Mastectomy (complete removal of the tissue of the breast) is one option for the surgical treatment of breast cancer and surgical option for breast cancer risk reduction. But with advances in surgical skills and chemotherapy now breast conservation has almost replaced the mastectomy. However mastectomy is still an option with certain indications.

When To Do Mastectomy?

Breast conservation contraindicated or unsuccessful — The criteria that preclude breast conservation are presented here briefly and addressed in detail elsewhere.

Inflammatory breast cancer (IBC). For patients with IBC, the standard of care is neoadjuvant chemotherapy followed by modified radical mastectomy and postmastectomy radiation therapy.

Multicentric disease with two or more primary tumors in separate quadrants of the breast. However, ongoing research is assessing techniques that could permit breast conservation for selected multicentric diseases with a satisfactory cosmetic outcome.  Diffuse suspicious microcalcifications on mammography such that the extent of disease is not clearly evident.

A history of prior therapeutic radiation that included a portion of the affected breast, which, with the addition of whole breast radiation therapy (WBRT), would result in an excessively high total radiation dose to the chest wall. This includes patients who had prior breast radiation as well as those who received chest wall radiation for other reasons, such as mantle radiation for Hodgkin's lymphoma. Pregnancy is an absolute contraindication to the use of breast irradiation; however, there are some patients in the later stages of pregnancy who, following surgery and/or chemotherapy, may safely defer radiation to after delivery, allowing for breast conservation.

Inability to clear persistently positive resection margins after reasonable attempts at re-excision. Breast conservation contraindicated or unsuccessful, as an example, large tumor size in relation to breast size. Although neoadjuvant systemic treatment has the potential to downstage large tumors and improve the chances for successful breast-conserving surgery, insufficient response to neoadjuvant chemotherapy or endocrine therapy requires mastectomy. Alternatively, oncoplastic surgery may permit breast conservation in this scenario.

Patient preference - Some patients may choose to have a mastectomy rather than breast-conserving therapy for various reasons, including a desire to avoid postoperative radiation, further screening, or biopsies. 

When both breast-conserving surgery and mastectomy are clinically and oncologically acceptable, patients should be presented with the advantages and disadvantages of both approaches. This should include discussion of cosmetic concerns because breast-conserving surgery may result in unacceptable cosmetic results if the patient has a small amount of breast tissue. Discussion should also include a realistic risk assessment of the likelihood of a recurrence or second primary as studies have shown that many women grossly overestimate this risk. Careful review of the risks and benefits of both options, including the long-term complications of mastectomy, the limitations and complications of breast reconstruction, and the absence of a survival benefit from mastectomy, is critical for optimal shared decision making.

Breast cancer risk reduction - For women without a personal history of cancer who carry a known deleterious mutation in a breast cancer susceptibility gene, such as BRCA1/2, TP53, PTEN, STK11, CDH1, or PALB2, bilateral prophylactic mastectomy reduces the risk of developing cancer by more than 90 percent. Similarly, for those patients diagnosed with unilateral breast cancer and who harbor a mutation, a contralateral prophylactic mastectomy may be an option. However, the decision about whether to undergo such surgery is based on patient preference, given that with enhanced screening/surveillance, often incorporating magnetic resonance imaging (MRI), there is no demonstrable survival benefit to contralateral prophylactic mastectomy in this patient population.

Types of Mastectomy

Types of mastectomy used in modern breast surgery include

Simple mastectomy: A simple or total mastectomy also entails complete removal of the entire breast and the underlying fascia of the pectoralis major muscle. The only difference between MRM and a simple mastectomy is that the former includes a level 1 and 2 axillary dissection. With the emergence of sentinel node biopsy, simple mastectomy is performed more frequently than in the past.

Modified radical mastectomy : An MRM is a complete removal of the breast and the underlying fascia of the pectoralis major muscle, along with the level I and II axillary lymph nodes. Several randomized trials have documented equivalent survival rates with MRM compared with radical mastectomy, with less morbidity.

Skin-sparing mastectomy: The SSM is a surgical technique in which the majority of the natural breast skin envelope is preserved ; by contrast, a conventional mastectomy incision (for MRM or simple mastectomy) removes a larger portion of the overlying skin.

Preservation of the skin of the breast and the inframammary fold provides the reconstructed breast with a more natural shape and contour. The superior cosmetic result has resulted in the increasing popularity of this approach. SSM is contraindicated for inflammatory breast cancer because of cancer cell invasion of the dermal lymphatics

Nipple-areolar-sparing mastectomy: An NSM differs from other mastectomy techniques in that it preserves the dermis and epidermis of the nipple but removes the major ducts from within the nipple lumen whereas other techniques remove the NAC. If the nipple cannot be preserved, there is also an option of removing the nipple and preserving the areola (areolar-sparing mastectomy), which can also preserve the cosmetic outcome, particularly in women who do not have a sizable nipple.

Radical mastectomy:  Radical mastectomy is rarely used in modern breast surgery. A radical (Halsted) mastectomy consists of en-bloc removal of the breast, the overlying skin, the pectoralis major and minor muscles, and the entire axillary contents (level I, II, and III nodes). This extensive resection was the standard of care for treating breast cancer for many years, largely in an era where systemic therapy was unavailable.

Following mastectomy, breast reconstruction can commence at the same time ("immediate") or after the completion of cancer treatment ("delayed"). The timing of the planned reconstruction has important implications on the choice of mastectomy techniques.

Preoperative Preparation

Mark the site and side: The patient should be examined in the perioperative holding area, and the correct breast to be removed should be identified, confirmed with the patient, and marked with a permanent skin marking pen. 

Antibiotics: A preoperative antibiotic that covers skin flora should be administered before the incision is made.

Venous thromboembolism prophylaxis:  The American Society of Breast Surgeons suggests chemoprophylaxis for patients undergoing mastectomy with immediate reconstruction and/or general anesthesia for >3 hours and chemoprophylaxis for those who are at high risk of developing thromboembolic events (eg, Caprini score >5).

Early ambulation and sequential compression devices are suggested for all other patients undergoing mastectomy.

Anesthesia

Mastectomy is usually performed under general anesthesia. Pectoral nerve blocks (Pecs) types I and II are commonly performed by an anesthesiologist before the procedure or by the surgeon during the procedure. They are a part of the multimodal analgesic strategy to reduce both postoperative narcotic requirement and postmastectomy pain syndrome.

Surgical Technique

Positioning: The patient is positioned supine with their arms extended on padded arm boards at ≤90 degrees abduction from the chest wall.

Axillary staging: If the patient is having a sentinel lymph node biopsy, it should be performed before the mastectomy, which could disrupt the lymphatic flow. Sentinel lymph node biopsy or axillary lymph node dissection may be performed through the mastectomy incision or require a separate axillary incision, depending on whether adequate access to the axilla can be obtained through the mastectomy incision.

Incisions: The choice of incisions will depend upon tumor location, tumor size, and whether immediate reconstruction is planned. Given that skin-sparing mastectomy (SSM) and nipple-areolar-sparing mastectomy (NSM) are typically performed with immediate reconstruction, the incisions may be planned with the plastic surgeon. 

For a simple or modified radical mastectomy (MRM) without immediate reconstruction, the most common incision is a transverse or oblique elliptical incision including the nipple-areolar complex (NAC) with an appropriate skin paddle, with lateral extension toward the axilla. The axillary lymph nodes are accessed through the mastectomy incision. 

For an SSM, the incision may be a small ellipse around the NAC or a circular incision with or without a lateral extension.

NSM can be performed via a variety of incisions (inframammary, midlateral, circumareolar, or a combination) depending on patient anatomy and surgeon preference

Skin flaps : Skin flaps are raised superiorly to the level of the clavicle, inferiorly to the insertion of the rectus sheath, medially to the ipsilateral sternal border, and laterally to the latissimus dorsi muscle edge. Flap thickness will vary with patient body habitus and technique used (eg, tumescent) but generally is approximately 7 to 8 mm thick. The flaps are raised in the plane deep to the subcutaneous tissue and superficial to the breast parenchyma, using scissors, scalpel, or electrocautery.

Dissection from the chest wall: The breast tissue is dissected off the muscle, using cautery to decrease bleeding from the muscle.The pectoralis fascia is traditionally removed with the breast tissue in all modern mastectomies (MRM, simple, SSM, and NSM).

Tumor adherence to the muscle requires removal of that portion of the pectoris muscle with the breast specimen with a surrounding margin and placement of clips in anticipation of subsequent postmastectomy radiation therapy. 

Drains: Closed suction drains are placed through separate stab wounds inferolateral to the main incision and sewn in place. Generally, one drain is positioned beneath the inferior mastectomy skin flap, where it will best drain dependent fluid when the patient is upright. If an MRM is performed, a second drain is positioned into the axilla,

The drains are left in place until the drainage of serous fluid has decreased to approximately 25 to 30 mL per drain per day for two consecutive days.

Closure: The incisions are usually closed in two layers, using absorbable sutures. Prior to that, the flap may be fixed to the chest wall with sutures.

Complications

Complications of mastectomy include seroma, wound infection, skin flap necrosis, nipple necrosis (following nipple-areolar-sparing mastectomy [NSM]), chest wall pain, phantom breast syndrome, and arm morbidity. 

Seroma: Seroma formation, a collection of serous fluid under the skin flaps, is commonly seen after breast and axillary surgery. Untreated seroma formation results in delayed wound healing, wound infection, wound dehiscence, flap necrosis, delayed recovery, and poor cosmetic outcome. The pathophysiology of seroma formation is poorly understood, but seroma formation is increased with obesity, extensive surgery, and the use of electrocautery for skin flap dissection. 

Wound infection: The rates of postoperative wound infection after breast surgery are low because these are clean procedures. The wound infection rate after breast surgery is approximately 2 to 3 percent. Obesity, smoking, older age, and diabetes mellitus have been identified to be associated with an increased risk of infection after breast surgery.

Skin flap necrosis: The rate of skin flap necrosis from modified radical mastectomy (MRM) or simple mastectomy is estimated at 10 to 18 percent.Full-thickness skin flap necrosis requires surgical debridement and may require skin grafting and result in delays in adjuvant treatment and diminished cosmetic outcome. Prior radiation treatment, obesity, older age, and a smoking history can increase the rates of flap necrosis.

Nipple necrosis: Nipple-areolar complex (NAC) necrosis is a complication that occurs after NSM.

Factors predisposing to nipple necrosis included large breast volume, ptotic breast, smoking, prior radiotherapy, and periareolar incision. The selection criteria for NSM are partially based on avoidance of these risk factors.

Pain: Burning, aching, and tight constriction of the axilla, upper arm, and chest wall with superimposed lancinations and scar sensitivity are characteristic of postmastectomy pain.

Factors that contribute to the development of postmastectomy pain include axillary dissection and breast reconstruction with implants after mastectomy. Evaluation of chest and arm pain after mastectomy should focus upon the nature of the pain and its location and a neurologic examination to define the areas of sensory loss and hypersensitivity. Progressively worsening pain should prompt suspicion for recurrent disease. 

Phantom breast syndrome: Patients may describe a change in chest wall sensation after mastectomy sometimes described as "phantom breast syndrome". The sensation of residual breast tissue can persist for years after surgery. The most common complaint is pain, but itching, nipple sensation, erotic sensations, and premenstrual-type breast soreness are also described.

Although the cause is unknown, psychologic factors related to mastectomy have been implicated [98]. Patient education before mastectomy, outlining the possible changes in chest wall sensation and the possibility of phantom breast syndrome, may help to relieve patient anxiety if symptoms develop and may even reduce the frequency of this syndrome.

Arm morbidity:  Arm morbidity is common after mastectomy (particularly modified radical mastectomy, which includes axillary lymph node dissection) and can include arm swelling, arm pain, arm numbness, arm stiffness, shoulder stiffness, shoulder pain, or nerve injury. Postmastectomy radiation also contributes to arm morbidity and shoulder dysfunction.

After breast cancer surgery, patients should be provided with rehabilitation services as needed and informed about methods to improve shoulder function and reduce the risk of lymphedema. Exercise lowered pain intensity and reduced upper limb disability symptoms. 

Brachial plexopathy: Patients can develop brachial plexopathy from a stretch injury caused by mal-positioning in the operating room. This can be avoided by careful positioning and the use of padded arm boards.

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