Absolute lymphocyte count predicts efficacy of palbociclib in patients with metastatic luminal breast cancer

作者：Takayuki Kobayashi, Meiko Nishimura, Mari Hosonaga, Rika Kizawa, Saori Kawai, Yosuke Aoyama, Yukinori Ozaki, Ippei Fukada, Fumikata Hara, Toshimi Takano, Takayuki Ueno · 发表于：BMC Cancer · 年份：2024 · DOI：10.1186/s12885-024-12941-z · 被引用次数：4 · 研究领域：Advanced Breast Cancer Therapies、Cancer Immunotherapy and Biomarkers、Cancer, Lipids, and Metabolism

BACKGROUND: Absolute lymphocyte count (ALC) is a predictive and prognostic factor for various tumor types, including breast cancer. Palbociclib is a CDK4/6 inhibitor widely used for the treatment of metastatic estrogen receptor (ER)-positive, HER2-negative breast cancer. However, predictive biomarkers of the efficacy of palbociclib remain unelucidated. We conducted a retrospective study to examine the predictive value of the baseline ALC in patients treated with palbociclib. METHODS: The medical records of patients with ER-positive, HER2-negative breast cancer treated with palbociclib plus hormonal therapy between December 2017 and December 2021 were analyzed retrospectively. The cutoff value of ALC was set at 1800 cells/μL at the initiation of palbociclib treatment. The clinical benefit rate (CBR) was defined as the rate of complete or partial response or stable disease for at least 6 months. Progression-free survival (PFS) rates were estimated using the Kaplan-Meier method and compared using the log-rank test. Univariate and multivariate analyses were performed using Cox proportional hazards regression. RESULTS: All of the 202 patients were women, with a median age of 59 years and a performance status (PS) of ≤ 2. The median numbers of lines of chemotherapy and endocrine therapy before palbociclib treatment were 0 (range, 0-9) and 1 (range, 0-7), respectively. Fifty-one patients had liver metastases. Forty-six patients tested negative for progesterone receptor (PgR) express...