The Evolution of Genetic Testing from Focused Testing to Panel Testing and from Patient Focused to Population Testing: Are We There Yet?

The field of cancer genetics has evolved significantly over the past 30 years. Genetic testing has become less expensive and more comprehensive which has changed practice patterns. It is no longer necessary to restrict testing to those with the highest likelihood of testing positive. In addition, we have learned that the criteria developed to determine who has the highest likelihood of testing positive are neither sensitive nor specific. As a result, the field is moving from testing only the highest risk patients identified based on testing criteria to testing all cancer patients. This requires new service delivery models where testing can be mainstreamed into oncology clinics and posttest genetic counseling can be provided to individuals who test positive and those with concerning personal or family histories who test negative. The use of videos, testing kiosks, chatbots, and genetic counseling assistants have been employed to help facilitate testing at a larger scale and have good patient uptake and satisfaction. While testing is important for cancer patients as it may impact their treatment, future cancer risks, and family member's cancer risks, it is unfortunate that their cancer could not be prevented in the first place. Population testing for all adults would be a strategy to identify individuals with adult-onset diseases before they develop cancer in an attempt to prevent it entirely. A few research studies (Healthy Nevada and MyCode) have offered population testing for the three Centers for Disease Control and Prevention Tier 1 conditions: hereditary breast and ovarian cancer syndrome, Lynch syndrome, and familial hypercholesterolemia finding a prevalence of 1 in 70 individuals in the general population. We anticipate that testing for all cancer patients and the general population will continue to increase over the next 20 years and the genetics community needs to help lead the way to ensure this happens in a responsible manner.