Mastectomy — How It Works, Benefits & Recovery — Procedure Guide, Recovery & Risks | MyMedicPlus

Mastectomy is the surgical removal of one or both breasts, performed primarily to treat or prevent breast cancer. It is one of the most widely performed oncological operations worldwide, with approximately 250,000 mastectomies performed annually in the United States alone. Several distinct surgical variants exist, each suited to different tumour characteristics, patient anatomy, and reconstruction goals. Total (simple) mastectomy removes the entire breast — skin, nipple-areolar complex, and all breast tissue — without removing axillary lymph nodes. Modified radical mastectomy additionally removes level I and II axillary lymph nodes while preserving the pectoralis muscles, combining cancer control with nodal staging. Nipple-sparing mastectomy (NSM) preserves the nipple-areolar complex when the tumour is sufficiently distant from the nipple and a sub-nipple biopsy confirms clear margins — offering the best cosmetic outcome for reconstruction. Skin-sparing mastectomy preserves the majority of the breast skin envelope, facilitating immediate reconstruction while removing all glandular tissue. Prophylactic (risk-reducing) mastectomy is performed in high-risk women without cancer — typically BRCA1/2 mutation carriers — to reduce future cancer risk by up to 95%. The oncological team tailors the mastectomy type to the individual based on tumour size, location, biological subtype, patient risk factors, and desire for reconstruction, in a multidisciplinary shared-decision process.

Mastectomy is indicated when breast-conserving surgery (lumpectomy with radiation) is not feasible, not preferred by the patient, or when the expected oncological outcome is superior with complete breast removal. Specific indications include: large tumours relative to breast volume where clear margins cannot be achieved with acceptable cosmesis; multifocal or multicentric disease in multiple quadrants of the breast; inflammatory breast cancer after neoadjuvant chemotherapy; inability to receive post-operative radiotherapy (collagen-vascular disease, prior chest radiation, pregnancy); local recurrence after prior breast-conserving surgery and radiation; and patient preference for mastectomy over lumpectomy. Prophylactic mastectomy is offered to women with BRCA1 or BRCA2 pathogenic gene variants, where lifetime breast cancer risk exceeds 60–80%, and to women with strong family history or other high-risk hereditary syndromes (PALB2, CHEK2, ATM). Lobular carcinoma in situ (LCIS) with high-risk features may also warrant prophylactic treatment. The decision between mastectomy and breast-conserving surgery is made after multidisciplinary team discussion, and for equivalent-stage tumours, long-term survival is equal between the two approaches in randomised trials including the NSABP B-06 trial — making patient preference and quality-of-life considerations central to the decision.

Mastectomy is performed under general anaesthesia, with the patient supine and the ipsilateral arm extended. For total or modified radical mastectomy, an elliptical incision is drawn incorporating the nipple-areolar complex and any prior biopsy scar to ensure complete excision of biopsy tract skin. Skin flaps — thin layers of skin with 5–10 mm of subcutaneous fat — are raised over the entire breast footprint from clavicle to inframammary fold and from the sternal edge to the anterior axillary line. All breast glandular tissue is dissected off the underlying pectoralis major muscle fascia, removing the entire specimen en bloc with the nipple and skin ellipse. In skin-sparing mastectomy, only the nipple-areolar complex is excised and the remaining skin preserved for reconstruction. In nipple-sparing mastectomy, a periareolar, lateral, or inframammary fold incision is used to preserve the entire nipple-areolar complex after sub-nipple tissue is sent for frozen section to confirm clear margins. For modified radical mastectomy, axillary level I–II lymph node dissection is added, removing the fatty-nodal tissue medial and lateral to the pectoralis minor while protecting the thoracodorsal nerve, long thoracic nerve, and axillary vein. Sentinel lymph node biopsy using a radioactive tracer and blue dye is performed where indicated to minimise axillary dissection in node-negative patients. One or two closed suction drains are placed before layered wound closure. Immediate reconstruction — using tissue expanders, direct-to-implant, or autologous flap techniques — can be performed by a plastic surgery team at the same operative sitting. Operative time for mastectomy alone is 1.5–3 hours; reconstruction extends this to 4–8 hours.

Mastectomy provides definitive locoregional tumour control with local recurrence rates below 5% for early-stage breast cancer treated with appropriate adjuvant systemic therapy. For equivalent-stage disease, overall survival is the same as lumpectomy plus radiation, established in multiple randomised controlled trials over 20-year follow-up. The key benefits over breast-conserving surgery are elimination of the need for post-operative radiotherapy in many patients, lower local recurrence in high-risk biologically aggressive tumours, and avoidance of repeat surgery for positive margins — a situation arising in 20–30% of lumpectomy procedures. For BRCA1/2 carriers, prophylactic bilateral mastectomy reduces the relative risk of developing breast cancer by over 90%, converting a lifetime risk of 70–80% to under 5–10%. Immediate breast reconstruction at the time of mastectomy achieves patient satisfaction rates of over 80% for cosmetic and psychological outcomes in well-selected patients, significantly reducing the psychological impact of losing a breast. Nipple-sparing mastectomy with implant reconstruction, in appropriate candidates, produces cosmetic results that are indistinguishable from breast augmentation in many cases. Mastectomy also avoids repeated screening uncertainty in women with dense breasts and enables definitive treatment in a single operative procedure.

Seroma formation in the surgical cavity and axilla is the most common complication, occurring in 30–60% of mastectomy patients. Seromas are managed by repeated aspiration in clinic and resolve spontaneously in the majority within 4–8 weeks. Haematoma requiring surgical drainage occurs in 2–3%. Wound infection affects approximately 5–10% of patients; smoking and obesity are major risk factors. Skin flap necrosis — partial or full thickness loss of the skin flap — occurs in smokers or when flaps are raised too thin, and may require wound debridement and delayed closure. Lymphoedema of the ipsilateral arm is the most significant long-term morbidity when full axillary lymph node dissection is performed, affecting 15–25% of patients; sentinel node biopsy reduces this risk to under 5%. Intercostobrachial nerve damage during axillary dissection causes numbness, tingling, or dysaesthesia of the medial upper arm in up to 70% of patients; most improve gradually over 12–18 months. Chest wall and anterior shoulder numbness from division of skin sensory branches is permanent in most patients. Phantom breast sensations and post-mastectomy pain syndrome — chronic neuropathic pain at the mastectomy scar — affect 20–30% of patients to varying degrees. Shoulder stiffness and restricted arm movement are mitigated by early physiotherapy beginning at one week. Reconstruction-specific complications include capsular contracture, implant infection (1–3%), and in rare cases Breast Implant-Associated Anaplastic Large Cell Lymphoma (BIA-ALCL) with textured implants.

After mastectomy, closed suction drains remain for 1–2 weeks and are removed in clinic when daily output falls below 30 mL. Hospital discharge is typically after 1–3 days; immediate reconstruction patients stay 2–4 days. Post-operative pain is managed with regular paracetamol, NSAIDs, and short-course oral opioids if required. A soft post-mastectomy bra or surgical vest supports the wound during the first 4–6 weeks. Shoulder and arm physiotherapy — beginning with pendulum exercises from day 1 and progressing to full range of motion by 4–6 weeks — is essential to prevent frozen shoulder and lymphoedema. Heavy lifting above 2–3 kg is avoided for 4–6 weeks. Return to desk work is typically at 3–4 weeks; more physical roles at 6–8 weeks. Adjuvant chemotherapy commences 3–4 weeks post-operatively when indicated; post-mastectomy radiotherapy (when required for T3/T4 tumours or 4+ positive nodes) begins at 4–8 weeks after wound healing. Lymphoedema precautions — avoiding venepuncture, blood pressure measurements, and tight garments on the operated arm — are maintained lifelong. Women undergoing reconstruction follow an additional plastic surgery protocol. Prosthetic breast fitting can be arranged 4–6 weeks post-operatively for patients without reconstruction, and oncology nurses provide specialist support for body image and psychological adjustment throughout the process.