Department of Obstetrics and Gynecology, University Hospital of Schleswig Holstein, Campus Lübeck, Lübeck, Germany,
Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany,
Oncol Res Treat. 2022;45(1-2):4-11. doi: 10.1159/000520561. Epub 2021 Oct 29.
In metastatic breast cancer (MBC), blood-based diagnostics have become a major focus of oncological research in the last 2 decades. Detection of circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA) has the potential to improve prognosis assessment and complement standard therapy monitoring tools.
To date, several large analyses have confirmed high CTC counts as an independent prognostic factor. Persistently high CTC numbers during systemic treatment are associated with early progression, but it remains to be clarified which therapeutic options should be offered to such patients since the SWOG 0500 trial failed to show benefit from early switch to another chemotherapy regimen in patients with CTC persistence. In comparison, evidence on the prognostic value of ctDNA is still limited. Most importantly, liquid biopsy-guided treatment interventions have been investigated in several trials. In patients with hormone receptor-positive and HER2-negative MBC, CTC-driven therapy choices resulted in similar PFS to physician's choice treatment. Recently, the DETECT III trial has shown that patients with HER2-negative MBC and HER2-positive CTCs may benefit from targeted anti-HER2 treatment with lapatinib. ctDNA-driven therapy selection has already been approved in clinical routine: alpelisib is the first targeted treatment indicated on the basis of a ctDNA test. Key Messages: CTCs and ctDNA predict clinical outcome and have a potential to improve therapy choices in MBC.
在转移性乳腺癌（MBC）中，血液诊断在过去 20 年中已成为肿瘤学研究的主要关注点。循环肿瘤细胞（CTC）和循环肿瘤 DNA（ctDNA）的检测有可能改善预后评估并补充标准治疗监测工具。
迄今为止，几项大型分析证实高 CTC 计数是独立的预后因素。系统治疗期间持续高 CTC 数量与早期进展相关，但仍不清楚应该向此类患者提供哪些治疗选择，因为 SWOG 0500 试验未能显示在 CTC 持续存在的患者中早期切换到另一种化疗方案的获益。相比之下，ctDNA 预后价值的证据仍然有限。最重要的是，液体活检指导的治疗干预已在多项试验中进行了研究。在激素受体阳性和 HER2 阴性 MBC 患者中，CTC 驱动的治疗选择与医生选择的治疗相比具有相似的无进展生存期。最近，DETECT III 试验表明，HER2 阴性 MBC 且 HER2 阳性 CTC 的患者可能受益于曲妥珠单抗联合 lapatinib 的靶向抗 HER2 治疗。ctDNA 驱动的治疗选择已在临床常规中获得批准：阿培利司是基于 ctDNA 测试的首个靶向治疗药物。
CTC 和 ctDNA 可预测临床结局，并有可能改善 MBC 的治疗选择。
