Absolute lymphocyte count and neutrophil-to-lymphocyte ratio as predictors of CDK 4/6 inhibitor efficacy in advanced breast cancer

• Published in: Scientific reports Vol. 14; no. 1; p. 9869
• Main Authors: Nakamoto, Shogo, Shien, Tadahiko, Iwamoto, Takayuki, Kubo, Shinichiro, Yamamoto, Mari, Yamashita, Tetsumasa, Kuwahara, Chihiro, Ikeda, Masahiko
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 30.04.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 692/308; 692/4028; Adult; Aged; Aged, 80 and over; Aminopyridines - therapeutic use; Benzimidazoles - therapeutic use; Breast cancer; Breast Neoplasms - blood; Breast Neoplasms - drug therapy; Breast Neoplasms - mortality; Breast Neoplasms - pathology; Cell number; Cyclin-dependent kinase 4; Cyclin-Dependent Kinase 4 - antagonists & inhibitors; Cyclin-Dependent Kinase 6 - antagonists & inhibitors; Cyclin-dependent kinases; Endocrine therapy; ErbB-2 protein; Estrogen receptors; Estrogens; Female; Humanities and Social Sciences; Humans; Kinases; Leukocytes (neutrophilic); Lymphocyte Count; Lymphocytes; Lymphocytes - metabolism; Middle Aged; multidisciplinary; Neutrophils; Patients; Piperazines - therapeutic use; Protein Kinase Inhibitors - therapeutic use; Pyridines - therapeutic use; Receptor, ErbB-2 - antagonists & inhibitors; Receptor, ErbB-2 - metabolism; Retrospective Studies; Science; Science (multidisciplinary); Treatment Outcome
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-024-60101-x

Cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i) are the standard agents for treating patients with estrogen receptor-positive and human epidermal growth factor receptor 2-negative advanced breast cancer (ER + HER2 − ABC). However, markers predicting the outcomes of CDK4/6i treatment have yet to be identified. This study was a single-center retrospective cohort study. We retrospectively evaluated 101 patients with ER + HER2 − ABC receiving CDK4/6i in combination with endocrine therapy at Fukuyama City Hospital between November 2017 and July 2021. We investigated the clinical outcomes and the safety of CDK4/6i treatment, and the absolute lymphocyte count (ALC) and neutrophil-to-lymphocyte ratio (NLR) as predictive markers for CDK4/6i. We defined the cut-off values as 1000/μL for ALC and 3 for NLR, and divided into “low” and “high” groups, respectively. We evaluated 43 and 58 patients who received abemaciclib and palbociclib, respectively. Patients with high ALC and low NLR had significantly longer overall survival than those with low ALC and high NLR (high vs. low; ALC: HR 0.29; 95% CI 0.12–0.70; NLR: HR 2.94; 95% CI 1.21–7.13). There was no significant difference in efficacy between abemaciclib and palbociclib and both had good safety profiles. We demonstrated that ALC and NLR might predict the outcomes of CDK4/6i treatment in patients with ER + HER2 − ABC.