How DNA Testing for Health Can Help You Reduce Your Risk for Breast Cancer

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MyHeritage recently added 7 new health reports to the MyHeritage Health test, bringing the total of comprehensive health reports the test offers to 42. One of the health reports that was enhanced as part of this update was the BRCA report: an essential source of information on women’s risk of developing breast cancer. This update has made MyHeritage Health the industry leader in BRCA variant screening, providing the most comprehensive report for hereditary BRCA cancers among the leading consumer brands.

Breast cancer is the most common cancer in women all over the world. It accounts for a quarter of all cancers, striking 1 in 8 women in the United States alone. There are a number of factors that may contribute to a given individual’s risk of developing this disease — and genetics is one of them.

In this post, we’ll take a look at the various genetic factors of breast cancer risk and learn how this information can empower women and men to take charge of their future health.

HBOC syndrome and BRCA

In 5–10% of breast cancer cases, genetics are not only a contributing factor, but the strongest contributing factor. These cases are attributed to monogenic (single-gene) conditions that fit under the umbrella of a condition known as hereditary breast and ovarian cancer (HBOC) syndrome.

People with HBOC have a significantly increased lifetime risk to develop breast cancer and ovarian cancer. The most common HBOC by far is related to a disease-causing variant in the BRCA1 or BRCA2 gene. Women who inherit one of these variants have a lifetime risk of 72–82% for breast cancer and up to 44% for ovarian cancer.

Breast cancer is not a female-only condition, though. Men with a BRCA variant are also at risk to develop breast cancer. Having a BRCA2 variant increases a man’s lifetime risk to develop breast cancer about 80-fold.

While BRCA1 and BRCA2 variants are the most common causes of HBOC, there are other genes associated with the syndrome as well, such as PALB2 (for which there is also a report in the MyHeritage Health DNA test).

Regardless of the particular gene, all HBOC syndromes have similar characteristics, which may include:

      • Cancer diagnosis at a relatively young age
      • Cancer that presents on both sides
      • Male breast cancer
      • Specific tumor pathology
      • Second primary cancer

While the statistics on HBOC syndrome sound rather grim, it doesn’t have to be a death sentence. When the condition is diagnosed before cancer develops, there are clear medical management protocols for preventative screening and early treatment that can vastly improve prognosis.

That’s why it’s so important to get thoroughly screened. There are many variants in the BRCA1 and BRCA2 genes that can cause HBOC, and the more variants examined, the less likely you are to have a variant that goes undetected. The MyHeritage Health test now examines 103 BRCA variants, providing the most comprehensive report for hereditary BRCA cancers among the leading consumer brands.

In most healthy individuals without a personal or family history of hereditary BRCA-associated cancers, this offers very comprehensive coverage, since the remaining variants the MyHeritage Health test doesn’t review are extremely rare. However, people who do have a history of BRCA-associated cancers in their family have a greater risk of carrying a rare variant. For this reason, MyHeritage withholds hereditary BRCA cancers and PRS breast cancer reports for people who report having this type of history. We strongly recommend that these individuals speak with a doctor and/or genetic counselor to determine if they should take a clinical-grade or diagnostic test for all BRCA variants.

Consult with your doctor or genetic counselor about your genetic risk for breast cancer
Consult with your doctor or genetic counselor about your genetic risk for breast cancer

Should you test for BRCA variants if you have no family history?

While it’s true that people with strong personal or family history of hereditary BRCA cancers are more likely to carry cancer-associated variants, there are also many, many people who don’t have that kind of history and still have a genetic risk for breast cancer. Some estimates suggest that up to 50% of the population may carry such variants despite having a history that doesn’t meet current clinical testing criteria — or no history at all. That means that up to 50% of the population could be at risk and not know about it.

Therefore, it’s a good idea to test for BRCA variants even if you don’t have a family history of these types of cancers.

Polygenic risk of breast cancers

So what about the remaining 90–95% of breast cancers that are not caused by HBOC syndrome?

We know that there are families with a history of breast cancer but no HBOC syndrome, and large-scale, genome-wide association (GWAS) studies suggest that people with breast cancer have a different variant distribution than those without. What this tells us is that genetics does play a role in at least some cases of breast cancer that are not associated with HBOC syndrome.

This is why MyHeritage’s Polygenic Risk Score (PRS) for breast cancer is so valuable. Polygenic risk scores examine a wide range of genetic variants that, when found together, are associated with elevated risk for developing a condition. Breast cancer risk identified by PRS may not be as high as the lifetime risk for breast cancer associated with an HBOC, because other factors — such as a person’s environment, lifestyle choices, and overall health play a larger role in whether they will actually develop breast cancer. 

That means that if you receive a PRS result that indicates that you’re at increased risk for breast cancer, you may be able to mitigate that risk by making changes to your lifestyle. You can also speak to your healthcare provider about screening protocols and other preventive measures.

What can you do to prevent developing breast cancer?

  • Knowledge is power. Take a DNA health screening test such as MyHeritage DNA Health to get an idea of what your risk is.
  • Speak to a genetic counselor to determine whether any additional screening might be a good idea in your case.
  • Speak to your healthcare provider about your family history, and be sure to provide as much detail as you can: if someone in your family had breast cancer, how old were they when it developed? Was it on one side or both? Did that person have any other cancers?
  • Decrease other contributing risk factors. Especially if you discover an elevated polygenic risk for developing breast cancer, lifestyle changes such as weight loss, quitting smoking, or cutting back on alcohol consumption can help substantially decrease your risk.

Getting support

Learning that you are at higher risk for developing cancer can be scary and overwhelming. If you’re undergoing breast cancer testing or treatment, it’s crucial that you get the support you need, and there are many organizations providing different types of support — from advocacy to research to emotional and financial support.

The Susan G. Komen Foundation is an international organization that works around the globe to encourage screening for early detection and ensure access to quality care and treatment.

The Susan G. Komen Foundation funds Breast Cancer research as well as offering support to those with breast cancer
The Susan G. Komen Foundation funds breast cancer research and sponsors community initiatives to support those with breast cancer

Breast cancer prevention is the primary focus of the five organizations featured here. For emotional support, sometimes individuals find it more helpful to hear from those who have experienced breast cancer themselves. The American Cancer Society hosts a Facebook page for just this purpose. There are also many other support groups on Facebook — simply search “breast cancer.” 

Ultimately, knowledge about breast cancer — your history, your risk, your options — is the best way to address this global health issue. 

To learn about your own genetic risk for developing this disease, order a MyHeritage Health test today.

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