Eribulin Mesylate-based Therapy in Patients With Advanced HER2-negative Breast Cancer Previously Treated With ADC

Inclusion criteria

• At least 18 years old;
• Inoperable locally advanced or metastatic breast cancer;
• Planning to use a single-agent or combination treatment regimen based on eribulin;
• HER2 negative (IHC 0,+, or ++ but ISH negative);
• Previously received ADC treatment at the local advanced or metastatic disease stage;
• Previously received chemotherapy (including ADC) for local advanced or metastatic disease no more than 2 lines, where one treatment line is defined as completing at least one cycle of chemotherapy;
• Eastern Cooperative Oncology Group (ECOG) performance status score (PS) 0-2;
• The investigators have evaluated that the patient's organ and bone marrow functions are suitable for medication use and there are no relevant contraindications;
• The subjects voluntarily join the study and sign the informed consent.

Exclusion criteria

• HER2-positive tumors
• The hormone receptor status is unknown;
• Patients who have received eribulin treatment before;
• Those who have had other malignant tumors within the past 5 years (excluding the following situations: cured skin basal cell carcinoma, cervical carcinoma in situ, papillary thyroid carcinoma; second primary cancer that has been cured and has no recurrence within 5 years; subjects who have clearly identified the origin of the metastatic lesion as being from a certain primary tumor);
• Mental illness or mental disorder, patients with poor compliance and inability to cooperate and describe treatment responses;
• Pregnant or lactating women;
• Other serious or uncontrollable diseases, or other conditions assessed by the researcher as not suitable for enrollment.