To establish a predicting system on axillary lymph node metastasis based on peripheral blood CK19mRNA and contrast-enhanced ultrasound.

The feasibility and predictive accuracy of peripheral blood CK19mRNA and contrast-enhanced ultrasound of axillary lymph nodes metastasis in breast cancer were verified by the data of specimen bank; to establish the evaluation system of predicting the lymph node status based on CK19 and CEUS, validate the sensitivity, specificity, negative predictive value, positive predictive value and ROC curve of the system model and use Youden index, negative likelihood ratio, positive likelihood ratio to evaluate the diagnostic efficiency.

Inclusion Criteria:

1. female, age 18~70 years old
2. the test group should be in accordance with the pathological diagnosis of breast cancer, the clinical stage of breast cancer (stage cTis, cI, cII and cT3N1M0), the initial treatment to receive surgical treatment. Complete preoperative clinical diagnosis data, including the ipsilateral axillary lymph node CEUS data and peripheral blood sample; The negative-control group should comply with the pathological diagnosis, breast adenosis, fibrocystic lesions, breast cysts and other benign lesions, with complete preoperative clinical data, also including ipsilateral axillary lymph node CEUS data and peripheral blood sample

Exclusion criteria:

1. metastatic breast cancer, inflammatory breast disease, surgery without lymph node staging
2. pregnancy or lactation
3. patients with hematopoietic system disease or cancer, autoimmune diseases
4. preservation of substandard peripheral blood samples.

Operable breast cancer patients (clinical stage: cTis, cI, cII, cT3N1M0)

1year