AAO-HNS14: New Assessment Methods for Thyroid Nodules

The test holds great potential to reduce the number of unnecessary diagnostic surgeries, Dr. Witt said. Traditionally, 15% to 25% of nodules are classified as indeterminate, and subsequently, approximately 80% of those are found to be benign.

Diagnostic thyroid surgeries come with drawbacks: They cost $6,000 to $10,000, involve the possibility of complications, often mean lost time from work and difficulty meeting daily responsibilities, and cause anxiety and possible iatrogenic hypothyroidism and lifelong medications, he said. “One could say in retrospect that most of these patients underwent unnecessary surgery,” he said. “We do have a better test, and we have it now.”

Across many studies, the negative predictive value of the Afirma test has been approximately 95% for FLUS and 94% for FN.

Context is Everything

Greg Randolph MD, associate professor of otology and laryngology at Harvard Medical School in Boston, underscored the importance of using genetic tests in the right context. The Afirma GEC works best in categories with a low prevalence of malignancy, for example, and the Asuragen oncogene panel works best when prevalence is higher.

He also emphasized, along with the others, that there is “tremendous, tremendous divergence” in the prevalence of malignancy from center to center—25% prevalence in one center for one type of nodule might be almost 50% in another. The correct use of the testing depends on those numbers.

Generally, nodules that are in the Bethesda categories of atypia of undetermined significance (AUS), FLUS, and FN would be more likely to undergo GEC testing. And those in the SMC category would be better suited for the oncogene panel. “[That] is how these tests are typically applied,” Dr. Randolph said. “Most would agree. There’s some debate, but most would agree.”

These tests are not the only factor to consider, though. In cases involving a well-informed patient who wants surgery and has a higher chance of malignancy due to vocal fold paralysis, a suspicious ultrasound finding, or other factors, surgery might be warranted with no need for testing.

He also stressed the importance of patient consultation in cases of thyroid surgery. “I think it’s important to take time with these patients,” he said. “Every patient that I see who I know will need surgery, I force them to see me twice. This is not the most convenient or time-efficient way to run a practice, but it allows you to see the patient initially and see the patient a second time for a pre-operative visit, and it allows an agenda matching. With that amount of time, you never get a patient saying, ‘You told me I had a tumor. I thought it was a cancer.’”

Ready for Mainstream?

Edmund Pribitkin, MD, vice chair of otolaryngology-head and neck surgery at Jefferson Thyroid and Parathyroid Center in Philadelphia, said that while the rate of thyroid cancer diagnoses has been increasing, the mortality rate has been level. “People aren’t dying, necessarily, of the disease, even though it’s being discovered more often in folks,” he said.

So when otolaryngologists are considering expensive genetic testing, they need to make sure it’s worth it. “If we’re going to do this testing, we need to make sure that it affects our decision making in terms of caring for folks,” he said. “Identification of risk does not really guarantee a benefit of treatment.”