Can my 23andme data tell me about breast cancer risk?

You have heard of Angelina Jolie getting a preventive surgery to significantly reduce the risk for breast cancer. This, along with the fact that you have a first degree relative with breast cancer, has probably left you wondering if you should get a genetic test for breast cancer. So, what exactly is a genetic test for breast cancer and do you really need it? Will my 23andme BRCA status help me predict my risk for breast cancer?

Genetic testing for breast cancer identifies specific genetic variants, like 23andme BRCA gene variants, which have been associated with an increased risk for breast cancer.

23andme BRCA gene-related reports may be used for:

  • Identifying predisposition for breast cancer
  • Response to chemotherapy
  • Genetic prognosis determination
  • Breastfeeding duration and risk of breast cancer
  • Breast size and risk of breast cancer
  • Menopausal hormone therapy and risk of breast cancer

The benefits of genetic testing are that it can be used for unique screening protocols which will aid in early detection of breast cancer or help in identifying high risk for breast cancer. It is important to note that only 5 to 10% of breast cancer incidences are due to inherited mutations.

According to The National Comprehensive Cancer Network Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Genetic/Familial High-Risk Assessment (version 2017): Breast and Ovarian cancer were developed with the intent to

(1) Serve as a resource for healthcare providers to identify individuals who may benefit from cancer risk assessment and genetic counseling;

(2) Provide genetic counselors with an updated tool for the assessment of individual breast and ovarian cancer risk and to guide decisions related to genetic testing;

(3) Facilitate a multidisciplinary approach in the management of individuals at increased risk for hereditary breast and/or ovarian cancer.

Who Should Opt for Genetic Test for Breast Cancer?

You should consider genetic testing if you meet any of the following criteria

  • Early onset breast cancer- less than 50 years.  
  • Both Breast and ovarian cancer
  • Multiple breast cancers
  • Triple-negative breast cancer
  • Close relatives on the same side of the family with the same (or related) cancers
  • You have an Ashkenazi Jew ancestry

Genetic surveillance of women, with the accent on the ethnic background, age, family history and in another appropriate clinical context will help in stratifying women into high-risk groups so that there is increased surveillance, an extension of chemoprevention or the utilization of risk reduction surgery.

You can now find out if you carry the variants that increase breast cancer risk from Xcode’s Breast Cancer report by uploading your 23andme or any other ancestry DNA raw data. You can read more about the Xcode Breast Cancer report here.

Get your BRCA1/2 status report from your DNA raw data now.


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