Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Breast Oncology, Peking University Cancer Hospital and Institute, Beijing, China.
Cancer. 2024 Apr 15;130(S8):1476-1487. doi: 10.1002/cncr.35174. Epub 2024 Jan 10.
Cyclin-dependent kinase 4/6 inhibitors combined with endocrine therapy (ET) comprise the standard treatment for patients with hormone receptor-positive and human epidermal growth factor 2 (HER2)-negative metastatic breast cancer. The optimal systematic treatment after progression on palbociclib and the role of HER2 expression among these patients remain unclear.
The authors retrospectively identified 361 patients who received palbociclib combined with ET. Progression-free survival (PFS) and overall survival (OS) were analyzed based on subsequent treatments and HER2 status (PFS and OS, respectively). PFS1 and OS1 were calculated from palbociclib administration to disease progression/death and death from any cause, respectively. PFS and OS were calculated from subsequent treatment initiation.
The median PFS1 and OS1 were 10.2 and 39.9 months, respectively. The median PFS and OS of 111 patients (54.7%) who received chemotherapy were 4.9 months and 20.0 months, respectively, whereas those of 89 patients (43.8%) who received endocrine backbone therapy were 5.9 months and 29.3 months, respectively. Among them, 31 patients (15.3%) who received abemaciclib combined with new ET showed better PFS and OS (12.2 months and not reached, respectively). The median PFS1 was significantly shorter in the HER2-low subgroup than in the HER2-zero subgroup among patients who received second-line or later palbociclib (6.1 vs. 7.8 months; p = .040) but did not differ among patients who received first-line palbociclib.
Various regimens after palbociclib use were received. An improvement was noted in PFS among patients who received endocrine backbone therapy relative to chemotherapy, which may have been secondary to the receipt of chemotherapy by patients with more aggressive disease. HER2 status was not related to the effect of first-line palbociclib, but it may play a role in later lines.
细胞周期蛋白依赖性激酶 4/6 抑制剂联合内分泌治疗（ET）构成了激素受体阳性和人表皮生长因子 2（HER2）阴性转移性乳腺癌患者的标准治疗方法。在帕博西尼治疗进展后，最佳的系统治疗方案以及这些患者中 HER2 表达的作用尚不清楚。
作者回顾性地确定了 361 名接受帕博西尼联合 ET 治疗的患者。根据后续治疗和 HER2 状态（分别为无进展生存期 [PFS] 和总生存期 [OS]）分析无进展生存期（PFS）和总生存期（OS）。从帕博西尼给药到疾病进展/死亡和任何原因导致的死亡分别计算 PFS1 和 OS1。从后续治疗开始计算 PFS 和 OS。
中位 PFS1 和 OS1 分别为 10.2 和 39.9 个月。接受化疗的 111 名患者（54.7%）的中位 PFS 和 OS 分别为 4.9 个月和 20.0 个月，而接受内分泌骨干治疗的 89 名患者（43.8%）的中位 PFS 和 OS 分别为 5.9 个月和 29.3 个月。其中，31 名（15.3%）接受阿贝西利联合新 ET 治疗的患者表现出更好的 PFS 和 OS（12.2 个月和未达到，分别）。在接受二线或二线以上帕博西尼治疗的患者中，HER2 低亚组的中位 PFS1 明显短于 HER2 零亚组（6.1 与 7.8 个月；p = 0.040），但在接受一线帕博西尼治疗的患者中，两组之间无差异。
接受了各种方案的帕博西尼治疗后。与化疗相比，接受内分泌骨干治疗的患者的 PFS 有所改善，这可能是由于病情较重的患者接受了化疗。HER2 状态与一线帕博西尼的疗效无关，但可能在后续治疗中起作用。
