Multimodal thermal therapy (MTT), as an initiative integration of cryotherapy and radiofrequency heating, has been applied to treat various solid tumors. However, the feasibility and safety for MTT in the treatment of breast cancer is unknown. This prospective, open-label, single-arm phase II clinical study aimed to evaluate the efficacy and safety of MTT in the treatment of early-stage invasive breast cancer, and to explore the ablation-induced immune activating response.

Inclusion Criteria:

1. Female，age 18-80 years.
2. Invasive carcinoma confirmed by core biopsy.
3. Newly diagnosed breast cancer patients, without neoadjuvant therapy.
4. Imaging findings showed an unifocal breast tumor with a maximum diameter of 2 cm, with no distant metastasis, no calcification, no skin or nipple adhesion, and no invasion of chest wall.
5. The functional level of major organs must meet the following requirements: blood routine: neutrophil (ANC)≥1.5×10^9/L; platelet count (PLT) ≥ (PLT)≥90×10^9/L; hemoglobin (Hb) ≥90g/L; coagulation: international normalized ratio (INR) or prothrombin time (PT) ≤1.5×ULN; activated partial thromboplastin time (APTT) ≤1.5×ULN.

Exclusion Criteria:

1. Tumor involving skin, ulceration, inflammatory breast cancer patients.
2. Tumor involving the superficial layer of the skin.
3. KPS score < 70, or ECOG score > 2
4. Prior radiotherapy or prior use of investigational drugs or other immunosuppressive agents.
5. Heart, brain, lung, kidney and other vital organ failure.
6. Uncorrectable severe coagulopathy
7. Patient is pregnant or lactating
8. Poor glycemic control in diabetes
9. Patients with foreign body implantation around the tumor (such as breast augmentation injections or prostheses).
10. Patients with severe scars on the skin of the treatment area (protruding from the skin surface, width ≥ 1 cm)
11. 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).
12. 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.