Breast Cancer and the Value of Genetic Testing

Genetic testing for breast cancer is a topic on many women’s minds as there’s an increasing amount of information and news coverage about this important cancer screening tool. To understand the value of genetic testing, we need to define the purpose – that is to assess whether an individual is at average or high risk of developing breast cancer, and in some situations, other cancers like ovarian or pancreatic cancer.  

Of all the women diagnosed with breast cancer, only about 5% are related to a gene mutation. The vast majority of breast cancers are random; therefore we do not recommend genetic testing for all women who are diagnosed with the disease. Women with a family history of breast cancer have a higher risk of also getting breast cancer at some point in their lifetime, so a thorough family history is the next step. We want to know how many women in the family who have had breast or ovarian cancer, the closeness of those family members, their ages at the time of diagnosis, as well as other types of cancers, particularly prostate and pancreatic cancers.

We also look at how many individuals on a single side of the family – not both sides – have been diagnosed with cancer. Based on whether we see a trend or if there are multiple cancers in the same side of the family, these women could benefit from genetic testing to determine if they harbor a gene that would increase their risk of breast cancer.

Another trigger for genetic testing could be the age of a breast cancer diagnosis. The average age of a breast cancer diagnosis is 62. Women who have a much earlier diagnosis – like in their 30s, 40s or 50s – may also benefit. Certain gene mutations can increase cancer risk by upwards of 40 to 60%, which is significant over the course of a lifetime. Genetic testing is valuable in that in gives your health care team important information they can use to protect your health, and it gives you options about what proactive steps to take. Women at different stages of life often have different perspectives on whether to seek definitive treatment or opt for careful watching.

For example, a woman with breast cancer in one breast who discovers she carries a gene mutation that predisposes her to additional cancer risk may decide to have a radical mastectomy followed by a complete reconstruction. Other women may choose a more conservative approach, choosing an enhanced screening schedule that will keep a closer watch on any potential changes. In these cases, a future cancer will likely be found in its early stages when treatment is most effective.

I do want to point out that direct to consumer genetic testing is not the same as testing available through your healthcare provider. Along with not knowing how your genetic information is stored and shared, at-home tests may provide specific details, but do not offer the thorough interpretation of results and the professional guidance that comes with working with certified genetic counselors. This information coupled without knowledge of a person’s medical history and clinical diagnosis may lead to unnecessary and/or potentially harmful treatment or interventions.

That’s why as part of our comprehensive approach to breast health, we work hand in hand with CHI Memorial’s Cancer Risk and Survivorship Center, which offers cancer risk counseling to help people better understand how their family history of cancer might affect their individual risk. Genetic testing and risk evaluation are complicated and different for every person. Having a seasoned professional to help answer questions and guide your decision making is invaluable. Ultimately, if you meet the criteria for breast cancer genetic testing, there really are no negatives to having a clearer understanding of your cancer risk – giving us time to plan and prepare and take the very best care of your health.

Learn more about genetic testing and counseling available at CHI Memorial’s Cancer Risk and Survivorship Center by calling (423) 495-6744. To schedule an appointment with Dr. Williams at CHI Memorial Breast Care Associates, please call (423) 698-0304.