Veracyte, Inc. (NASDAQ: VCYT) today announced new data suggesting the potential to enhance the performance of the Afirma Gene Expression Classifier in thyroid cancer diagnosis by combining the test's proven RNA expression-based capabilities with gene variant and fusion information – all on a single, robust RNA sequencing platform. Such enhancements could help to further reduce the number of patients who undergo unnecessary surgery when their thyroid nodules are not clearly benign or cancerous (i.e., indeterminate) following routine cytopathology evaluation.
Veracyte scientists presented the findings today in a poster session at the 86th Annual Meeting of the American Thyroid Association, being held in Denver through September 25. Six additional posters are being presented at the ATA meeting by external researchers and underscore the Afirma GEC's role as a new standard of care in thyroid cancer diagnosis.
In the Veracyte study, company researchers used RNA from 88 thyroid nodule patient samples for which a surgical pathology diagnosis was known to train (with 58 samples) and test (with 30 samples) an enhanced version of the Afirma GEC. Using advanced machine-learning techniques, Veracyte leveraged an RNA sequencing platform to combine the genomic test's RNA gene expression-based algorithm with gene variant and fusion information. The result was an enriched classifier that yielded an overall area under curve (AUC) of 0.88, with a sensitivity of 93 percent and a specificity of 80 percent.
"Numerous efforts have been made to diagnose indeterminate thyroid nodules using cancer-associated DNA mutation and fusion information. However, research is increasingly showing the limitations of this approach in clinical practice because such gene alterations are found in both cancerous and benign patients," said Giulia C. Kennedy, Ph.D., Veracyte's chief scientific officer, who presented the new data. "We believe that our study is the first to show that, using a powerful machine-learning approach, RNA expression and gene variant and fusion information can be combined into one molecular test that is run on a single RNA sequencing platform to provide clinically useful information. Ultimately, this should help more thyroid nodule patients avoid unnecessary surgery. Efforts are already underway to apply this approach to a larger study cohort."
Other Afirma GEC-related posters presented at the ATA conference included a review of long-term outcome studies for the Afirma GEC. Among the three studies with over a year of follow-up, the majority of patients – 85 percent – who had Afirma GEC-benign results following indeterminate cytopathology continued to avoid surgery and be monitored instead. Additionally, researchers from Scripps Clinic/Scripps Green Hospital reported that their use of the Afirma GEC during a five-year period led to a significant reduction (23.6 percent) in surgery recommendations for indeterminate thyroid nodules.
"Thyroid cancer has become a poster child for overtreatment in medicine," said Bonnie Anderson, Veracyte's president and chief executive officer. "The evidence presented at the 2016 ATA conference shows that the Afirma GEC is truly changing care for patients, helping them avoid surgeries they do not need, along with the lifelong implications of that surgery, while also removing costs from the healthcare system. We believe our novel approach also holds promise for providing additional clinically useful cancer-related information to physicians – in thyroid and potentially other cancers."