Ann Radiat Ther Oncol | Volume 1, Issue 2 | Research Article | Open Access
Ezzeldin M Ibrahim1*, Wesal M Eldahna1, Omalkhair A Abulkhair2, Mubarak M Al-Mansour3 and Meteb O Al-Foheidi3
1Department of Medicine & Oncology, International Medical Center, Kingdom of Saudi Arabia
2Department of Oncology, Specialized Medical Center, Kingdom of Saudi Arabia
3Department of Oncology, Princess Noorah Oncology Center, King Abdulaziz Medical City, Kingdom of Saudi Arabia
*Correspondance to: Ezzeldin M Ibrahim
Fulltext PDFAim: For decades, endocrine therapy (ET) has been the standard of care in the management of hormone-positive, HER2-negative advanced breast cancer. The addition of cyclin-dependent kinase 4/6 (CDK4/6) inhibitors to ET has significantly improved progression-free survival (PFS) for patients with that disease subtype. A meta-analysis to quantify the magnitude of benefit in all patients’ population and in relevant subgroups is warranted.
Methods: Comprehensive literature search identified 8 eligible randomized controlled trials (RCTs) comprising 4,580 patients and were included in the meta-analysis. Seven studies were placebo-controlled. All analyses were based on fixed-effects models.
Results: In five RCTs in the first-line setting, CDK4/6 inhibitors were associated with 44% improvement in PFS, (hazard ratio [HR]=0.56; 95% confidence interval [CI] 0.50-0.62; P<0.0001). Furthermore, in the second-line setting (3 RCTs), CDK4/6 inhibitors demonstrated a 47% improvement PFS (HR of 0.53; 95% CI 0.46-0.60; P<0.0001). Irrespective of patients’ subgroups, the benefit achieved with CDK4/6 inhibitors was consistent in either the first- or second-line setting. Compared with controls, CDK4/6 inhibitors achieved higher Objective Response Rate (ORR) and the pooled Odds Ratio (OR) was 1.97 (95% CI, 1.68-2.30; P <0.0001), with numerically higher OR in the second-line setting.
Conclusion: Combining CDK4/6 inhibitors with standard ET significantly improved PFS and ORR in hormone-positive, HER2-negative advanced breast cancer. The benefit was achieved in all patients’ subgroups.
Breast cancer; Advanced; CDK4/6 inhibitor
Ibrahim EM, Eldahna WM, Abulkhair OA, Al-Mansour MM, Al-Foheidi MO. CDK 4/6 Inhibitors in Hormone Receptor-Positive Advanced Breast Cancer: A Meta-Analysis. Ann Radiat Ther Oncol. 2018; 1(2): 1015.