Treatments for Breast Cancer
A wide array of potential management options are available for breast cancer.
All patients diagnosed with breast cancer should be discussed within the multidisciplinary team (MDT) meeting, which includes breast surgeons, radiologists, oncologists, pathologists, and breast cancer specialist nurses, to provide the most suitable and patient-focused management plan available.
Breast conserving treatment is only suitable for individuals with localised operable disease and no evidence of metastatic disease.
A Wide Local Excision (WLE) is the most common breast conserving treatment and involves excision of the tumour, typically ensuring a 1cm margin of macroscopically normal tissue is taken along with the malignancy.
This option is typically only suitable for focal smaller cancers and will also be dependent on the location and relative size of the breast.
A mastectomy removes all the tissue of the affected breast, along with a significant portion of the overlying skin (the muscles of the chest wall left intact). The amount of skin that is excised is often dependent on whether a reconstruction is planned.
Mastectomies are indicated in cases of multifocal disease, high tumour:breast tissue ratio, disease recurrence, or patient choice (or in risk-reducing cases, as discussed below)
Axillary surgery is most commonly performed alongside WLE and mastectomies, in order to assess nodal status and remove any nodal disease
A sentinel node biopsy involves removing first lymph nodes into which the tumour drains. The nodes are identified by injecting a blue dye with associated radioisotope into the peri-areolar skin; radioactivity detection and / or visual assessment (as the nodes become blue) can then identify the sentinel nodes, which can be removed and sent for histological analysis.
Axillary node clearance involves removing all nodes in the axilla, ensuring to not damage any associated important structures within the axilla, which are then sent for histological analysis. Common complications from this operation include paraesthesia, seroma formation, and lymphedema in the upper limb.
A risk-reducing mastectomy is an operation to remove healthy breast tissue in order to reduce the risk of developing breast cancer.
Risk-reducing mastectomy is only suitable for patients with a high risk of developing breast cancer and requires appropriate counseling to reach this difficult decision. In cases of suspected genetic risks, then patients are often referred to a genetic counsellor.
Factors conferring risk include:
- A strong family history of breast or ovarian cancer
- Testing positive for genetic mutations, such as BRCA1 or BRCA2, PTEN, or TP53 mutations
- Previous history of breast cancer
In malignant non-metastatic disease, therapy for breast cancer is adjuvant so as to reduce the risk of relapse.
Medical treatment is commenced usually after primary surgery, yet it can often be the treatment of choice in elderly patients or in those unfit for surgery.
Although there are several treatment options available, such as chemotherapy, radiotherapy*, and immunotherapy, hormone manipulation is the biggest contributor to improved survival.
*Adjuvant radiotherapy is offered to all patients after WLE and in post-mastectomy cases with positive resection margins, tumour size >5cm, or 4 or more pathological nodes in axilla.
Tamoxifen is used typically in pre-menopausal patients. It acts through blockade of oestrogen receptors, therefore also has a role in prophylaxis against breast cancer.
It is known to increase the risk of thromboembolism during and after surgery or periods of immobility, as well as increasing the risk of uterine carcinoma (due to its pro-oestrogenic effect on the uterus)
Aromatase inhibitors, such as Anastrozole, Letrozole, or Exemestane, act through binding to oestrogen receptors to inhibit further malignant growth and preventing further oestrogen production, as well as blocking the conversion of androgens to oestrogen in peripheral tissues.
Aromatase inhibitors are advised for post-menopausal patients as adjuvant therapy, shown to be superior in this patient subgroup to Tamoxifen, however are more expensive.
Immunotherapy may be used in patients whose cancers express specific growth factor receptors.
One of the most common targets is the human epidermal growth factor receptor (HER-2 positive malignancies) for which Herceptin (Trastuzumab) is a monoclonal antibody that targets its activity.
It can be used either as adjuvant therapy or as a monotherapy in patients who have received at least two chemotherapy regimens for metastatic breast cancer*.
*A common side-effect of treatment is cardiotoxicity, hence cardiac function must be monitored before and during treatment
In recent years, oncoplastic surgery has emerged as a new approach for either extending techniques to allow breast-conserving surgery or to reconstruct the breast following mastectomy.
There are several surgical reconstructive techniques in the oncoplastic treatment of breast malignancy, broadly divided into mammoplasty and flap formation
A therapeutic mammoplasty involves a WLE combined with a breast reduction technique.
The end-result is a smaller and uplifted breast, with the nipple and areola preserved along with their blood supply and the nipple relocated to suit the new breast.
A Latissimus Dorsi flap involves a portion of the Latissimus Dorsi muscle and its overlying skin used to reconstruct the removed breast, either as a free or pedicle flap. Only a certain amount of muscle can be used and so this technique is only useful for reconstructing smaller breasts.
A Transverse Rectus Abdominal Muscle (TRAM) flap involves the abdominal muscle, skin, and fat to reconstruct the removed breast, also either as a free or pedicle flap. This has the benefit of removing abdominal fat but the disadvantage of reducing abdominal muscle strength.
A Deep Inferior Epigastric Perforator (DIEP) flap uses tissue from the abdomen and its overlying skin to reconstruct the breast, yet is only ever performed as a free flap. The advantage of the DIEP flap is that, unlike the TRAM flap, no muscle is used therefore abdominal muscle strength is usually maintained.
- A wide array of medical and surgical options are available for treatment of breast cancer
- Decisions for wide local excision versus mastectomy will be made depending on a number of factors, including tumour size, location, and size of breast
- Hormone treatments provide the biggest contributor in medical management to improved survival in breast cancer
- Improvements in oncoplastic techniques have allowed for improved breast conservation surgery and reconstruction following mastectomy.