Evaluation of the Safety and Efficacy of Single-Port Robot-Assisted Endoscopic Breast-Conserving Surgery and Nipple-sparing Matectomy With Reconstruction in Early-Stage Breast Cancer Patients

Inclusion Criteria: 1. Female patients aged 18 to 80 years; 2. Histopathologically confirmed invasive breast cancer or ductal carcinoma in situ (DCIS); 3. Clinical stage I-II for breast-conserving surgery, or clinical stage I-III for subcutaneous mastectomy with immediate prosthetic reconstruction; 4. Planned to undergo breast-conserving surgery or subcutaneous mastectomy with immediate prosthetic reconstruction; 5. For breast-conserving surgery: maximum tumor diameter ≤ 3 cm, with a favorable tumor-to-breast volume ratio for breast conservation; 6. For subcutaneous mastectomy with immediate prosthetic reconstruction: willingness and appropriate indication for prosthetic reconstruction, with moderate breast volume; 7. Eastern Cooperative Oncology Group (ECOG) performance status score of 0-1; 8. American Society of Anesthesiologists (ASA) physical status classification I-III; 9. Adequate vital organ function meeting the following criteria: Hematology: absolute neutrophil count ≥ 1.5 × 10⁹/L, platelet count ≥ 90 × 10⁹/L, hemoglobin ≥ 90 g/L; Liver function: total bilirubin ≤ 1.5 × upper limit of normal (ULN), ALT and AST ≤ 2.5 × ULN; Renal function: creatinine ≤ 1.5 × ULN; Coagulation function: INR ≤ 1.5, APTT ≤ 1.5 × ULN; 10. Voluntary participation with written informed consent signed. Exclusion Criteria: 1. Prior history of breast surgery (excluding biopsy procedures); 2. Prior history of chest wall radiotherapy; 3. Pregnant or lactating women; 4. Concurrent malignancy (excluding adequately treated basal cell carcinoma of the skin or carcinoma in situ of the cervix); 5. Severe cardiopulmonary dysfunction precluding tolerance to general anesthesia; 6. Severe hepatic or renal insufficiency; 7. Coagulation disorders or ongoing anticoagulant therapy that cannot be discontinued; 8. Active infection, particularly in the breast region; 9. Allergy or intolerance to silicone implant materials (for patients undergoing prosthetic reconstruction); 10. Severe breast ptosis or excessively large breast volume (for patients undergoing prosthetic reconstruction); 11. Presence of any contraindication to surgery, or any condition that the investigator deems unsuitable for study participation.