The largest portion of breast cancer patients diagnosed after 70 years of age present with hormone receptor-positive (HR+) breast cancer subtypes. Cyclin-dependent kinase (CDK) 4/6 inhibitor treatment, in conjunction with endocrine therapy, has become standard-of-care for metastatic HR+ breast cancer. In total, 320 patients with metastatic breast cancer receiving CDK4/6 inhibitor combined with fulvestrant or an aromatase inhibitor were enrolled in an ongoing observational study or were included in an IRB-approved retrospective study. All patients receiving CDK4/6 inhibitor-based therapy that were ≥70 years of age (n = 111) displayed prolonged progression-free survival (27.6 months) as compared to patients <70 years of age (n = 209, 21.1 months, HR = 1.38,p< 0.05). Specifically, patients receiving a CDK4/6 inhibitor with an aromatase inhibitor who were ≥70 years of age (n = 79) displayed exceptionally prolonged progression-free survival (46.0 months) as compared to patients receiving the same treatment who were <70 years of age (n = 161, 21.8 months, HR = 1.71,p< 0.01). However, patients ≥70 years of age also experienced more frequent adverse responses to CDK4/6 inhibitor-based treatment leading to dose reduction, hold, or discontinuation than the younger cohort (69% and 53%, respectively). Treatment strategies that may decrease toxicity without affecting efficacy (such as dose titration) are worth further exploration.
70岁以上确诊的乳腺癌患者中，激素受体阳性（HR+）亚型占比最高。细胞周期蛋白依赖性激酶（CDK）4/6抑制剂联合内分泌治疗已成为转移性HR+乳腺癌的标准治疗方案。一项正在进行的观察性研究或经机构审查委员会批准的回顾性研究共纳入320例接受CDK4/6抑制剂联合氟维司群或芳香化酶抑制剂治疗的转移性乳腺癌患者。所有接受CDK4/6抑制剂为基础治疗的≥70岁患者（n=111）与<70岁患者（n=209）相比，显示出更长的无进展生存期（27.6个月 vs 21.1个月，HR=1.38，p<0.05）。具体而言，接受CDK4/6抑制剂联合芳香化酶抑制剂治疗的≥70岁患者（n=79）与接受相同治疗的<70岁患者（n=161）相比，无进展生存期显著延长（46.0个月 vs 21.8个月，HR=1.71，p<0.01）。然而，≥70岁患者在接受CDK4/6抑制剂为基础治疗时，因不良反应导致剂量减少、暂停或终止治疗的发生率也高于年轻组（分别为69%和53%）。值得进一步探索在不影响疗效的前提下降低毒性的治疗策略（如剂量滴定）。
肿瘤(癌症)患者之家