在人类表皮生长因子受体 2 (HER2) 阳性乳腺癌 (BC) 治疗不断发展的格局中，液体活检为指导临床决策提供了前所未有的机会。在这里，我们回顾了液体活检在 HER2 阳性 BC 中应用的最新发现，及其在解决该 BC 亚型特有挑战方面的潜在作用。最近的研究强调了液体活检分析物的重要性，主要是循环肿瘤 DNA (ctDNA) 和循环肿瘤 DNA肿瘤细胞 (CTC)，用于对患者预后进行分层、预测治疗反应以及监测 BC 早期和晚期的肿瘤演变。液体活检有望研究微小残留病，以便在疾病出现临床表现之前检测并可能治疗疾病复发。此外，液体活检可能对脑转移的治疗具有重要意义，脑转移是 HER2 阳性 BC 的主要挑战，并且可以重新定义确定 HER2 阳性的参数。结合 ctDNA 和 CTC 对于全面了解 HER2 阳性肿瘤至关重要，因为它们提供了互补的见解。需要开展研究工作来解决分析挑战、验证和扩大液体活检在 HER2 阳性 BC 中的应用。这项努力最终将促进其融入临床实践，优化 HER2 阳性肿瘤患者的护理。版权所有 © 2024 Wolters Kluwer Health, Inc. 保留所有权利。

In the evolving landscape of human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC) management, liquid biopsy offers unprecedented opportunities for guiding clinical decisions. Here, we review the most recent findings on liquid biopsy applications in HER2-positive BC and its potential role in addressing challenges specific to this BC subtype.Recent studies have highlighted the significance of liquid biopsy analytes, primarily circulating tumor DNA (ctDNA) and circulating tumor cells (CTCs), in stratifying patients' prognosis, predicting treatment response, and monitoring tumor evolution in both early and advanced stages of BC. Liquid biopsy holds promise in studying minimal residual disease to detect and potentially treat disease recurrence before it manifests clinically. Additionally, liquid biopsy may have significant implication in the management of brain metastasis, a major challenge in HER2-positive BC, and could redefine parameters for determining HER2 positivity. Combining ctDNA and CTCs is crucial for a comprehensive understanding of HER2-positive tumors, as they provide complementary insights.Research efforts are needed to address analytical challenges, validate, and broaden the application of liquid biopsy in HER2-positive BC. This effort will ultimately facilitate its integration into clinical practice, optimizing the care of patients with HER2-positive tumors.Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.