Aim: Endocrine therapy (ET) plus cyclin-dependent kinase (CDK) 4/6 inhibitors is a standard treatment for hormone receptor (HR) positive HER-2-negative metastatic breast cancer patients. In this study, we aimed to investigate the effect of body mass index (BMI) on progression-free survival (PFS) in patients receiving ET plus CDK 4/6 inhibitors.Materials & methods: Patients with metastatic HR-positive breast cancer receiving CDK 4/6 inhibitors were included in the study. A total of 116 patients were retrospectively evaluated. Patients were divided into three groups according to BMI level: normal weight (group 1) 18.5-24.9 kg/m2, overweight (group 2) 25-29.9 kg/m2 and obese (group 3): ≥30 kg/m2. Median follow-up was 10.83 months. Comparisons of PFS and BMI categories were performed by Kaplan-Meier curve and log-rank test.Results: PFS was 9.3 (5.3-13.4) months in normal weight patients and 11.1 (9.7-12.56) months in obese patients and was not reached in overweight patients. This difference was statistically significant (p = 0.02).Conclusion: Low BMI has been shown to have a negative prognostic effect on survival in patients with metastatic breast cancer and overweight patients had a longer PFS.
Keywords: CDK 4/6 inhibitors; body mass index; endocrine therapy; metastatic breast cancer; progression free survival.
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