New study aims to find which mastectomy method saves more breast sensation

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

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.