The Role of Genetic Testing in Assessing Breast Cancer Risk

Medical professionals recommend that only individuals with a high risk for BRCA mutations (genetic mutations that heighten the risk of developing breast cancer) should seek genetic testing. This is because, without the presumed risk, it has been determined that the odds of possessing breast-cancer-causing mutations are extremely low. Individuals are considered to be at high risk for BRCA mutations if they have a family history of breast cancer before age 50, male breast cancer, more than one relative on one side of the family with breast cancer, recurrence of breast cancer, ovarian cancer, Ashkenazi Jewish heritage, or men on one side of the family being diagnosed with prostate cancer, ovarian cancer, melanoma, or pancreatic cancer.  

 Before testing, it is crucial to meet with a genetic counselor or healthcare provider to discuss your personal and family history of cancer and assess whether testing is appropriate for you. The counselor explains the benefits, risks, and limitations of genetic testing and helps you understand what the results might mean. Testing is usually done with a sample of blood or saliva, in which medical professionals search the DNA for anomalies in the BRCA gene that could influence breast cancer development. However, different forms of this test can examine other genes that may influence breast cancer. Each of these mutations may carry varying degrees of risk, and testing for them can provide a more comprehensive genetic risk profile. After a provider obtains the results, they will consult the patient about the best way to move forward. Genetic testing is generally highly accurate, but it must be paired with proper medical guidance to translate the results into actionable steps.

A positive test result indicates the presence of a mutation associated with a higher risk of developing breast cancer. Nevertheless, if a patient tests positive, this does not mean that they will develop cancer, as it simply reflects an increased risk compared to the general population. After a positive result, the patient and their healthcare team will concur a plan on how to manage the patient’s risk for developing breast cancer. This plan, depending on factors such as the patient’s age and medical history, could include frequent screening, different forms of screening, preventative medication, or preventative surgeries such as a mastectomy (removal of the breast) or oophorectomy (removal of the ovaries).

True negatives occur when medical professionals find no evidence of gene abnormalities, indicating the patient has a normal risk of developing breast cancer. Negative test results can happen without being considered “true negatives”, however, as patients who test negative can still have an elevated risk of breast cancer development due to other genetic or environmental factors. Additionally, despite being rare, an uncertain test result can occur, which stipulates a gene abnormality that doctors cannot diagnose. Oftentimes, in this case, it is helpful to receive a second opinion from another medical professional or explore additional testing options.