A growing number of people with unilateral breast cancer have chosen to undergo contralateral prophylactic mastectomy in order to prevent the occurrence of second primary breast cancer and thus avoid associated treatment and death. Contralateral prophylactic mastectomy has been considered beneficial in high-risk populations, such as premenopausal BRCA1/2 mutation carriers. As a result, contralateral prophylactic mastectomy acceptance in patients with no such mutation is controversial. Contralateral prophylactic mastectomy can reduce the risk by up to 95%. Therefore, it is very important to evaluate the risk of contralateral breast cancer and to make appropriate surgical treatment. A review of risk factors for contralateral breast cancer and the benefits of contralateral prophylactic mastectomy in patients with unilateral breast cancer is presented.

Endocrine therapy is one of the standard treatment options for breast cancer which plays an important role in treating patients with estrogen receptor (ER) positive and human epidermal growth factor receptor 2 (HER2) negative breast cancer.However,some patients develop resistance during therapy due to factors such as tumor heterogeneity,which is particularly acute in the treatment of advanced breast cancer.Based on aiming at a rational and effective treatment,some clinical trials recently have demonstrated that compared to endocrine therapy alone,cyclin-dependent kinase 4/6 (CDK4/6) inhibitors combined with endocrine therapy can significantly improve the prognosis of ER-positive,HER2-negative advanced breast cancer.Its main products are Palbociclib,Ribociclib and Abemaciclib.This review mainly focuses on the mechanism and related clinical trials of CDK4/6 inhibitor inhibitors in ER-positive,HER2-negative advanced breast cancer.