As personalized medicine reshapes healthcare, genetic counselors have become instrumental partners to providers.
Susan Caro, MSN, director of Family Cancer Risk Services for Saint Thomas Health, is a nurse practitioner credentialed as an advanced practice nurse in genetics, and provides cancer risk assessment and counsel about hereditary susceptibility to cancer and genetic testing. Caro said cancer risk counseling has come a long way since taking family risk assessments in the early 1990s.
“The object then was to try and select women at high risk of breast cancer and watch them carefully,” said Caro. After BRCA testing became available in 1994, Caro said patients were terrified of discrimination based on preexisting conditions. Fast-forward to 2015, and we’ve come a long way from pricey single gene tests to extensive panel tests for 20-40 genes.
“For the first decade it was, ‘Who do we test?’ and then, ‘What do we do with it?’” Caro said.
Milestones in Genetic Testing
Universal acceptance of genetic testing has been a huge leap for the medical community in recent years. A 2013 Supreme Court ruling prohibiting the patent of BRCA1 and 2 testing marked a milestone that’s allowed for more affordable testing options.
Caro said the development of panel tests through next generation sequencing also have allowed for a massive reduction in testing costs. But despite their success, large panel tests aren’t without their limitations.
“One of most important things we tell patients is that this changes every day,” Caro said of panel testing. “The information we share today wasn’t even available five years ago so oftentimes we don’t have enough information to know if there’s been a mutation. The most important thing I share is that this will change with time. If we don’t answer questions now, we need to keep asking and revisit every year or two.”
That’s because many genetic variances are still of unknown significance, meaning providers lack the evidence to know if a genetic change affects the function of the gene. Caro also warns that the absence of a mutation might actually be a technological oversight, as new genes are added to the panels and technological advances improve detection of mutations.
Rules of Genetic Counseling
As genetic testing becomes more prevalent, Caro said lab selection is critical.
“The choice of lab really makes a difference, as one lab a might go deeper into the intron, or another lab might have seen a genetic variation so often that they characterize it as nothing,” Caro said.
Add to that concern the growing availability of do-it-yourself genetic tests once available only through providers. Recently, Silicon Valley-based Color Genomics launched their website offering saliva test kits for $249 – one-tenth the price of many tests now on the market. Results include an analysis of BRCA1 and BRCA2, plus 17 other cancer-risk genes. While controversial, the tests are becoming mainstream thanks in part to the Supreme Court’s 2013 BRCA ruling.
More choices for patients and providers means genetic counselors are working overtime to educate all audiences on the importance of counseling. Caro said physicians should strongly urge patients to first meet with a genetic counselor to avoid being blindsided, disappointed or surprised by results.
“Primary care providers are being marketed to directly by labs, saying that this is an appropriate test,” Caro said. “That’s great as long as someone’s talking to the patients about it beforehand. It becomes a clinical and emotional emergency for counselors when someone in the community gets test results back without having had appropriate discussions in advance.”
Pre-testing conversations typically take two hours and include family history and high-level genetic education. Sometimes conversations result in a delay, while other patients opt to not test.
Which begs the question … Who should be tested? Experienced counselors like Caro, who have often caught the unexpected in panels, have a very low testing threshold.
“Sometimes we might find something that gives us the opportunity to prevent cancers in relatives,” she said. “We get excited about finding something because it helps us answer a question or make a difference for someone who’s at risk. More information means more choices, and a lot of patients are willing to take that risk.”
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