Breast cancer is one of the most dreadful conditions to affect many women globally. It is a silent killer that 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 this significantly increases the risk of developing breast, ovarian, and other forms of cancer in both women and men. Women who have inherited these faulty genes have higher risk of developing breast and ovarian cancer compared with the general population.
BRCA test is offered to people with personal or family history, or those who have specific types of cancers in their family and these people are more likely to inherit these mutations. A positive result implies a pathogenic mutation in one of the breast cancer genes; likelihood of developing breast cancer or ovarian cancer is higher when compared against the normal population. However, the positive result does not really mean that one will develop cancer.
By detecting these mutations early, one will have access to preventative measures and proactive treatment – leading to an overall better prognosis.
This genetic test can play a major role in reducing the risk towards cancer in various ways:
- Increasing surveillance- clinical breast exams, MRI and Mammography tests every 6 months in order to help early detection.
- Taking a medication such as Tamoxifen in consultation with a physician to reduce risk of developing breast cancer by about 50% in women who are at increased risk of the disease.
- Opting for a prophylactic mastectomy.
- Opting for a 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 counseling session from a certified counsellor which can be scheduled at Mapmygenome.
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 your patient undergoes full gene sequencing of BRCA1/2 and a mutation has been detected, we offer testing to family members for any identified mutation at a reduced price (testing of known familial mutation).
Genes involved in hereditary breast/ovarian cancer:
- BRCA1 – chromosome 17.
- BRCA2 – chromosome 13.
- Autosomal dominant transmission.
- Carrier frequency of BRCA1/2 mutations.
- ~1/500 – 1/1,000 in general (Caucasian) population.
Who should take this test
The hereditary form of breast/ovarian cancer accounts for 5-10% of all the cases and is clearly associated with mutations in the BRCA 1/2 genes.
Patients who should be considered for genetic testing due to a suspected hereditary mutation.
- Women diagnosed with breast and/or ovarian cancer and women with first or second degree relative(s) with breast or ovarian cancer or
- 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 when breast cancer is diagnosed before the age of 50.
- 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.
- More risk criteria can be found in national and international guidelines, such as the NCCN clinical practice guidelines for breast cancer. Having an accurate and detailed family history is essential to establishing a person’s risk of hereditary breast or ovarian cancer.
- When family history and/or clinical presentation indicates a risk of hereditary breast/ovarian cancer.
By detecting cancer early, one will have access to preventative measures and proactive treatment – leading to an overall better prognosis.
About the Author
Arun Kiran P, Genetic Counselor at Mapmygenome- Wellness is in our DNA
