Circulating Tumor DNA (ctDNA)-Guided Late-Line Treatment in Patients With Late-Stage Breast Cancer

Clinical Application of Circulating Tumor DNA (ctDNA) to Guided the Late-Line Treatment for Patients With Late-Stage Breast Cancer

This is a retrospective, observational, multi-center clinical study of circulating tumor DNA (ctDNA) to guide late-line therapy in late-stage metastatic breast cancer patients.

This study aims to evaluate the feasibility of plasma ctDNA mutation in guiding late-line treatment for late-stage metastatic breast cancer patients. Meanwhile, this study tries to evaluate the curative effect of ctDNA subtype-guided late-line therapy.

Inclusion Criteria:

• Recent progression of TNBC after multiple lines of chemotherapy or of HR+ or HER2+ MBC after multiple lines of endocrine or targeted therapy;
• No available recommendation for the next treatment regimen;
• An Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2;
• An updated, available pathological HR/HER2 status for metastasis;
• According to RECIST 1.1 standard, there should be at least one measurable target lesion;
• The expected survival time is > 3 months;
• Those aged 18-70 years old;
• Liver and kidney function and blood routine test meet the following conditions: Neutrophil > 2.0g/l, Hb > 9g / L, PLT > 100g / L; ALT and AST < 2.5ULN; TBIL < 1.5ULN; Cr < 1.0ULN
• Signing informed consent;
• Those willing to accept polygenic testing.

Exclusion Criteria:

• Patients with multiple primary tumors;
• Those who are unable to obtain blood samples;
• Those with a history of immunodeficiency or organ transplantation;
• Those with abnormal cardiac function or previous history of myocardial infarction or serious arrhythmia;
• The researchers think it is not suitable to participate in this experiment.