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Twenty years ago, using genetic testing to confirm diseases such as cystic fibrosis (CF) didn’t accomplish much. There was no cure, and any treatments that did exist were based on pancreatic enzymes rather than an underlying molecular defect.
The diagnostic landscape is vastly different today, with genetic defects directing clinicians to highly specific treatments based on genotype. In the case of CF, recent drugs are not only targeted to mutation types, but if you don’t know the mutation type you cannot prescribe the relevant drug.
Test. Confirm. Consult.
This is where genetic companion diagnostic tests have been a boon for precision medicine, especially for those therapies that treat underlying causes versus symptoms. The bottom line of genetic companion diagnostics is that you are testing the underlying genetics of a patient to help guide the most appropriate treatment decisions.
Genetic testing also makes sense if doing so uncovers a hereditary mutation. Take the BRCA1 and BRCA2 tumor suppressor genes. A hereditary mutation here points to a very high lifetime risk of developing breast cancer. Even in the case of non-hereditary disease, sequencing tumors can direct clinicians to the right treatments when they are available.
Against this complex backdrop, the benefits of genomics services offered by a diagnostics provider can be substantial. In my experience, even clinicians from hereditary oncology groups who run these tests every week, find it helpful to speak to a counselor to ensure they’re understanding genetic test results. This is important to them because the next conversation they have is either with the genetic counselor or the patient. And in smaller systems or community cancer centers, there may be few, if any, genetic counselors on staff, so offering these services is critical.
A genetic counselor employed by a diagnostics lab can help a clinician to:
- Alter a treatment plan
- Understand risk for the specific patient
- Explain the implications of various mutations
- Clarify variants of unknown significance (VUS)
A less tangible but often equally important outcome of genetic counseling is that it increases the clinician’s confidence. Genetic testing at its current volume has only been part of healthcare for about a decade, so even experienced physicians may need a little assistance keeping pace with the advances.
Finding the right genetics testing expertise
Whether you are part of a local, regional, or national health system, it’s important to qualify a genetic diagnostics lab for the right capabilities. Based on 30 years of experience as a genetic counselor, I’d want two things.
- A broad, comprehensive test menu. I wouldn’t expect any one lab to have every genetic test, because that’s nearly impossible today. But the more capabilities the partner has, the less you have to deal with all the smaller, specialty labs that may be unable to offer counseling beyond a very narrow set of tests. More comprehensive labs also can help you streamline and consolidate providers, so you’re not sending out to 50 or 100 different labs, but perhaps dealing with only a dozen.
- Expert genetics support. Does the lab you’re considering have genetics subject matter experts that your clinicians, your genetic counselors, and their patients can talk to about genetic tests and their results? And can they explain things in clear, simple terms that patients and caregivers can understand? Regardless of how many genetic counselors may sit within a health system, it remains invaluable to have expertise in a testing partner. Even genetic counselors often need assistance in interpreting a result: how common or unusual it is, or what it may point to. This expertise should extend to clinical medical oncologists on staff, as well as specialists in neurology, OBGYN, pediatrics, and other fields.
The right test—and expertise—at the right time
I’ve seen trends in the in-house vs reference testing mix come and go. There was a time when every health system wanted to bring all testing in house, including genetic testing. But it turns out that the latest technologies are very expensive to buy and maintain, and unless your system runs significant volume for certain tests, the economic case isn’t robust. Stat and core lab work may well remain within the health system walls, but many health systems have more recently taken the strategic decision to collaborate with a genetic testing lab.
When and if you make this decision, however, remember to choose a lab that supports everything you need to deliver the full value of your genetic testing program. As many systems have discovered, that’s about a lot more than the test.