Understanding the different types of breast cancer treatments
The main treatments for breast cancer are surgery, chemotherapy, radiotherapy, hormone therapy and biological therapy. The best treatment option depends on the size of the tumour and how advanced the cancer is.
Surgery is a local treatment for breast cancer, meaning it only treats the part of the body operated on. It may cure the cancer if it is completely contained in the breast. The two main types of breast cancer surgery are breast-conserving surgery (surgery to remove the tumour), and a mastectomy (surgery to remove the entire breast). In most cases, the earlier a cancer is detected, the easier it is to remove it. Surgery may not be the best option is the cancer has spread, or is at an advanced stage. According to the NHS, studies have shown that breast-conserving surgery followed by radiotherapy is as successful as a mastectomy at treating early-stage breast cancer.
Chemotherapy is treatment with cell killing (cytotoxic) drugs, of which over 100 are currently available, and new ones are being developed all the time. Chemotherapy may be received by an injection into the bloodstream, a drip into the bloodstream through a vein, or via tablets or capsules. Chemotherapy may be given to breast cancer patients after surgery to reduce the risk of the cancer coming back. If breast cancer has spread beyond the breast and lymph nodes to other parts of the body, chemotherapy won't cure the cancer. However, it may shrink the tumour, relieve the symptoms and help lengthen lifespan.
Radiotherapy uses radiation, typically X-rays, to treat cancer, by destroying the cancer cells in the breast by damaging the cells’ DNA. The aim is to give a high dose of radiation to the cancer cells and as low a dose as possible to the surrounding healthy cells, which can then recover because they are better at repairing themselves than the cancer cells. Radiotherapy is usually given to breast cancer patients after surgery and chemotherapy, and four types are available:
- Breast radiotherapy — after breast-conserving surgery, radiation is applied to the remaining breast tissue
- Chest wall radiotherapy — after a mastectomy, radiotherapy is applied to the chest wall
- Breast boost — some women may be offered a boost of high-dose radiotherapy in the area where the cancer was removed; however this can affect the appearance of the breast (particularly if they are large), and result in other side effects, including hardening of the breast tissue (fibrosis)
- Radiotherapy to the lymph nodes — radiotherapy is aimed at the armpit (axilla) and the surrounding area to kill any cancer present in the lymph nodes
Hormone therapy may be used to treat cancers that are hormone sensitive or hormone dependent, which may include breast cancer. Hormone therapies may slow down or halt the growth of cancer by stopping hormones being made, or preventing hormones from making the cancer cells grow and divide. For breast cancer patients who are deemed suitable this type of treatment, the different types of hormone therapies include tamoxifen, aromatase inhibitors and luteinising hormone (LH) blockers. Tamoxifen, one of the most common hormone therapies for breast cancer, works by stopping the hormone oestrogen from reaching the cancer cells.
A new study published in the New England Journal of Medicine provided strong evidence that for some women with early stage breast cancer hormone therapy may be more effective than chemotherapy.
Using a gene-based test called Oncotype Dx, doctors can determine how potentially aggressive a tumour may be. A recurrence score between 0 and 100 is produced after 21 genes in the tumour are scanned, and generally speaking the lower the score, the more likely it is that drug therapy will be enough to treat the cancer.
Previous Oncotype Dx studies used archived tumour samples, but the NEJM trial — the Trail Assigning Individualized Options for Treatment (TAILORx) — included 10,253 women diagnosed with breast cancer. They all had tumours with hormone receptors, meaning they would respond to hormone therapy, and the cancer hadn’t spread to the lymph nodes.
The women with an Oncotype Dx recurrence score of less than 11 — around 16 percent of the women in the study — were assigned hormone therapy only, without chemotherapy. And the results were impressive: 99 percent of them survived to five years, and had a less than 2 percent risk of recurrence.
Dr. Joseph Sporano, lead author of the study, told TIME: “What we’ve shown is that if you have a low recurrence score, you do really, really well with [hormone] therapy alone. The likelihood of responding to chemotherapy would be nill. So I think we can be much more confident in making the recommendation to just use [hormone] therapy alone especially in patients where we might have been a little skittish about recommending sparing chemotherapy.”
Biological therapy (targeted therapy)
Biological therapy works by blocking the effects of a protein that stimulates the growth of breast cancers. This protein is called human epidermal growth factor receptor 2 (HER2), and a patient with high levels of HER2 who is deemed suitable to have biological therapy may be prescribed a medicine called trastuzumab, a monoclonal antibody. Received intravenously through a drip, it targets and destroys HER2-positive cancer cells. Typically, early breast cancer requires a session of trastuzumab (in hospital) once every three weeks, while more advanced cancer requires weekly sessions.
For more information about breast cancer treatments visit Cancer Research UK.