Thyroid Test Accurately Classifies Benign Fine Needle Aspirates

A thyroid cancer test can classify fine needle aspirates as benign with high accuracy. Fine needle aspirates increase the diagnostic accuracy of these very minimally invasive samples.

The test combines machine-learning vectors and statistical models applied to a database containing more than 1 billion genomic measurements from hundreds of fine needle-aspirate samples in order to identify genes that differentiate malignancy from benignity. A whole-genome analysis was performed to create the database.

At the 14th International Thyroid Congress, which was held in Paris (France) from September 11-16, 2010, the molecular diagnostics firm Veracyte (South San Francisco, CA, USA) presented initial data from a large-scale, prospective, multisite validation study.

Scientists found that in 66 fine needle-aspirate samples, including 43 indeterminate samples, the company's test had a negative predictive value of more than 95% compared to histopathology reviews, the gold standard of care. This means that with 95% accuracy, Veracyte's test could determine when a result was truly negative.

Veracyte will proceed to launch the test that is called Afirma initially in five to 10 academic sites with which it has been partnering while the test was being developed and through the validation study process.

In early 2011, the company will broaden the commercialization effort by making Afirma available through a larger number of community sites, "where those tests will really have a benefit," said Bonnie Anderson, CEO of Veracyte.

To start, the test will be available as a laboratory-developed test and its initial launch will be limited to the United States, although Veracyte is evaluating international opportunities.

Afirma, said Ms. Anderson, would address a US$500 million market just in the United States that continues to grow. While she could not say how much of that market the test could potentially capture, she said, "We think we can drive adoption through a significant percentage of that market."

A study describing the company's technology and the development of Afirma were published online in the September 2010 Journal of Clinical Endocrinology & Metabolism.

Using mRNA expression analysis, scientists including those from Veracyte, measured more than 247,186 transcripts in 315 thyroid nodules. The test achieved 96% negative predictive value and 84% specificity.

According to Ms. Anderson, the study offers proof that its approach to fine needle aspirates works, and will become the underpinning for future tests. Veracyte is performing early discovery work in lung cancer with the goal of developing a test for lung cancer fine needle aspirates, she said.

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