Mastectomy, pioneered by William Halsted in the latter part of the 19th century, remained the most common method of breast cancer treatment until the 1970s. The history of mastectomy is initially of large resections, followed by reductions in the resected parts until the modern mastectomy techniques were developed.
At the closing of the 19th century, the common belief regarding cancer spread was that it permeated through lymphatic channels to regional nodal sites. This was thought to require an en-bloc resection of the tumour, lymphatic channels and lymph nodes to achieve cure. The most well known proponent of mastectomy was Halsted, who published a case series of radical mastectomies in 1894. You can still read the initial journal article on PubMed Central, together with the surgical technique, here. This procedure involved resection of the breast with overlying skin, the pectoralis major and minor muscles, and all axillary lymph nodes (levels I-II-III). Although this approach provided good local control rates, it was very extensive and has not remained in routine use. Halsted's original case series served as the basis for introduction of radical mastectomy as the principal procedure for breast cancer, with local control rates of over 90%.
Extended and Supra-Radical Mastectomy
Extended radical mastectomy expanded upon radical mastectomy, and developed in attempt to remove metastases to the internal thoracic nodes. It was developed by Handley and others in the mid-20th century. More extensive operations were also devised; including thoracotomy to explore mediastinal nodes and amputation of the upper limb (forequarter amputation). These 'supra-radical mastectomies' were associated with no improvement in overall survival, and also with high perioperative mortality (up to 15%). This, together with the understanding that women with supraclavicular lymphadenopathy had very advanced disease that was incurable surgically, led to the abandonment of these procedures by the early 1960s.
Modified Radical Mastectomy
Contemporaries of WS Halsted criticised his extensive surgical technique, favouring less mutilating surgery. The landmark article was published in 1948 by Patey and Dyson, again available at PubMed Central. Using the knowledge of lymphatic drainage published by Gray in the 1930s, they modified their technique to spare the pectoralis major muscle while removing the pectoralis minor muscle to allow access to the axillary nodes. This procedure had similar survival rates to radical mastectomy and became adopted throughout Europe in the 1960s; radical mastectomy remained the preferred procedure in the USA until the 1970s.
Total Mastectomy / Simple Mastectomy
A further reduction in surgical excision, the total mastectomy removes the breast tissue and overlying skin without intruding into the axilla or pectoral muscles. This procedure has become more commonly used since the advent of sentinel node biopsy. It is the most commonly performed mastectomy operation in the modern world.
Breast Conserving Surgery
Although thought to be insufficient for the treatment of cancer during the majority of the 20th century, local treatments for breast cancer without mastectomy are now the most commonly used method for treatment. This has relied upon the development of several technologies:
- Better imaging modalities (mammogram, ultrasound) that allow accurate determination of the size of the tumour
- Better adjuvant therapies (particularly radiotherapy) that allow eradication of microscopic residual disease within the breast
- Sentinel node biopsy (allowing for staging of the axilla without extensive surgery)
- Screening programs which allow for earlier detection of breast cancer
- Adoption of uniform staging procedures for breast cancer (TNM system)
The combination of these technologies allows surgeons to determine the best treatment option for a particular patient, whether that be breast-conserving therapy or mastectomy. The advantages of breast conserving therapy are:
- Less invasive surgery with less perioperative risk
- Similar outcomes to mastectomy for small (T1-T2) breast tumours
- Better cosmetic outcomes
However, wide local excision must be coupled with adjuvant radiotherapy. Some patients are unable to have a wide local excision for technical reasons. Some patients prefer mastectomy.
- Contraindications include inability to receive radiotherapy (radiosensitivity, prior radiotherapy), extensive involvement of breast tissue, or inability to achieve clear margins.
- Relative contraindications include systemic fibrotic diseases, large tumours over 5 cm, or women with BRCA1/2
- In pregnant patients, breast conservation can be appropriate when diagnosed in the 3rd trimester. The patient can undergo a wide local excision during the latter part of pregnancy, deferring radiotherapy until after birth. If the patient is to receive chemotherapy, even pregnancies only in the 2nd trimester could be considered although this is not commonly done.
Some special situations regarding breast conservation exist:
- Malignancy lying beneath the nipple-alveolar complex often results in poor cosmesis with wide local excision. These women may prefer to undergo mastectomy with reconstructive surgery at a later date.
Axillary dissection is less common with the advent of sentinel node biopsy.
Sentinel Node Biopsy
If sentinel nodes are positive, or there is clinical stage N1 disease, the axillary level I and II nodes are removed en bloc. Ideally there should be greater than 10 nodes present; this is a large criticism of two large post-mastectomy radiotherapy trials where a mean number of 7 nodes was removed.
There is significant debate as to whether resection of axillary nodes is required when a positive sentinel node is identified on histopathology. One trial has shown that proceeding with axillary dissection for an otherwise favourable prognosis patient (clinically N0, T1-2, < 3 sentinel nodes on histopathological examination) simply causes more morbidity with no increase in survival, so long as the patient is receiving adjuvant radiotherapy.
2: Invasive Breast Cancer
- Outcomes and Follow-Up
- Special Scenarios