[Palbociclib combinations as new therapeutic strategies in the treatment of HR+/HER2- advanced breast cancer].

Until recently, the only endocrine agents used to treat HR+/HER2- advanced breast cancers were tamoxifen, aromatase inhibitors and fulvestrant, although a substantial proportion of patients relapse on these standard therapies. Intensive research has been conducted to develop new strategies to overcome endocrine resistance and to enhance the efficacy of endocrine treatments by combining hormone therapy with other targeted treatment approaches. The development of selective CDK4/6 inhibitors and the introduction of palbociclib, the first molecule in this class in clinical practice, represent an important step in the treatment of HR+ advanced breast cancer. High level evidence supports the use of palbociclib plus letrozole in the treatment of endocrine sensitive breast cancers, or palbociclib plus fulvestrant in tumors that develop acquired resistance to endocrine therapy. These combinations are effective and well tolerated therapeutic modalities. The new combination regimens with palbociclib represent an important addition to the therapeutic armamentarium in locally advanced and metastatic ER+/HER2- breast cancer. The article reviews the current role of palbociclib in combination with endocrine therapy in the therapy of HR+/HER2- advanced breast cancer.