Testing for the Breast Cancer Gene
Breast cancer is one of the most common cancers worldwide, so statistically it is not shocking that women in the same family may develop the disease at some time in their lives. However, when multiple cases of the disease are diagnosed among close relatives in the same (blood) family, then it may be that there is a familial, genetic link among the cases. Today there are four main genes known to be related to breast cancer including BRCA1, BRCA2, TP53 and PTEN. There are tests for these genes to help women determine if they carry them and thus may be at higher risk of developing breast cancer.
BRCA1 and BRCA2 GenesBRCA1 and BRCA2 are the most widely recognised genes related to breast cancer. These identification codes stand for "Breast Cancer 1" and "Breast Cancer 2" and indicate that there are alterations to the genes that are indicative of hereditary breast cancer. However, not every individual who carries these genes will develop breast cancer as the highest risks are associated when the carriers also have multiple cases of breast cancer in their close family, have cases of both breast and ovarian cancer in the family, have family members who have had two primary cancers, or are of Eastern European/Ashkenazi Jewish background.
TP53 GenesTP53 is a gene known to be associated with the suppression of tumours by instructing the synthesis of a tumour protein known as tumour protein 53 that regulates cell division. When this protein does not work correctly cell division can speed up and get out of control, such as in cancerous cell multiplication. Thus an alteration to the TP53 gene could allow cancers such as breast cancer to develop. In medical research it has been determined that alterations of the TP53 gene can be indicative of the development of breast cancer.
PTEN GenesPTEN stands for "phosphatase and tensin homolog" gene. This is another tumour suppression gene that, when altered or mutated is known to contribute to cancer development. In medical research, mutation in the PTEN gene have been documented in breast cancer cases.
Testing for Breast Cancer GenesIt must be remembered that testing for breast cancer genes is not the same as testing for breast cancer. If one of these genes is discovered it does not necessarily mean that breast cancer will develop. Only women who have a strong family history, as stipulated by the National Institute for Health and Clinical Excellence (NICE) guidelines on familial breast cancer, will be tested for these genes in the UK.
These tests are based on blood, so blood samples are required, and they are easier to carry out if a relative who has had breast cancer donates a sample as well. Women who do not qualify for these tests under the NICE guidelines may investigate private testing options. However, any woman who decides to be tested should think about how they would react to a positive result. Would they simply continue with regular breast screening? Would they opt for a pre-emptive removal of the breast? Would they attempt to join a trial prevention group? In order to make the most informed decision, women should discuss test results with medical professionals. For women who have the tests carried out privately, this may be difficult but starting with a GP is a good way to determine if any other discussions are necessary.