The goal of this observational study is to learn about the effects of metronomic chemotherapy in advanced breast cancer patients. The main question it aims to answer is:

How effective is metronomic chemotherapy in advanced breast cancer? Specific benefit groups of metronomic chemotherapy.

Inclusion Criteria:

1. Females, >18 years old;
2. Diagnosed with advanced breast cancer when using metronomic chemotherapy;
3. At least one clinical evaluation, including physical examination and imaging, according to the instructions of the supervising physician during the use of metronomic chemotherapy. Examinations include ultrasound, computed tomography, and magnetic resonance imaging;
4. Metronomic chemotherapy can be used alone, and patients who use it in combination with other drugs can also be included;
5. The clinical pathological information that needs to be collected is complete.

Exclusion Criteria:

1. Taking the drug for less than 2 weeks;
2. losing follow-up after taking the therapy;
3. The patient's breast cancer was still in the early stage when taking the therapy.

Advanced breast cancer taking metronomic chemotherapy