Breast cancer is the most common cancer to affect women. It occurs most often in women over 50 years of age, but sometimes can also affect men, as men also have breast tissue that never fully develops. Breast cancer usually grows in the cells that produce milk and which line the milk ducts. These abnormal cells grow uncontrollably, and can spread beyond their natural boundaries. The cells can potentially spread to other sites within the body, such as the brain or liver.
Breast cancer is often diagnosed after finding a lump in the breast, although it can also be found by a screening test called a mammogram. Surgical intervention usually forms part of the treatment of breast cancer and it may be supplemented with radiotherapy, chemotherapy or hormonal treatments. Treatment of breast cancer has improved markedly over the past few decades, so most people will beat the disease.
A medication-based treatment, usually used in the treatment of cancers. There are numerous, different types of chemotherapy drugs that can be prescribed by a specialist. These can commonly be used alongside other cancer treatments such as surgery and radiotherapy.
A treatment that uses ionising radiation to kill or control growth of malignant cancer cells.
Relating to hormones, which are chemicals secreted in one part of an organism and transported to another part of that organism, where they have a specific effect.
An image of breast tissue produced by an X-ray as the breast is pressed between two plates. It is typically used to screen for breast cancer.
The cause of breast cancer, as with other cancers, is damage to cellular DNA. This damage results in uncontrolled growth of these abnormal cells, which leads to formation of a tumour. Tumours can invade nearby tissue, or cancerous cells can separate from the tumour and spread throughout the body via the bloodstream or lymphatic system. The exact causes of this cellular damage in the breast are not known, but there are a number of proposed risk factors.
The genetic material of all living cells and some viruses. The full name is deoxyribonucleic acid.
A network of vessels, lymph nodes, the spleen and other organs that transport lymph fluid between tissues and bloodstream.
Risk factors for breast cancer include:
Inherited by an offspring from their parent/s.
The use of either synthetic or natural hormones from external sources by women going through menopause.
A female sex hormone produced by the ovaries and the placenta during pregnancy. It also plays an important role in the menstrual cycle.
A treatment that uses ionising radiation to kill or control growth of malignant cancer cells.
The stage in a woman's life where she no longer experiences menstruation. This is usually defined as occurring 12 months after her last period/menses.
The type of breast cancer is determined by the type of cell it starts in.
Most breast cancers are ductal carcinomas, which begin in the lining of the milk ducts in breast tissue. Ductal carcinomas can be further classified as follows:
This breast cancer originates in the lobules of the breasts, which are the glands that produce milk. Types of lobular carcinoma include:
Anatomy of the breast.
The fundamental unit of life; the simplest living unit that can exist, grow, and reproduce independently. The human body is composed of trillions of cells of many kinds.
Treatment outcomes can vary greatly, depending on the stage of cancer. Cancer is staged according to the size and location of the primary tumour and whether it has spread to lymph nodes or organs throughout the body.
| Stage I | The tumour is 2 cm or less in diameter and small clusters may have spread to local lymph nodes. |
| Stage II | |
| Stage IIA | Either a tumour that is 2 cm or less and has spread to 1-3 lymph nodes near the breast, or is 2-5 cm and has not spread to the lymph nodes. |
| Stage IIB | The tumour is 2-5 cm and the cancer has spread to the lymph nodes, or is greater than 5 cm and has not spread to the lymph nodes. |
| Stage III | |
| Stage IIIA | A tumour of any size that has spread to 4-9 lymph nodes in the armpit or the breastbone, or a tumour larger than 5 cm, along with small clusters of cancer cells in lymph nodes, or a tumour greater than 5 cm that has spread to 1-3 local lymph nodes. |
| Stage IIIB | The tumour can be any size and has spread to the skin and/or the wall of the chest. It may also have spread to 9 or more lymph nodes in the armpit, or lymph nodes around the breastbone. |
| Stage IIIC | A tumour of any size that has spread to 10 or more lymph nodes in the armpit, or to lymph nodes around the breastbone or collarbone. |
| Stage IV | The cancer has spread to other body organs such as the lungs, bone, and brain. |
The following signs and symptoms of breast cancer may or may not be apparent:
Being aware of any changes in your breasts, such as lumps or changes in size or shape, can often be the first sign something is wrong and prompt you to see a doctor. A doctor or nurse will then perform a breast examination for lumps or changes in the breast and armpits.
There is no longer a recommendation for women to have routine examinations performed by a health professional.
Most commonly, a mammogram and/or an ultrasound are used to detect breast cancer. If a suspicious mass is detected with scanning, it will be biopsied for a definitive diagnosis. If a cancer is confirmed, then other forms of imaging may be used to further detail the mass, or to help determine if the tumour has spread to lymph nodes, organs or bones.
A range of different scans are used for diagnosing and monitoring breast cancer:
A sample of breast tissue (biopsy) is removed using a needle, followed by microscopic examination by a pathologist. This can confirm and characterise the cancer, which can help in selecting treatment options.
A scan that uses high-frequency soundwaves to produce images of the body’s internal structures.
An image of breast tissue produced by an X-ray as the breast is pressed between two plates. It is typically used to screen for breast cancer.
A lumpectomy involves surgical removal of the cancerous tissue and some of the surrounding tissue. It is the least invasive of the surgical interventions for breast cancer and generally causes little or no change to the appearance of the breast.
This involves the partial removal of some of the breast tissue, the amount of which varies according to the size and shape of the tumour. It may involve a quarter of the breast or a segment.
This surgery is the complete removal of the breast. However, there are a number of ways that this can be defined:
Chemotherapy works by attacking cancer cells and stopping their reproduction. Various medications are used, which can be administered intravenously or orally.
There are three general types of chemotherapy:
Side effects occur because chemotherapy can also affect healthy cells. Your doctor will monitor your dosage carefully to ensure the optimal therapeutic dosage is achieved.
Chemotherapy can slow down the development of breast cancer.
In this type of therapy, focused X-rays are applied to the area where the tumour is located. Another form of radiation therapy is brachytherapy. This involves inserting a small, radioactive implant in the tumour or the nearby area, which deliver cell-destroying radiation directly into the tumour. Radiotherapy can be used alone, or in addition to surgery and/or chemotherapy.
If the tumour contains receptors for oestrogen or progesterone hormones, hormone therapy is often used to block the action or lower the production of these hormones that are otherwise involved in supporting the growth of cancerous cells. Aromatase inhibitors can be used to block oestrogen production and tamoxifen and fulvestrant (not yet available in Australia) can be used to block oestrogen receptors on cancer cells. This is not the same as hormone replacement therapy given to menopausal women.
Some people diagnosed with breast cancer seek out complementary and alternative therapies. None of these alternative therapies are proven to cure cancer, but some can help people feel better when used together with conventional medical treatment. It is important to discuss any treatments with your doctor before starting them, since some complementary treatments can cause harm or interfere when combined with conventional cancer treatment.
The fundamental unit of life; the simplest living unit that can exist, grow, and reproduce independently. The human body is composed of trillions of cells of many kinds.
A medication-based treatment, usually used in the treatment of cancers. There are numerous, different types of chemotherapy drugs that can be prescribed by a specialist. These can commonly be used alongside other cancer treatments such as surgery and radiotherapy.
The use of either synthetic or natural hormones from external sources by women going through menopause.
A female sex hormone produced by the ovaries and the placenta during pregnancy. It also plays an important role in the menstrual cycle.
A treatment that uses ionising radiation to kill or control growth of malignant cancer cells.
There is a wide range of possible side effects from breast cancer treatments, including:
Inflammatory breast cancer can result in the swelling of the breast (oedema).
This is when the cancer spreads to other parts of the body through the bloodstream and lymphatic system. Generally, once breast cancer has spread to distant sites, it is not curable. However, treatments can be used to slow down the disease.
Not leading to cancerous growth. Not harmful.
A medication-based treatment, usually used in the treatment of cancers. There are numerous, different types of chemotherapy drugs that can be prescribed by a specialist. These can commonly be used alongside other cancer treatments such as surgery and radiotherapy.
A connecting surface or tissue between two bones.
A network of vessels, lymph nodes, the spleen and other organs that transport lymph fluid between tissues and bloodstream.
A respiratory disease in which scar tissue forms in the lung tissues, sometimes as a result of other lung diseases.
A treatment that uses ionising radiation to kill or control growth of malignant cancer cells.
In 2010, the five-year survival rate for Australians with breast cancer was 89%. In general, the smaller the tumour, the higher the survival rate. For women who survive the first year, the survival rate increases to 90% and for women who survive the first five years, the forward five-year survival rate further increases to 93%. [1]
Five-year survival rates are calculated on people who were treated in the preceding five years. Advances in treatment since then might result in better outcomes for people with breast cancer today.
Cancer survival and prevalence in Australia: period estimates from 1982 to 2010. Australian Government – Australian Institute of Health and Welfare. Accessed 22 September 2014 from
Being aware of changes in your breasts is important for the early detection of breast cancer. It would be good to talk to your doctor about any changes in the size and shape of your breasts, or the formation of lumps. Getting regular mammograms once you reach 50 years of age, maintaining a healthy weight, quitting smoking and reducing alcohol intake are the best means of preventing breast cancer. If you have a family history of breast cancer, you can talk to your doctor or genetic counsellor regarding your specific situation.