Approximately 70% of women with a BRCA1 or BRCA2 gene mutation will develop breast cancer by the age of 80, according to a study published in 2017 in the Journal of the American Medical Association. The FDA recently granted approval to genetic testing company 23andMe to sell at-home kits that test for these very mutations associated with a higher risk of breast cancer. But are these results reliable, or even useful?
With FDA approval, the public can be assured that 23andMe’s test provides accurate and valid results. But the bigger concern lies in the interpretation of these results. There are several genes aside from BRCA1 and BRCA2 that increase the risk of breast cancer anywhere from 20%–85%, according to the Susan G. Komen Breast Cancer Foundation. Therefore, negative results do not necessarily guarantee a low risk of developing breast cancer. An individual may gain a false sense of reassurance, which may negatively impact health-seeking behaviours such as doctor’s visits for cancer screening and early diagnosis. Furthermore, those who test positive will not be linked to proper coping services, such as genetic counselling; this could result in a negative psychological impact and increase the risk of falling victim to mental health issues like depression or anxiety. Essentially, in losing a key mediator (the doctor) between results and interpretation, we risk delivering data to people who might be ill-prepared to hear it.
That being said, 23andMe is a relatively affordable and convenient way to evaluate your breast cancer risk, especially if you have a family history of it. It also allows consumers to bypass all of the barriers associated with test eligibility in the first place. The bottom line is, genetic testing represents much more than a simple positive or negative result, and we cannot lose sight of this as we introduce non-traditional options of healthcare delivery.
GlobalData (2017). PharmaPoint: HER2-Positive Breast Cancer – Global Drug Forecast and Market Analysis to 2025, June 2017, GDHC151PIDR. https://pharma.globaldata.com/Reportsview.aspx?DocID=53577
GlobalData (2016). PharmaPoint: HER2-Negative/HR+ and Triple Negative Breast Cancer – Global Drug Forecast and Market Analysis to 2025, December 2016, GDHC139PIDR. https://pharma.globaldata.com/Reportsview.aspx?DocID=50243
GlobalData (2016). EpiCast Report: Breast Cancer (HER2+, HER2-) – Epidemiology Forecast to 2025, December 2016, GDHCER133-16. https://pharma.globaldata.com/Reportsview.aspx?DocID=50386