Ablative therapy, as a local treatment modality for tumors, has an immune activating effect. To explore the synergistic effect of microwave ablation combined with PD-1 inhibitors, this prospective, open-label, multi-cohort, single-center clinical study was conducted. To compare the feasibility and safety of preoperative microwave ablation alone, with or without camrelizumab in patients with early newly diagnosed breast cancer.

Inclusion Criteria:

1. Female.

2. Age 20-65 years.

3. Invasive carcinoma confirmed by core biopsy.

4. Newly diagnosed breast cancer patients, without adjuvant therapy.

5. Imaging findings showed a single breast tumor with a maximum diameter of 3 cm, no distant metastasis, and no invasion of the skin and chest wall.

6. Systematic ultrasound is able to visualize lesions.

7. Surgical treatment was planned.

8. The functional level of major organs must meet the following requirements:

   1. blood routine: neutrophil (ANC) ≥ 1.5 × 109/L; platelet count (PLT) ≥ 90 × 109/L; hemoglobin (Hb) ≥ 90 g/L;
   2. blood biochemistry: total bilirubin (TBIL) ≤ upper limit of normal (ULN); alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 1.5 × ULN; alkaline phosphatase ≤ 2.5 × ULN; blood urea nitrogen (BUN) and creatinine (Cr) ≤ 1.5 × ULN;
   3. coagulation: international normalized ratio (INR) or prothrombin time (PT) ≤ 1.5 × ULN; activated partial thromboplastin time (APTT) ≤ 1.5 × ULN.
   4. Heart: left ventricular ejection fraction (LVEF) ≥ 50% as assessed by echocardiography (ECHO) or multigated acquisition (MUGA).
   5. Thyroid function: thyroid stimulating hormone (TSH) ≤ ULN; if abnormal, T3 and T4 levels should be investigated, and normal T3 and T4 levels can be included.
   6. Urinalysis: urine protein < 2 +, if urine protein ≥ 2 +, 24-hour urine protein quantification must show protein ≤ 1 g.

9. Voluntarily participate in this study, sign informed consent, have good compliance and are willing to cooperate with follow-up.

Exclusion Criteria:

1. Tumor involving skin, ulceration, inflammatory breast cancer patients
2. Fatty breast cancer.
3. Tumors on the deep surface of areolar region
4. KPS score < 70, or ECOG score > 2
5. Patients with a history of concomitant collagen connective tissue disease, or any active autoimmune disease or autoimmune disease.
6. Prior radiotherapy or prior use of investigational drugs or other immunosuppressive agents
7. Heart, brain, lung, kidney and other vital organ failure, liver and kidney dysfunction;
8. Uncorrectable severe coagulopathy
9. Patient is pregnant or lactating
10. Poor glycemic control in diabetes
11. Patients with foreign body implantation around the tumor
12. Patients with severe scars on the skin of the treatment area (protruding from the skin surface, width ≥ 1 cm)
13. History of chronic immunosuppression, prior immunotherapy, recent vaccination (< 4 weeks)
14. Human immunodeficiency virus (HIV) infection, active hepatitis B (hepatitis B indicates antigen positive and HBV DNA ≥ 500 IU/ml), hepatitis C (hepatitis C antibody positive and HCV-RNA above the lower limit of detection of the analytical method).
15. Concurrent medical conditions that, in the judgment of the investigator, would jeopardize the subject's safety, could confound the study results, or affect the subject's completion of this study.

Available from the corresponding author upon reasonable request