Cdk4/6 inhibitor treatments in patients with hormone receptor positive, her2 negative advanced breast cancer: Potential molecular mechanisms, clinical implications and future perspectives
Hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer is the most common breast cancer subtype, and endocrine therapy (ET) remains its therapeutic backbone. Although anti-estrogen therapies are usually effective initially, approximately 50% of HR+ patients develop resistance to ET within their lifetime, ultimately leading to disease recurrence and limited clinical benefit.