This clinical trial aims to determine whether conventional surgery or endoscopic surgery results in better recovery of breast skin sensation in women with early-stage breast cancer undergoing nipple-sparing mastectomy with prepectoral implant reconstruction. Furthermore, the study will compare the safety, aesthetic outcomes, and quality of life associated with the two surgical approaches. The study seeks to address the following primary research questions:

Does conventional surgery lead to superior recovery of breast skin sensation at 6 months postoperatively compared with endoscopic surgery?

What are the differences between the two surgical approaches in terms of complication rates, aesthetic outcomes, and patient-reported quality of life?

Researchers will compare conventional nipple-sparing mastectomy with endoscopic nipple-sparing mastectomy to determine which procedure better preserves postoperative breast sensation.

Participants will:

Be randomly assigned to undergo either conventional or endoscopic surgery.

Have breast skin sensation measured preoperatively and at multiple postoperative follow-up visits using a standardized assessment tool.

Complete validated questionnaires regarding breast satisfaction and quality of life preoperatively and during multiple follow-up visits.

Attend scheduled follow-up visits to monitor for complications and to evaluate the long-term appearance and health of the reconstructed breast.

Inclusion Criteria:

1. Female patients aged 18 to 70 years.
2. Unilateral breast cancer confirmed by preoperative pathology.
3. Scheduled to undergo nipple-sparing mastectomy (NSM) with immediate prepectoral implant-based breast reconstruction.
4. Invasive carcinoma with a maximum tumor diameter ≤ 5 cm, or ductal carcinoma in situ (DCIS).
5. Preoperative imaging assessment confirms a distance of ≥ 1 cm between the lesion and the nipple-areola complex (NAC).
6. No clinical, radiological, or pathological evidence of tumor invasion into the NAC, skin, or pectoralis major muscle. The tumor must be confined within the glandular tissue.
7. No evidence of distant metastasis (M0).
8. Clinically node-negative (cN0) as assessed by preoperative examination.
9. No history of neoadjuvant chemotherapy or radiotherapy prior to surgery.
10. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
11. Willing and able to understand the study procedures, provide written informed consent, demonstrate good compliance, and agree to participate in follow-up evaluations.
12. The principal surgeon must have experience in performing at least 30 cases of NSM combined with implant-based reconstruction.

Exclusion Criteria:

1. Diagnosis of Paget's disease of the breast, recurrent breast cancer, or a history of prior thoracic radiation therapy.
2. Evidence of tumor invasion into the skin (including inflammatory breast cancer), nipple-areola complex, or pectoralis major muscle.
3. Pregnancy or lactation at the time of enrollment.
4. Requirement for re-excision following a prior breast lump biopsy, or a history of any previous breast surgery (including but not limited to augmentation mammoplasty, breast reduction, lumpectomy, etc.).
5. Breast size exceeding a D-cup.
6. Body mass index (BMI) > 30 kg/m².
7. Grade III ptosis (severe breast drooping where the nipple is positioned below the inframammary fold).
8. Pre-existing nipple-areolar complex deformities (e.g., nipple inversion, areolar hypoplasia), active skin conditions of the breast (e.g., eczema, dermatitis, infection, ulceration), or significant scarring compromising the surgical site.
9. Severe systemic comorbidities (e.g., immunosuppression, uncontrolled diabetes mellitus, severe cardiopulmonary dysfunction, coagulopathy or bleeding diathesis, contraindications to general anesthesia).
10. Known hypersensitivity or allergy to silicone gel implants, or to anesthetic agents/antibiotics used perioperatively.
11. Pre-existing neurological disorders (e.g., diabetic peripheral neuropathy, Parkinson's disease, polyneuritis, spinal cord injury) or chronic use of medications known to affect neurological/sensory function (e.g., antidepressants, antiepileptics).
12. Current heavy smoking (>20 cigarettes per day).
13. Current alcohol abuse or substance addiction.
14. Concurrent or history of other active malignancies
15. Anticipated poor compliance with follow-up protocols or inability to complete scheduled postoperative evaluations.