Below is a brief explanation of the following breast cancer types.
Remember this information is introductory and you are urged to seek more detailed information from your doctor or specialist.
Early breast cancer
Early breast cancer is contained within the breast and may or may not have spread to the lymph nodes in the breast or armpit. At this stage, some cells may have spread further than the breast or armpit area, however, these cannot be detected.
Early breast cancer can be successfully treated and is not fatal for the majority of women who receive treatment.
Locally advanced breast cancer
This is a breast cancer which is larger than 5cm and may have spread into the lymph nodes or other tissues in the vicinity of the breast.
Diagnosis of locally advanced breast cancer requires the same tests as advanced breast cancer. It’s also advisable to have regular follow-up treatment so that, should the cancer return, it can be detected and treated as early as possible.
Metastatic breast cancer
Metastatic breast cancer results when cancer cells travel through the lymph system or through the blood to reach other parts of the body. Although tumours develop in places well away from the breast, like the liver, lungs, brain, lymph nodes or bones- it is not a new cancer. These secondary tumours are referred to as metastases. This is a spreading of the original breast cancer.
Invasive or non-invasive (in situ ) breast cancer
Breast cancers are either invasive or non invasive (in situ). This distinction is the single most important fact about any breast cancer.
Non-invasive or in situ (which means in the same place) cancers are confined to the milk-making glands and do not spread to other parts of the breast or body.
Invasive cancers are more serious. They have begun to break through the normal breast tissue barriers and invade surrounding areas. They can then spread cancer to other parts of the body through the bloodstream and lymphatic system.
Node positive or node negative breast cancer
Node positive means there is cancer in the lymph nodes. Conversely, node negative means there is no cancer in the lymph nodes. Cancer found in the lymph nodes is classed into three categories.
- Minimal or microscopic: where only a small number of cancer cells can be found
- Significant or macroscopic: where a particular lymph node or group of nodes is affected. These can often be seen with the eye or felt by hand.
- Extra-capsular extension: Where the cancer invades beyond the lymph node wall and into the surrounding tissue.
Hormone receptors in breast cancer
A hormone receptor is a protein on the surface or inside a cell. It receives signals from a particular hormone and “switches on” growth in the cell.
A breast cancer is ER-positive if it has receptors for the hormone oestrogen. If it has receptors for the hormone progesterone it is called PR-positive. Conversely, cells that do not have receptors for these hormones are called ER-negative or PR-negative.
Gene alterations in breast cancer
Inherited alterations
Example: BRCA1 and BRCA2
BRCA1 and BRCA2 are genes. Their names are short for Breast Cancer 1 and Breast Cancer 2.
Alterations or mutations in these genes can be inherited and can make women more susceptible to developing breast and other forms of cancer.
BRCA1 and BRCA2 genes are involved in many cases of hereditary breast and ovarian cancer. However, not every woman from a family with a history of BRCA1 or BRCA2 mutations carries these altered genes.
Gene overexpression
Normal cells secrete proteins and receptors at a particular rate. An increase or amplification in this rate is called oncogene overexpression. This occurs when an oncogene (or gene) “overexpresses” itself by making excessive amounts of normal or abnormal proteins and receptors. This may lead to cancer.
Example: HER2
HER2 is a gene that helps control how cells grow, divide, and repair themselves. It is crucial in the control of abnormal or defective cells that could become cancerous.
HER2 overexpression occurs when the HER2 gene “overexpresses” itself by making excessive amounts of normal or abnormal proteins and receptors. HER2-positive breast cancers are those which have an oversupply of HER2 genes and tend to grow and spread more rapidly than other breast cancers and therefore HER2 status has important implications for the prognosis and treatment of breast cancer. 20-25% of women with breast cancer have HER2-positive disease.
