BRCA Mutations and Breast Cancer

By Priyanka Varma, Barbara Guido

BURLINGAME, Calif. Dec 7th, 2021

The name BRCA is an acronym for the “BReast CAncer gene”. There are two different BRCA genes, BRCA1 and BRCA2. They are tumor suppressor genes, aiding in repairing DNA breaks, which can lead to cancer and the uncontrolled growth of tumors. A mutation in the BRCA gene may render it ineffective in repairing the DNA break and preventing breast Cancer [1].

About 1 in 500 women in the United States has a mutation in BRCA1 and BRCA2 genes [2]. Individuals with BRCA1 or BRCA2 gene mutation or both have 72% risk of getting diagnosed with breast cancer during their lifetimes and a 50% risk by the time they turn 70 years of age, as compared to 7% risk of getting breast cancer in the general population in the United States [2, 3]. Besides BRCA, mutations in genes, including PALB2, TP53, PTEN, BRIP1, and others are also linked to Breast Cancer [3]. The harmful BRCA mutation can be passed down from either parent and there is a 50% chance of getting the same gene mutation [2]. There is a higher risk of getting a BRCA mutation in women with Ashkenazi Jews heritage [2]. Women with BRCA gene mutations also have an increased risk of cancer of fallopian tube, peritoneum, pancreas and skin (melanoma), while men who have BRCA gene mutations have an increased risk of cancer of breast, prostate and pancreas [4].

Although there are BRCA 1 and 2 direct to consumer tests which have made genetic testing more accessible, there can be some pitfalls to such testing. Some tests only assess for common BRCA mutations and do not sequence the whole BRCA gene to identify all BRCA mutations. A negative BRCA test does not mean a woman is not at increased risk of breast cancer and must be interpreted within the context of her family history and other risk factors. Women should talk to their provider to help interpret the results of the test.

A pertinent message when being tested for BRCA is to have an in depth conversation with your provider on the high risk associated with BRCA and the need for supplemental testing to diagnose breast cancer. Early detection of breast cancer caused in patients with BRCA mutations can successfully be treated in a vast majority of cases.

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