Lactate Dehydrogenase As A Prognostic Biomarker In Patients With Hormone Receptor-Positive Metastatic Breast Cancer Treated With Palbociclib: An Exploratory Cohort Study

Background: Cyclin-dependent kinases (CDK) 4/6 inhibitors have recently reshaped the therapeutic scenario for hormone receptor (HR)-positive/HER2-negative metastatic breast cancer (MBC). Elevated serum lactate dehydrogenase (LDH) levels correlate with poor prognosis in various malignancies, including MBC. However, no data are available on LDH prognostic value in patients treated with CDK4/6 inhibitors. Henceforth, we explored whether plasmatic LDH could represent a prognostic biomarker in patients treated with endocrine therapy (ET) and the CDK4/6 inhibitor palbociclib.