAI) naïve or relapsing \>1 year after the end of adjuvant endocrine therapy.

Fulvestrant is administered at the dose of 500 mg intramuscular on D1-D15-D29 (as a loading dose), and then 500 mg every 28 days (as a maintenance dose) for patients relapsing on adjuvant or less than one year after completion of adjuvant NSAI.

Oral 150 mg BID continuous