目标治疗（TT）与内分泌治疗（ET）的结合已经改善了HR阳性、HER2阴性转移性乳腺癌（mBC）患者的预后。然而，目前尚不清楚有侵袭性小叶癌（ILC）或混合侵袭性导管和小叶癌（混合型）组织学的患者是否与侵袭性导管癌（IDC）患者同样从这种治疗中受益。我们的目标是确定患有IDC、ILC和混合型HR+/HER2- mBC的患者是否从在ET中加入细胞周期蛋白依赖性激酶4和6抑制剂（CDK4/6i）、哺乳动物雷帕霉素靶点抑制剂（mTORi）和磷酸肌醇3-激酶抑制剂（PI3Ki）治疗中获得相似的益处。我们使用MD Anderson前瞻性收集数据库的数据进行了基于人群的观察性研究。我们对3784位接受TT加ET治疗的HR+/HER2- mBC患者进行了组织学分析，研究疾病进展生存期（PFS）和总生存期（OS）的持续时间。在3784名患者中，最终纳入了2975位患者。其中，CDK4/6is治疗的2249例患者中，81％为IDC、15％为ILC、4％为混合型；1027例患者接受了everolimus治疗（82％为IDC、14％为ILC、4％为混合型），49例患者接受了alpelisib（81％为IDC和19％为ILC）。在IDC、ILC和混合型HR+/HER2- mBC患者中，TT加ET治疗并未导致PFS或OS持续时间上的显着差异。我们结论是对于HR+/HER2- mBC患者，无论其组织学类型如何，将TT加入ET治疗中具有相似的益处。©2022年作者(s)。

The addition of targeted therapies (TT) to endocrine therapy (ET) has improved the outcomes of patients with HR-positive, HER2-negative metastatic breast cancer (mBC). However, it is unknown whether patients with invasive lobular carcinoma (ILC) or mixed invasive ductal and lobular carcinoma (mixed) histologies experience the same magnitude of benefit from this therapy as those with invasive ductal carcinoma (IDC). We aim to determine whether patients with IDC, ILC, and mixed HR+/HER2- mBC derive similar benefit from the addition of cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6is), mammalian target of rapamycin inhibitor (mTORi), and phosphoinositide 3-kinase inhibitor (PI3Ki) to ET in HR+/HER2- mBC. We conducted an observational, population-based investigation using data from the MD Anderson prospectively collected database. We conducted a histology-based analysis of progression-free survival (PFS) and overall survival (OS) durations in 3784 patients with HR+/HER2- mBC who were treated with TT plus ET between January 1, 2010, and December 31, 2021. Out of the 3784 patients, 2975 were included in the final analysis. Of these, 2249 received CDK4/6is (81% IDC, 15% ILC, and 4% mixed), 1027 received everolimus (82% IDC, 14% ILC, and 4% mixed) and 49 received alpelisib (81% IDC and 19% ILC). The addition of targeted therapy to ET did not result in statistically significant differences in PFS or OS duration among patients with IDC, ILC, and mixed HR+/HER2- mBC. We concluded that for patients with HR+/HER2- mBC, the addition of TT to ET leads to a similar magnitude of benefit, irrespective of histology.© 2022. The Author(s).