What are the steps of a modified radical mastectomy in a female breast cancer patient?

Modified Radical Mastectomy: Surgical Steps

Modified radical mastectomy involves en bloc removal of the entire breast parenchyma with preservation of the pectoralis major muscle, combined with complete axillary lymph node dissection of levels I and II nodes. 1

Pre-Operative Requirements

• Rule out distant metastases with a metastatic screen as the mandatory first step before proceeding with modified radical mastectomy in patients with invasive breast cancer 1, 2
• Confirm invasive carcinoma histologically before surgery 1
• Evaluate disease extent with physical examination and imaging (mammography, ultrasound, or MRI) 1
• Never perform upfront surgery in stage IV disease—systemic therapy must be completed first (minimum 4-6 months of anthracycline and taxane-based chemotherapy) 1, 2

Surgical Technique Steps

Breast Tissue Removal

• Remove the entire breast parenchyma en bloc while preserving the pectoralis major muscle 1
• Ensure complete removal of breast tissue from skin flaps and chest wall 1
• The pectoralis minor muscle may be either preserved (Madden technique) or resected (Patey technique)—both approaches yield equivalent outcomes in terms of lymph node harvest, complications, and surgical difficulty 3

Axillary Dissection Approach

• Perform complete axillary lymph node dissection of levels I and II nodes 1
• Access the axilla through two approaches: first, dissect axillary contents from the subclavicular point to the pectoralis minor muscle after partially cutting the sternocostal origin of the pectoralis major muscle; second, approach from the posterior aspect of the pectoralis minor muscle to the lateral portion of the latissimus dorsi muscle 4
• Protect the long thoracic nerve and thoracodorsal nerve during dissection 5
• Consider protecting the anterior thoracic nerve and intercostobrachial nerve to prevent upper medial arm numbness, pain, and chest atrophy 5

Additional Considerations

• For stage II and IIIa cancers with central or medial tumors, parasternal lymph node dissection can be performed 4
• After lymph node dissection, resuture the detached edge of the sternocostal origin of the pectoralis major muscle to cover the parasternal region 4

Post-Operative Management

• All patients with confirmed lymph node involvement require post-mastectomy radiation therapy to the chest wall and regional lymph nodes (internal mammary chain, infra- and supraclavicular regions) 6, 1
• Escalate radiation dose to 66 Gy for patients <45 years of age, close or positive surgical margins, ≥4 positive lymph nodes after preoperative systemic treatment, or poor response to preoperative therapy 1, 2
• Immediate reconstruction is an option for standard breast cancer cases if patient preference, but delayed reconstruction is recommended for inflammatory breast cancer and high-risk scenarios 1
• Never perform immediate breast reconstruction in stage IV disease—reconstruction must be delayed until after completion of all therapy 2

Critical Pitfalls to Avoid

• Never omit post-mastectomy radiation when lymph node involvement is confirmed—this is mandatory for locoregional control 1, 2
• Never delay systemic therapy to pursue surgery in advanced disease, as chemotherapy is the primary treatment modality 1, 2
• Verify absence of residual microcalcifications with post-operative mammogram 2 months after surgery if microcalcifications were present initially 6
• Ensure adequate lymph node harvest (typically 19-20 nodes) to properly stage the disease 3