Residency · Residency · General Surgery
Surgical Management of Invasive Breast Cancer
Overview
Surgery remains the cornerstone of curative treatment for invasive breast cancer. Two primary options exist: breast-conserving surgery (BCS/lumpectomy) with radiation, or mastectomy. The oncologic equivalence of BCS plus radiation and mastectomy was established by the landmark NSABP B-06 and Milan I trials. Treatment planning is multidisciplinary, involving surgery, medical oncology, radiation oncology, pathology, and radiology.
Preoperative Evaluation
The preoperative workup begins with core needle biopsy and pathologic assessment including histology, grade, ER/PR/HER2 status, and Ki-67. Bilateral diagnostic mammography and breast ultrasound are obtained. Breast MRI is selectively used for extent of disease assessment and should be considered for lobular carcinoma, dense breasts, discrepancies between clinical and imaging findings, and young patients, though its routine use is controversial as MRI increases mastectomy rates without proven survival benefit. Axillary assessment includes ultrasound with FNA or CNB of suspicious nodes. Genetic testing is pursued when indicated by young age, family history, or triple-negative histology. Staging imaging (CT, bone scan, PET-CT) is reserved for stage III disease or symptomatic patients and is not routinely performed for early-stage disease.
Breast-Conserving Surgery (BCS/Lumpectomy)
Principles
The principles of breast-conserving surgery are complete excision of the tumor with negative margins, followed by whole-breast radiation therapy to achieve oncologic equivalence to mastectomy, while preserving a cosmetically acceptable result with an appropriate tumor-to-breast ratio.
Margin Assessment
The current standard for invasive cancer is "no ink on tumor," as established by the 2014 SSO-ASTRO consensus. A negative margin is defined as no tumor cells at the inked resection edge, and wider margins do not further reduce local recurrence. For a DCIS component, a 2 mm margin is recommended per the 2016 SSO-ASTRO-ASCO consensus. Intraoperative specimen imaging with mammography or ultrasound is used to assess adequacy. Routine cavity shave margins -- the practice of shaving the cavity walls -- reduces re-excision rates by approximately 30%, as demonstrated by the SHAVE trial. Orienting sutures or clips are placed on the specimen to allow directed re-excision if margins are found to be positive.
Contraindications to BCS
Absolute contraindications include inability to achieve negative margins, multicentric disease involving multiple quadrants, prior radiation to the breast, and pregnancy (because radiation is contraindicated, although surgery itself can be performed). Relative contraindications include a large tumor-to-breast ratio, connective tissue disease such as scleroderma or SLE (which increases radiation complications), extensive microcalcifications, and strong patient preference for mastectomy.
Oncoplastic Breast Surgery
Oncoplastic breast surgery combines oncologic resection with plastic surgery techniques to improve cosmesis. It allows wider excisions of up to 30-50% of breast volume while maintaining breast shape. Techniques include volume displacement (local tissue rearrangement and reduction mammoplasty patterns) and volume replacement (local flaps and lipofilling). Symmetrizing surgery on the contralateral breast may be needed. Oncoplastic approaches expand the indication for BCS in patients with larger tumors or challenging tumor locations.
<image>Oncoplastic breast surgery techniques showing volume displacement approaches including therapeutic mammoplasty and rotation flap with corresponding pre- and post-operative appearances</image>
Mastectomy
Types
Simple (total) mastectomy removes all breast tissue including the nipple-areola complex but does not include axillary dissection. Modified radical mastectomy combines simple mastectomy with axillary lymph node dissection of levels I and II. Skin-sparing mastectomy preserves the breast skin envelope while removing the nipple-areola complex and breast tissue, facilitating immediate reconstruction. Nipple-sparing mastectomy preserves both the skin and nipple-areola complex, with subareolar tissue sent for frozen section analysis. Nipple-sparing mastectomy is appropriate for prophylactic procedures and select invasive cancers (tumor more than 2 cm from the nipple-areola complex without skin or nipple involvement), and is contraindicated in inflammatory breast cancer, clinical involvement of the nipple-areola complex, and Paget's disease. Oncologic safety data for nipple-sparing mastectomy is reassuring with appropriate patient selection. The radical mastectomy (Halsted), which includes pectoralis major resection, is of historical significance and is rarely performed today.
Indications for Mastectomy
Indications include patient preference, multicentric disease, inability to achieve negative margins with BCS, contraindication to radiation therapy, a large tumor-to-breast ratio not amenable to oncoplastic techniques, BRCA mutation carrier status (bilateral mastectomy for risk reduction), and inflammatory breast cancer (modified radical mastectomy after neoadjuvant chemotherapy).
Breast Reconstruction
Breast reconstruction should be offered to all mastectomy patients, as mandated by the Women's Health and Cancer Rights Act. Immediate reconstruction, performed at the time of mastectomy, yields better cosmetic outcomes, higher patient satisfaction, and greater psychological benefit, and does not delay adjuvant chemotherapy when properly coordinated. Delayed reconstruction is performed after completion of all treatments and is indicated when radiation is planned (relative indication), for advanced disease, or by patient preference. Reconstruction types include implant-based approaches (tissue expander followed by permanent implant, or direct-to-implant), autologous tissue flaps (TRAM flap, DIEP flap, or latissimus dorsi flap), and hybrid approaches combining implant and autologous tissue. Post-mastectomy radiation may compromise implant reconstruction through capsular contracture and implant loss.
<image>Types of mastectomy showing simple mastectomy, skin-sparing mastectomy, and nipple-sparing mastectomy with the extent of tissue removed and skin preservation in each technique</image>
Neoadjuvant Chemotherapy (NAC)
Indications
Neoadjuvant chemotherapy is indicated for locally advanced breast cancer (stage III), large tumors relative to breast size to enable BCS, inflammatory breast cancer, triple-negative and HER2-positive cancers (which have high response rates), and to assess in vivo tumor response for guiding adjuvant therapy decisions.
Surgical Considerations After NAC
Pathologic complete response (pCR) is defined as no residual invasive disease in the breast and axilla. pCR rates are 40-60% for triple-negative and HER2-positive subtypes, and 5-15% for ER-positive/HER2-negative disease. BCS is feasible after NAC if negative margins are achievable, the cancer is not inflammatory, and there are no other contraindications. The tissue marker clip placed at the time of diagnosis is essential for localizing the original tumor bed. Imaging re-assessment with mammography, ultrasound, and potentially MRI is performed before surgery to evaluate residual disease. Pathologic response guides adjuvant therapy: residual disease after NAC in triple-negative breast cancer is treated with capecitabine (CREATE-X trial), and residual disease after NAC in HER2-positive breast cancer is treated with T-DM1 (KATHERINE trial).
Special Histologic Subtypes
Invasive Lobular Carcinoma (ILC)
Invasive lobular carcinoma is the second most common histologic type, comprising 10-15% of breast cancers. It is often multifocal or multicentric with a diffuse infiltrating pattern. Mammographic sensitivity is lower, as it may appear only as subtle distortion or asymmetry. Breast MRI may be more useful for extent of disease assessment. ILC has a higher rate of positive margins and re-excision compared to ductal carcinoma. BCS with negative margins remains appropriate, and oncoplastic techniques may be helpful.
Inflammatory Breast Cancer
Inflammatory breast cancer is a clinical diagnosis characterized by erythema, edema (peau d'orange), and warmth involving more than one-third of the breast skin. Skin biopsy shows dermal lymphatic invasion. Treatment is trimodal: neoadjuvant chemotherapy, modified radical mastectomy, and radiation. BCS is contraindicated. Sentinel lymph node biopsy is controversial, and axillary lymph node dissection is standard.
Phyllodes Tumor
Phyllodes tumor is a fibroepithelial neoplasm classified as benign, borderline, or malignant. Treatment is wide local excision with 1 cm margins for borderline and malignant tumors. Simple mastectomy is performed if adequate margins cannot be achieved. Lymph node dissection is not indicated because phyllodes tumors spread hematogenously rather than via lymphatics. Radiation for malignant phyllodes with close or positive margins remains controversial.
<image>Clinical and imaging presentation of inflammatory breast cancer showing skin erythema, peau d'orange appearance on clinical examination, and skin thickening with enhancement on breast MRI</image>
Surgical Management of the Male Breast
Male breast cancer typically presents as a painless subareolar mass. Modified radical mastectomy is the standard surgical treatment, as BCS is rarely feasible due to limited breast tissue. Sentinel lymph node biopsy is performed for clinically node-negative disease. Systemic therapy follows the same principles as female breast cancer, and most male breast cancers are ER-positive.
Adjuvant Radiation Therapy
After BCS
Whole-breast radiation therapy is standard after BCS. Hypofractionated WBRT (40 Gy in 15 fractions) is the current standard, supported by the START-B and FAST-Forward trials. A boost to the tumor bed is considered for high-risk features such as young age, close margins, and high grade. Accelerated partial breast irradiation is an option for select low-risk patients with small, ER-positive, node-negative tumors. Omission of radiation may be considered in highly selected elderly patients (over 70 years, T1, ER-positive, node-negative, on endocrine therapy), as supported by the PRIME II and CALGB 9343 trials.
Post-Mastectomy Radiation Therapy (PMRT)
Post-mastectomy radiation is indicated for T3-4 tumors, positive margins, and 4 or more positive lymph nodes. Its use in the setting of 1-3 positive lymph nodes is controversial, with some recommending it based on other high-risk features. PMRT impacts reconstruction timing and method selection.
Clinical Pearls
BCS plus radiation and mastectomy are oncologically equivalent for early-stage breast cancer, and patient preference and body image concerns should be respected. "No ink on tumor" is the standard for invasive cancer margins, and re-excision should not be performed for close but negative margins. Cavity shave margins reduce re-excision rates and should be considered routine. A tissue marker clip must be placed at diagnosis, especially if neoadjuvant chemotherapy is planned, to ensure the original tumor bed can be located. Nipple-sparing mastectomy is oncologically safe in appropriately selected patients and significantly improves body image and satisfaction. Inflammatory breast cancer is a clinical diagnosis, and the skin should always be biopsied; BCS is contraindicated. Oncoplastic techniques expand the indications for BCS, and collaboration with plastic surgery is valuable for complex cases.
References
- Fisher B, et al. Twenty-year follow-up of a randomized trial comparing total mastectomy, lumpectomy, and lumpectomy plus irradiation for the treatment of invasive breast cancer (NSABP B-06). N Engl J Med. 2002;347(16):1233-1241.
- Moran MS, et al. SSO-ASTRO consensus guideline on margins for breast-conserving surgery with whole-breast irradiation in stages I and II invasive breast cancer. Ann Surg Oncol. 2014;21(3):704-716.
- Chagpar AB, et al. A randomized, controlled trial of cavity shave margins in breast cancer (SHAVE). N Engl J Med. 2015;373(6):503-510.
- Masuda N, et al. Adjuvant capecitabine for breast cancer after preoperative chemotherapy (CREATE-X). N Engl J Med. 2017;376(22):2147-2159.
- von Minckwitz G, et al. Trastuzumab emtansine for residual invasive HER2-positive breast cancer (KATHERINE). N Engl J Med. 2019;380(7):617-628.
