This study aims to enroll refractory breast cancer patients. Patient-derived organoid will be established, and drug sensitivity test will be conducted to intervene in the selection of clinical treatment plans. Efficacy evaluation and prognosis analysis will also be conducted. It is hoped that this study will provide a basis for the development of personalized treatment plans.

Forty patients with refractory breast cancer who met the inclusion criteria were enrolled in the study after signing an informed consent form. Tumor samples were obtained through clinical puncture, and qualified samples were subjected to organoid modeling. Perform drug sensitivity test on the established breast cancer organoids. The drugs used are all that have been marketed and applied in clinical practice. According to the results of organoid drug sensitivity analysis, the patient received a treatment plan with relatively sensitive drugs. Follow up prognostic data and relevant clinical information of enrolled patients, conduct statistical analysis on the consistency between drug sensitivity test results and patient treatment response, and evaluate the clinical effectiveness of treatment plans guided by organoid drug sensitivity results.

Inclusion Criteria:

1. Female, aged ≥ 18 years and ≤ 75 years old;
2. Breast cancer confirmed by histology or cytology;
3. One of the following two conditions shall be met: a) Operable breast cancer: Recurrent progression during adjuvant therapy; or the time from initial treatment to the onset of disease progression is less than or equal to 2 years; b) Non-operable breast cancer: patients who have changed two line treatment plans within 6 months;
4. Being able to obtain sufficient fresh tissue specimens for organoid establishment through puncture;
5. Expected survival time ≥ 3 months;
6. The patient voluntarily joined this study and signed an informed consent form (ICF), with good compliance and cooperation in follow-up.

Exclusion Criteria:

1. Pregnant and lactating women;
2. Patients who have clinically significant (i.e. active) heart disease (such as congestive heart failure, symptomatic coronary artery disease, arrhythmia, etc.) or myocardial infarction within the past 12 months;
3. Individuals with a history of abuse of psychotropic drugs who are unable to quit or have mental disorders;
4. The researchers believe that patients are not suitable for inclusion.