University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA.
Department of Biostatistics & Epidemiology, Hudson College of Public Health, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma, USA.
Oncology. 2022;100(6):337-343. doi: 10.1159/000524340. Epub 2022 Mar 28.
In patients with hormone receptor-positive metastatic breast cancer, palbociclib has been shown to improve overall survival and progression-free survival (PFS) when combined with endocrine therapy. Dose modification of palbociclib is effective in the management of adverse events. Despite variable clinical response, no predictive biomarkers of efficacy to palbociclib have been identified in metastatic breast cancer. In our study, we aimed to assess the PFS of metastatic breast cancer patients who received dose-reduced palbociclib and compare the results in the non-dose-reduced group. We also evaluated the clinical significance of progesterone receptor (PR) and Ki67 as predictive biomarkers of palbociclib.
Seventy-six palbociclib-treated metastatic breast cancer patients were included in our study. PFS was compared between dose-reduced and non-dose-reduced groups. PR expression and Ki67 status were assessed by immunohistochemistry. Kaplan-Meier method and log-rank test were used to analyze PFS.
Of the 76 patients, 40 (52.6%) experienced dose reduction (DR). Statistical analysis of the results revealed that there were no statistically significant differences observed between dose-reduced (16.5 months) versus non-dose-reduced (17.7 months) patients in PFS (p = 0.5493). For patients with Ki67 ≥14%, PFS was 15.2 months (95% CI: 10.2-22.2 months; p = 0.3024). In patients with PR ≥20%, median PFS was 25.0 months (lower 95% CI: 16.8 months; p = 0.0069).
Our study indicated that DR of palbociclib is frequently required but does not appear to affect PFS. PR expression was suggested to be a significant predictive factor for palbociclib responsiveness.
在激素受体阳性转移性乳腺癌患者中，与内分泌治疗联合应用帕博西利可改善总生存期和无进展生存期（PFS）。帕博西利剂量调整可有效管理不良反应。尽管临床反应存在差异，但在转移性乳腺癌中尚未确定帕博西利疗效的预测性生物标志物。在我们的研究中，我们旨在评估接受剂量减少的帕博西利治疗的转移性乳腺癌患者的 PFS，并比较非剂量减少组的结果。我们还评估了孕激素受体（PR）和 Ki67 作为帕博西利预测性生物标志物的临床意义。
我们的研究纳入了 76 名接受帕博西利治疗的转移性乳腺癌患者。比较了剂量减少组和非剂量减少组之间的 PFS。通过免疫组织化学评估 PR 表达和 Ki67 状态。采用 Kaplan-Meier 法和对数秩检验分析 PFS。
在 76 名患者中，40 名（52.6%）经历了剂量减少（DR）。结果的统计学分析显示，剂量减少组（16.5 个月）与非剂量减少组（17.7 个月）的 PFS 之间无统计学显著差异（p=0.5493）。对于 Ki67≥14%的患者，PFS 为 15.2 个月（95%CI：10.2-22.2 个月；p=0.3024）。在 PR≥20%的患者中，中位 PFS 为 25.0 个月（下 95%CI：16.8 个月；p=0.0069）。
我们的研究表明，帕博西利的 DR 经常需要，但似乎不会影响 PFS。PR 表达被认为是帕博西利反应的一个重要预测因素。
