JPM, Vol. 14, Pages 464: Cyclin-Dependent Kinase 4/6 Inhibitors Plus Endocrine Therapy versus Endocrine Therapy Alone for HR-Positive, HER-2-Negative Early Breast Cancer: Meta-Analysis of Phase III Randomized Clinical Trials

JPM, Vol. 14, Pages 464: Cyclin-Dependent Kinase 4/6 Inhibitors Plus Endocrine Therapy versus Endocrine Therapy Alone for HR-Positive, HER-2-Negative Early Breast Cancer: Meta-Analysis of Phase III Randomized Clinical Trials

Journal of Personalized Medicine doi: 10.3390/jpm14050464

Authors: Francisco Cezar Aquino de Moraes Gustavo de Oliveira Almeida Vinícius Freire Costa Alves Jonathan N. Priantti Giovanna da Conceição Gomes Sarah Vitória Bristot Carnevalli Thiago Madeira Maysa Vilbert Carlos Stecca Maria Cristina Figueroa Magalhães Marianne Rodrigues Fernandes Ney Pereira Carneiro dos Santos

Background: Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors are approved for advanced breast cancer combined with endocrine therapy (ET). The efficacy of CDK4/6 inhibitors plus ET in hormone estrogen-positive, human epidermal growth factor 2-negative (HR+/HER2−) early-stage breast cancer (esBC) is still to be confirmed. Methods: We performed a systematic review and a meta-analysis to investigate the efficacy of CDK4/6i plus ET in esBC. Main outcomes included invasive disease-free survival (iDFS), distant relapse-free survival (DRFS), and overall survival (OS). We included only phase III randomized controlled trials. We used RStudio version 4.2.3, and we considered p < 0.05 to be statistically significant. Results: Four studies were selected, including 14,168 patients, of which 7089 were treated with CDK4/6i plus ET and 7079 received ET monotherapy. Regarding patient characteristics, 6828 (48.2%) were premenopausal. Compared with ET alone, iDFS rates (HR 0.81; 95% CI: 0.67, 0.98; p = 0.034) were significantly in favor of CDK4/6 inhibitors plus ET. However, there were no significant differences in DRFS (HR 0.79; 95% CI: 0.58, 1.07; p = 0.132) nor OS (HR 0.96; 95% CI: 0.69, 1.35; p = 0.829). Conclusions: Our results show that the addition of CDK4/6 inhibitors is associated with a significant benefit for HR+/HER2− esBC patients in iDFS. More studies and longer follow-up are needed to assess overall survival benefits.