Cyclin D1 amplification and loss of p16 (CDKN2A) are found in a hormone receptor-positive breast cancer biopsy. Which CDK4/6 inhibitor combination is standard first-line therapy in metastatic HR+/HER2- disease based on MONARCH 3 or PALOMA-3 trial data?
- A Palbociclib + letrozole ✓
- B Abemaciclib + fulvestrant
- C Ribociclib + tamoxifen
- D Everolimus + exemestane
Correct answer: A. Palbociclib + letrozole
Explanation
PALOMA-2 and PALOMA-3 established palbociclib (CDK4/6 inhibitor) in combination with letrozole (aromatase inhibitor) as first-line therapy for postmenopausal women with HR+/HER2- metastatic breast cancer, significantly improving progression-free survival. MONARCH 3 supports abemaciclib + non-steroidal AI as first-line. However, palbociclib + letrozole remains the most widely cited and tested first-line combination from landmark trials. Everolimus + exemestane (BOLERO-2) is used after AI failure. Fulvestrant combinations are often used in second-line settings.
Reference: Bailey & Love's Short Practice of Surgery, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.