“Genetic testing has entered a new era and our older paradigms are no longer sufficient.” That’s the context for a new study in the journal Oncology, “What’s New in Genetic Testing for Cancer Susceptibility?” While covering a range of issues, the article identifies opportunities and challenges that genetic testing is bringing to the clinic as it becomes more affordable, available, and instrumental in an expanding number of areas of medicine. Below are some of the key points that underscore the authors’ conclusion: it is imperative we “find every mutation carrier for every hereditary syndrome before the disease occurs,” to enable preventative screening or treatment. This is an important part of the promise of precision medicine.
- Providers are key to accelerating access to testing. While genetic testing of the BRCA1 and BRCA2 genes has been around for more than two decades, according to the report, more than 90 percent of people with a mutation in one of these two genes “remain unaware of their status and are mismanaged.” Why? The report suggests that providers do not identify patients at risk of having a hereditary susceptibility to cancer “either because there is insufficient time to take a thorough family history, because they lack the genetics expertise to analyze the histories they do take, or because they are unfamiliar with the genetic testing guidelines.” In the case of the BRCA1 and BRCA2 genes, recent studies cited by the report “highlight a serious problem — namely, that many women who meet criteria for testing may not receive a recommendation for testing from their physician.”
- High-quality genetic counseling needs to become scalable. Genetic counseling is an invaluable but time-consuming aspect of testing. Without counseling, many patients wouldn’t know how to interpret their results or act on them. As the number of genetic tests continues to grow, there are not enough genetic counselors to handle the volume of patients using the traditional pre-test genetic counseling model. Color’s genetic counselors have also written about ways to increase efficiency in genetic counseling using software. In order to reach more patients, the report suggests, “the solution may well lie in changing our model of counseling.” Since most patients will have a negative test result that will be reassuring, only patients who are positive or who are negative but still have a high risk of a hereditary predisposition would be seen by a genetic counselor.
- We are reconsidering population-based screening for adults. While every baby born in the U.S. is screened for genetic diseases that may impact them during infancy or childhood, we don’t screen adults for conditions where interventions exist. Advances in genetic testing are presenting powerful arguments to start. As the report states, “Today, genetic testing is inexpensive, panel testing is ubiquitous, and management strategies exist to find cancers at an earlier and more treatable stage.” Yet current testing criteria in national guidelines leave many patients with mutations ineligible for testing coverage by health insurance. This results in a “failure of prevention”, noted by renowned researcher and discoverer of the BRCA1 gene, Dr. Mary-Claire King. “Furthermore”, as the report states, “there is increasing recognition of wide phenotypic spectra for any given mutation, which may have some overlap with other hereditary syndromes. Thus, when we do a panel test that includes a colorectal cancer gene in a patient with a suspected hereditary breast cancer, we are in many ways doing population-based screening…” Taken together, we have already begun the process of broader genetic screening and we should be engaging in strategies that identify all people who would benefit from it. Dr. King suggests that every woman should be screened at about age 30.
Want to get a deeper dive? Here’s the full article.