1. To explore the predictive value of ctDNA in HER2 positive breast cancer neoadjuvant therapy population; 2. To evaluate the prognostic value of ctDNA in HER2 positive breast cancer neoadjuvant therapy population.
Women with breast cancer diagnosed clinically and pathologically, aged 18-75 years;
ECOG performance score is 0-1;
Histologically confirmed as early or locally advanced invasive breast cancer: the diameter of the primary tumor is more than 2 cm, and HER2 is positive (confirmed by IHC or FISH).
The patient did not receive any treatment for breast cancer before enrollment;
Patients with known metastatic or stage IV breast cancer;
There are other untreated malignant tumors other than breast cancer;
Patients with one or more serious systemic diseases that, in the eyes of researchers, can impair their ability to complete research;
According to the researchers' assessment, there may be other factors that could force the subjects to terminate the study midway, such as suffering from other serious illnesses (including mental illnesses) that require concurrent treatment, severe abnormal laboratory test values, family or social factors, which may affect the safety of the subjects or the collection of experimental data.