What are BRCA 1 and BRCA 2?
BRCA 1 and BRCA 2 are genes seen in all women and men, which produce proteins that help repair DNA and maintain cellular integrity during cellular reproduction. Good cell health, maintained in part by BRCA 1 and BRCA 2 genes, helps prevent cancer from occurring and suppresses tumor growth when cancerous cells do appear.
When these genes are mutated, it can interfere with the body’s ability to produce these cancer-fighting proteins, which greatly increases the person’s risk of developing various types of cancers, especially breast and ovarian cancer. These mutations can be passed down by the mother or the father, and can affect cancer rates in both men and women, although they tend to cause more damage in women.
Should I get tested for BRCA 1 and BRCA 2 gene mutations?
The decision to get tested for BRCA 1 and BRCA 2 gene mutations is personal, and depends on the person’s risk for developing breast or ovarian cancers, based on their family history. In general, if a woman does not have a family history of breast or ovarian cancer and has not developed breast cancer or ovarian herself, genetic testing is considered unnecessary. However, people who have seen breast or ovarian cancers in immediate family members, meaning their mothers, grandmothers, and sisters, may want to get tested, as about 20% of hereditary breast cancers are attributed to the BRCA mutations. If special circumstances, like adoption, have made a woman unsure of her family history, she may consider getting tested for peace of mind although it is not necessary if she has not developed breast or ovarian cancer.
Certain signs in a woman’s personal history can also prompt someone to get tested for BRCA 1 and BRCA 2 mutations. These signs include recurring breast cancer, breast cancer developed before the age of 50, cancer seen on both breasts, and the occurrence of both breast and ovarian cancer. Additionally, Ashkenazi Jews tend to have higher rates of BRCA 1 and BRCA 2 mutations and may want to consider getting tested, particularly if they have a family history of breast or ovarian cancers.
It is not recommended that children, even those with family histories of BRCA 1 or BRCA 2 mutations, undergo genetic testing.
What does it mean if I test positive for a BRCA 1 or BRCA 2 gene mutation?
If you test positive for the BRCA 1 or BRCA 2 gene mutations, it means that your risk for developing breast or ovarian cancer is dramatically increased, and that each of your children have a 50% chance of inheriting the gene as well. In the general population, around 12% develop breast cancer at some point in their lives, but women with harmful BRCA 1 or BRCA 2 mutations develop breast and ovarian cancer at far higher rates, and tend to develop it earlier and more aggressively. About 65% of women with BRCA 1 mutations and 45% of women with BRCA 2 mutations will develop cancer by age 70. Similarly, although only about 1.5% of women in the general population will develop ovarian cancer, about 17% of women with BRCA 1 mutations and 39% of women with BRCA 2 mutations will develop ovarian cancer. Ovarian cancer in women with BRCA 1 and BRCA 2 mutations also tend to appear earlier and be more aggressive.
The presence of BRCA 1 or BRCA 2 mutations in your body cannot determine with certainty that you will get cancer, nor can the test predict when cancer will occur if it does develop.
If I test negative for BRCA 1 and BRCA 2 mutations, can I still be considered high-risk for developing breast or ovarian cancer?
Yes. There are many different factors that can contribute to your risk of developing breast and ovarian cancer, and the BRCA 1 and BRCA 2 mutations are only one piece of the puzzle, accounting for just a small percentage of all breast and ovarian cancers. Only about 10% of breast cancer and 15% of ovarian cancer is caused by BRCA 1 and BRCA 2 mutations. Additionally, about 80% of heritable cancers are not caused by BRCA 1 or BRCA 2 mutations, which means that family history is still the most valuable tool we have for determining a woman’s risk of developing breast or ovarian cancers.
Women who have had one or more occurrences of breast or ovarian cancer in immediate family members are still considered high-risk for developing these types of cancer, even if they do not possess the BRCA 1 and BRCA 2 gene mutations. If you have a family history of breast or ovarian cancer, talk to your doctor about the steps you can take to prevent cancer from developing.