Indian J Cancer. 2025 Oct 1;62(4):541-547. doi: 10.4103/ijc.ijc_643_23. Epub 2026 Mar 7.
ABSTRACT
BACKGROUND: CDK4/6 inhibitors have become the standard of care for the treatment of HR+ metastatic breast cancer (MBC) based on clinical trials. However, real-world experience and efficacy in various subgroups are still lacking. Therefore, we conducted a study to analyze the use of CDK4/6 inhibitors in the treatment of HR-positive MBC and assess the related outcomes.
METHODS: A total of 120 patients who received CDK4/6 inhibitors from 2015 to 2021 were analyzed. Detailed clinical, demographic information and tumor-related factors were obtained for each patient. Progression-free survival (PFS), toxicity profile, and tolerance to CDK4/6i were analyzed and correlated.
RESULTS: Among the 120 patients analyzed, 100 received palbociclib, while ribociclib, and abemaciclib were given to ten patients each. The median age of the population was 57 years. With a median follow-up of 28 months, the median PFS and overall survival (OS) were 25 and 54 months, respectively. The PFS did not significantly differ among different anti-hormonal agents used in combination with CDK4/6 inhibitors. Patients who were resistant to endocrine therapy had a shorter PFS compared to treatment-naive MBC patients (22 versus 40 months). Patients with strong hormonal receptor expression had a significantly better PFS compared to those with weak expression (25 versus 14 months). Her2Neu-negative patients responded better than those with low positive expression (P = 0.039). Visceral metastatic disease was associated with a significantly shorter PFS (17 months) compared to skeletal metastasis (32 months). There was no statistical significance when CDK4/6 inhibitors were used in different lines of treatment or with dose reduction.
CONCLUSION: CDK4/6 inhibitors demonstrate similar responses and better tolerance in real-world evidence. Further studies are necessary to identify other predictive and resistance factors for the use of CDK4/6 inhibitors.
PMID:41797591 | DOI:10.4103/ijc.ijc_643_23
