The Impact of Obesity on Treatment Outcomes in Patients with Hormone Receptor–Positive HER2-Negative Metastatic Breast Cancer Receiving CDK 4/6 Inhibitors
- Author:
Yoo Bin JUNG
1
;
Hee Kyung AHN
;
Hyun-Young SHIN
;
Ji Hyung HONG
;
Chai Hong RIM
Author Information
- Publication Type:Original Article
- From:Cancer Research and Treatment 2026;58(1):198-207
- CountryRepublic of Korea
- Language:English
-
Abstract:
Purpose:Guidelines from the aromatase inhibitor era for early breast cancer (EBC) treatment recommend maintaining a body mass index (BMI) below 25. In the current era of cyclin-dependent kinase (CDK) 4/6 inhibitors, now standard in metastatic breast cancer (MBC), limited data exist on treatment outcomes in obese patients. This study investigates how adiposity affects the treatment outcome of CDK 4/6 inhibitors in patients with hormone receptor–positive, human epidermal growth factor receptor 2–negative MBC.
Materials and Methods:We searched PubMed, MEDLINE, and Embase databases, assessing efficacy outcomes such as progression-free survival (PFS) based on obesity markers, including BMI and visceral adipose tissue (VAT) index.
Results:Twelve studies were reviewed, with seven studies and 1,812 patients included in a pooled meta-analysis. Among patients with BMI ≥ 25, modest improvement in PFS was observed, with a pooled hazard ratio (HR) of 0.944 (95% confidence interval [CI], 0.909 to 0.980; p=0.003). Besides, add-on analysis using VAT to define obesity revealed a notable PFS improvement, with a pooled HR of 0.452 (95% CI, 0.256 to 0.798; p=0.006).
Conclusion:While BMI-defined obesity showed slight PFS improvement with CDK 4/6 inhibitors and endocrine therapy, using VAT to define obesity revealed significant PFS gains. This highlights the need for further research on biomarker to clarify the role of adiposity in MBC, which may differ from its impact in EBC.
