Years ago, when I first learned that genetic testing could help screen for some cancers, such as breast, ovarian and bone, it seemed like a no-brainer to get this testing done. Now I know better; genetic testing is a helpful tool that can help you assess your risk for certain kinds of cancer, but it's not recommended for everyone. Senior genetic counselor Kerry Kingham, a clinical assistant professor affiliated with the Cancer Genetics Clinic at Stanford, explains why this is the case in a recent Q&A with BeWell@Stanford.
Cancer can be "hereditary" or "sporadic" in nature, Kingham says. Hereditary cancers, such as the forms of breast cancer related to a mutation in the BRCA1 or BRCA2 genes, are associated with an inherited genetic mutation. In contrast, sporadic cancers arise independent of family history or other risk factors. Since genetics testing detects gene mutations, it can only be used to help screen for the mutations that may lead to forms of hereditary cancer.
Kingham elaborates on this point, when it makes sense to get genetic testing, and what the results may mean in the Q&A:
Twelve percent of women in the U.S. develop breast cancer; it is a common disease. Yet, only five to ten percent of these women will develop breast cancer because of a hereditary gene mutation.
The best step to take prior to deciding whether or not to proceed with genetic testing is to meet with a genetic counselor. Your doctor can provide a referral. The genetic counselor will take a three generation family history, discuss the testing that might be indicated for you or a family member, and explain the risks and benefits of the testing. They also discuss the potential outcomes of the testing: whether a mutation is found, a mutation is not found, or there are uncertain results. Even when a genetic test is negative, this may not mean that the individual or their family is not at risk for cancer.
At this point you may be wondering: Why bother with genetic testing if it's only useful for hereditary cancers and a negative test result is no guarantee you're risk-free? Kingham's closing comment addresses this question nicely: "I would say that your genes don’t change – they are what they are, and knowing what is in our genes can often help us learn how to take better care of our health."
Previously: Stanford researchers suss out cancer mutations in genome’s dark spots, Angelina Jolie Pitt’s New York Times essay praised by Stanford cancer expert, NIH Director highlights Stanford research on breast cancer surgery choices and Researchers take a step towards understanding the genetics behind breast cancer
Photo by Paolo