The goal of the study is to explore the efficacy and safety of hyperbaric oxygen in the neoadjuvant treatment of breast cancer patients

Inclusion Criteria:

1. Understand the study process, participate in the study voluntarily, and sign the informed consent form.

2. patients with histopathologically confirmed initial unilateral primary invasive breast cancer, occult breast cancer, Patients with histopathologically confirmed initial unilateral primary invasive breast cancer, with the exception of occult breast cancer, inflammatory breast cancer and eczema-like carcinoma

3. aged ≥ 18 years and ≤ 60 years, female

4. patients who meet the inclusion criteria for neoadjuvant therapy to receive neoadjuvant therapy for breast cancer (locally advanced) Patients with locally advanced breast cancer (AJCC stage III, except T3N1M0) or operable breast cancer, but without breast-conserving or axillary preservation (stage IIA-IIB and T3N1M0) or HER2 positive or TNBC with certain tumour load, or patients with clinical lymph node positivity or tumour size of 2cm and above.)

5. ECOG performance status 0-1. 6.

6. LVEF ≥ 55% 7.

7. Adequate bone marrow functional reserve: white blood cell count ≥3.0 x 109/L, neutrophil count ≥1.5 x 109/L; and 1.5 x 109/L; platelet count ≥ 100 x 109/L; haemoglobin ≥ 90 g/L;

8. AST, ALT ≤ 2.5 times the upper limit of normal value, alkaline phosphatase ≤ 2.5 times the upper limit of normal value.

   Total bilirubin ≤ 1.5 times the upper limit of normal value; serum creatinine ≤ 1.5 times the upper limit of normal value.

9. For non-menopausal or non-surgically sterilised female patients: during treatment and at least 7 months after the last dose of study treatment.

For non-menopausal or non-surgically sterilised female patients: consent to contraception during treatment and for at least 7 months after the last dose of study treatment.

Exclusion Criteria:

1. Contraindication to hyperbaric oxygen therapy: untreated pneumothorax. Concurrent use of disulfiram. concomitant administration of anti-tumour drugs such as bleomycin, cisplatin, adriamycin concomitant administration of antineoplastic drugs such as bleomycin, cisplatin, adriamycin. Premature and/or low body mass neonates. Lung disease (severe chronic obstructive pulmonary disease).

   Diseases of the lungs (severe chronic obstructive airway disease, herpetic lung disease, acute or chronic lung infections, uncontrolled asthma, uncontrolled diarrhoea).

   controlled asthma, untreated pneumothorax), history of previous middle ear surgery, middle ear disease (eustachian tube Dysfunction of the eustachian tube, recurrent episodes of vertigo), ocular disease (retinal detachment).

2. previous hyperbaric oxygen therapy.

3. distant metastases, including lymph node metastases to the contralateral breast and mediastinum.

4. other malignant tumours within the last two years, except for radically treated basal or squamous cell carcinoma of the skin or CIS of the cervix.

   Tumour.

5. pregnancy or lactation

6. uncontrolled hypertension, cardiac, hepatic, renal related disease or other medical or psychiatric conditions.

7. major surgical procedure unrelated to breast cancer within 4 weeks prior to randomisation, or the patient has not fully recovered from such procedure; or has not fully recovered from such surgical intervention.

8. serious or uncontrolled infections that may interfere with study treatment or assessment of study results, including but not limited to Serious or uncontrolled infections that may interfere with study treatment or the evaluation of study results, including but not limited to active hepatitis virus infection, human immunodeficiency virus (HIV) antibody positivity, and pulmonary infections.

9. recent history of thromboembolism and taking full dose anticoagulant medication.

10. any other condition that, in the opinion of the investigator, makes the patient unsuitable for participation in the study