摘要

<正>1文献来源Finn RS,Crown JP,Lang I,et al.The cyclindependent kinase 4/6 inhibitor Palbociclib in combination with Letrozole versus Letrozole alone asfirst-line treatment of oestrogen receptor-positive,HER2-negative,advanced breast cancer(PALOMA-1/TRIO-18):A randomised phase 2 study[J].Lancet Oncol,2015,16(1):25-35.2证据水平1b。3背景Palbociclib是一种口服细胞周期蛋白依赖性激酶(cyclin-dependent kinases,CDK)4/6小分子抑