Prognostic and Predictive Factors in Metastatic Breast Cancer Patients Treated with CDK4/6 Inhibitors

Creative Commons License

Demirel N., YILDIZ B., DEMİR M.

JCPSP-JOURNAL OF THE COLLEGE OF PHYSICIANS AND SURGEONS PAKISTAN, cilt.36, sa.5, ss.614-619, 2026 (SCI-Expanded, Scopus)

Özet

Objective: To evaluate the safety and efficacy of CDK4/6 inhibitors in combination with hormone therapy, and to investigate potential predictive markers of treatment in metastatic breast cancer (MBC). Study Design: An observational study. Place and Duration of the Study: Department of Medical Oncology, Faculty of Medicine, Eskisehir Osmangazi University, Eskisehir, Turkiye, from January 2019 to December 2023. Methodology: Eighty patients with HR+ HER2-MBC treated with CDK4/6 inhibitors were inducted. Mean overall survival (OS) and progression-free survival (PFS) were compared using t-tests or ANOVA, while Pearson's correlation was used to assess relationships between continuous variables and survival. Kaplan-Meier and Cox regression analyses were performed to analyse variables affecting PFS and OS and to determine treatment response to risk factors. Results: Ribociclib was used in 70 patients, and palbociclib in 10 patients. A significant difference in PFS was observed between the CDK4/6 inhibitor agents (p = 0.034), with a longer mean PFS in the palbociclib group. A weak negative correlation was found between NLR and PFS (r =-0.289, p = 0.010). The number of involved lymph nodes showed a weak positive correlation with OS (r = 0.327, p = 0.040). Time to metastasis and treatment duration contributed significantly to OS as an independent variable (p = 0.001 and p = 0.003), and the CDK4/6 agent contributed significantly to PFS as an independent variable (p = 0.008). There was no statistically significant change in OS with the preferred CDK4/6 agent. Conclusion: There is a significant difference in the use of CDK4/6, which may supplement standard hormone therapy in the treatment of HR+ HER2-MBC patients.