Breast Cancer and BRCA 1/2 Full Gene Testing

Breast Cancer and BRCA 1/2 Full Gene Testing

Breast cancer accounts for approximately 25% of all cancers diagnosed in women. Advanced genetic tests like BRCA 1 & 2 full gene testing can help in preventing the onset of this disease. This test uses a simple blood sample to identify mutations in breast cancer susceptibility genes BRCA1 and BRCA2.

The BRCA 1/2 genes are tumour suppressor genes which repair DNA damage. They lose their function when mutations occur, which can promote cancer. Mutations in the BRCA 1/2 genes are inherited and significantly increase the risk of developing breast, ovarian, and other forms of cancer in both women and men.

A positive result implies a pathogenic mutation in one of the breast cancer genes — likelihood of developing breast or ovarian cancer is higher compared against the normal population. However, a positive result does not mean one will definitely develop cancer. By detecting these mutations early, one will have access to preventative measures and proactive treatment — leading to an overall better prognosis.

How the Test Can Reduce Cancer Risk

• Increasing surveillance — clinical breast exams, MRI and mammography every 6 months for early detection

• Taking medication such as Tamoxifen in consultation with a physician to reduce risk of developing breast cancer by about 50% in women at increased risk

• Opting for prophylactic mastectomy

• Opting for prophylactic oophorectomy

Having an accurate and detailed family history is essential to establishing a person’s risk of hereditary breast or ovarian cancer. It’s very important to undergo a genetic counselling session from a certified counsellor.

Understanding Breast Cancer / Ovarian Cancer Genetics

There is more than one gene associated with breast/ovarian cancer, so a negative result for one gene does not mean that a person is not suffering from a disease-causing mutation in another gene. If a mutation has been detected, we offer testing to family members for any identified mutation at a reduced price.

Genes involved in hereditary breast/ovarian cancer: BRCA1 (chromosome 17), BRCA2 (chromosome 13) — autosomal dominant transmission. Carrier frequency of BRCA1/2 mutations is approximately 1/500–1/1,000 in the general population.

Who Should Take This Test

• Women diagnosed with breast and/or ovarian cancer, or with first or second degree relatives with breast or ovarian cancer

• Women with a first degree relative diagnosed with bilateral breast cancer or before the age of 50

• Multiple cases of breast or ovarian cancer on the same side of the family, especially in more than one generation

• A family member with breast cancer diagnosed before the age of 35

• A family member with both breast and ovarian cancers

• Men with a strong family history of breast/ovarian cancer

Written by Arun Kiran P, Genetic Counsellor, MapmyGenome.