Around 1 in 10 cases of female breast cancer is due to a faulty gene passed through families from one generation to the next.
Here are 5 common myths about hereditary breast cancer.
Myth 1: Breast cancer gene mutations only cause breast cancer.
BRCA1 and BRCA2, which stand for Breast Cancer gene 1 and Breast Cancer gene 2, are the most common genes involved in hereditary breast cancer. A mutation in these genes raises the lifetime risk of breast cancer to as high as 85% but also increases the risk of ovarian, prostate and pancreatic cancer. Other gene mutations with strong links to breast cancer (such as TP53 gene in Li-Fraumeni syndrome and CDH1 gene in Hereditary Diffuse Gastric Cancer) are associated with increased risk of endometrial, thyroid, soft tissue, adrenal, brain and gastric tumours. For this reason, it is worthwhile knowing all the cancers that have occurred in the family.
Myth 2: I only need to pay attention to medical history on my mother’s side.
Faulty genes can be passed down from the maternal and paternal side of the family, including the genes involved in hereditary breast cancer. In fact, male breast cancer is much more likely to be associated with genetic mutations than female breast cancer. Therefore, it is important to check both sides of the family history.
Myth 3: I will automatically get breast cancer if I test positive for a mutation.
Having a gene mutation does not guarantee you will develop cancer, but it does significantly increase your risk. Knowing you have a mutation allows you to work with your doctors to develop a personalised plan for screening and prevention.
Myth 4: There is no need to worry about breast cancer if I test negative for a mutation.
9 out of 10 women who develop breast cancer do not have hereditary breast cancer. The biggest risk factors are being a woman and growing older. Therefore, it is important to be breast aware and have biennial screening mammograms from the age of 50, even if there is no family history of breast cancer.
Myth 5: I already have breast cancer, so genetic testing is unnecessary.
Knowing your genetic test result can guide cancer treatment decisions such as the choice of surgery (lumpectomy versus mastectomy) and/or type of chemotherapy. It can also inform you of the risks for other cancers (such as ovarian cancer), and help your family learn about their risks.
A referral to a family cancer clinic for genetic counselling and testing is warranted if you have these ‘red flags’ in your family history.
Angelina Jolie, a BRCA1 carrier, took steps to reduce her risk of breast and ovarian cancer by having a preventative double mastectomy, as well as the removal of her ovaries and fallopian tubes.
“Cancer is still a word that strikes fear into people’s hearts, producing a deep sense of powerlessness. But today it is possible to find out through a blood test whether you are highly susceptible to breast and ovarian cancer, and then take action.” - Angelina Jolie
