BRCA1/2 comprehensive analysis: Role in breast and ovarian cancer
BRCA1 and BRCA2 genes
It is essential for you to know about BRCA1/2 genes to understand their function in cancer. BRCA1 and BRCA2 or breast cancer genes are human genes which form tumor suppressor proteins. The role of these proteins is to assist repair your damaged DNA and assure the stability of the cell’s genetic material. Your DNA damage may not be repaired correctly if either of these genes gets mutated or changed, as a result, defective protein products are formed which lead to additional genetic modifications that can cause cancer.
The risk of female breast and ovarian cancer is increased in case of specific inherited mutation of BRCA1 and BRCA2 genes, leading to what is called the hereditary breast ovary syndrome.
Who is at risk of cancer?
Your doctor will order testing or comprehensive analysis for BRCA1 and BRCA2 genes if you have a family history of breast, ovarian, fallopian tubes or peritoneal cavity cancer. Factors which will increase the risk for getting mutation in the BRCA1/2 genes include:
Women with early onset (age<40) breast cancer
- Cancer in both breasts in the same woman
- Both breast and ovarian cancers in either the same woman or the same family
- Multiple breast cancers
- Two or more primary types of BRCA1 or BRCA2 related cancers in a single-family member
- Cases of male breast cancer
- Ashkenazi Jewish ethnicity
What is your risk to develop cancer?
While not everyone who has BRCA1/2 mutation will develop cancer, its good to know the risk of development of cancer.
About 55 to 65 percent of women who inherit a harmful BRCA1 mutation and around 45 percent of women who inherit a harmful BRCA2 mutation will develop breast cancer by age 70 years as per the latest estimates. On the other hand, 39 percent of women who inherit a harmful BRCA1 mutation and 11 to 17 percent of women who inherit a harmful BRCA2 mutation will develop ovarian cancer by age 70 years.
Interpretation of BRCA1/2 comprehensive analysis
BRCA1/2 comprehensive analysis can give several possible results: a positive result, a negative result or an ambiguous or uncertain result.
Positive result – In case you have a positive test result, it indicates that you have inherited a known harmful mutation in BRCA1 or BRCA2 and hence your risk of developing cancer is increased. No information regarding whether or when you will actually develop cancer is given as not all people with mutation develop this cancer. In addition, this test can disclose essential health information about your relatives, in contrast to other medical tests. You potentially can pass the mutation to your sons and daughters, whether or not you develop the cancer yourself. There is 50 percent chance that each child will inherit a parent’s mutation. Also, there is 50 percent chance that your siblings will inherit the mutation.
Negative result – Negative test result can be more difficult to understand than a positive result since your family history of cancer and whether a BRCA1 or BRCA2 mutation has been identified in a close relative determine negative result. A negative test result is called as true negative when your close relative is known to carry a harmful BRCA1 or BRCA2 mutation. However, your negative test means that you do not carry the harmful mutation responsible for the familial cancer, and thus cannot pass it on to your children. Your risk of cancer is similar as someone in the general population.
On the other hand, a negative result is false negative if comprehensive analysis recognizes no mutation, while you have a family history that suggests the possibility of having a harmful mutation in BRCA1 or BRCA2. While the possibility of missing a known harmful BRCA1 or BRCA2 mutation is very low, it can take place and further new unidentified mutations in BRCA1 and BRCA2 genes can occur which lead to a false negative result.
Ambiguous or uncertain result – You get ambiguous or result of uncertain significance when a change in BRCA1 and BRCA2 genes has not been earlier associated with cancer. This is not known whether this specific gene change affects a person’s risk of developing cancer. Additional studies of variants of uncertain significance will be required for a specific mutation being re-classified as either harmful or clearly not harmful.
Advantage of BRCA1/2 comprehensive analysis
Positive test result helps you to make informed decision about your future and lays myriad of options available for further treatment. Negative result which is true gives you peace of mind and assurance that there is no familial risk as well as no risk of passing harmful mutations to the future generations.
Your doctor will refer you for genetic counselling with an expert counselor in cancer genetics before and after BRCA1/2 comprehensive analysis who will assist you in getting a better insight of your condition and management. Further management will be based on your analysis results. In case of positive result, you will be recommended to have enhanced screening, prophylactic risk reducing surgery and chemoprevention.
Thus, BRCA1/2 comprehensive analysis has, in fact, a vital role in diagnosis and management of breast and ovarian cancer.