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

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.