Combined Platform Test Achieved High Negative Predictive Value (NPV) of 94% and Positive Predictive Value (PPV) of 74%
PDI, Inc. (NASDAQ: PDII) subsidiary, Interpace Diagnostics, announced today new data supporting the use of combination platform testing with ThyraMIR™, the first and only microRNA expression classifier, and ThyGenX™ Thyroid Oncogene Panel, a DNA and RNA mutational analysis, to improve thyroid cancer diagnosis. The study, presented at ENDO 2015: The 97th Annual Meeting & Expo of the Endocrine Society held March 5-8, 2015 in San Diego, CA, showed that benign or malignant nodules can be identified with high sensitivity and specificity resulting in clinically actionable negative predictive value (NPV) at 94% and positive predictive value (PPV) at 74%. The effect of combining nucleic acid sequencing with a gene classifier significantly improved the tests' ability to correctly identify both benign and malignant nodules, potentially resulting in fewer unnecessary surgeries.
In this histologically blinded, multicenter, cross-sectional cohort study, data was summarized from 109 nodules with indeterminate cytology and surgical outcomes of primary benign or malignant thyroid lesions established by local pathology expertise from 12 representative endocrinology centers across the United States. Following fine needle aspiration, combined use of mutation testing and ThyraMIR had an overall sensitivity of 89% and specificity of 85%. Importantly, researchers noted the improvements relative to current molecular classification methods are applicable regardless of the local prevalence of thyroid cancer.
"These promising results support the addition of microRNA testing to oncogene mutational analysis. This combined gene expression and genotyping approach is designed to more accurately diagnose and characterize thyroid nodules," said Thomas J. Giordano, M.D., Ph.D., Department of Pathology, University of Michigan, and a study author. "This can help clinicians to make the most appropriate management recommendations for their patients and hopefully avoid unnecessary surgeries on benign nodules."
Approximately 525,000 thyroid nodule fine needle aspiration (FNA) procedures are performed each year in the United States. Prevalence of thyroid cancer in the clinical setting is often not known and varies between institutions. Indeterminate cytology diagnoses are common and represent approximately 15% to 30% of cases. National Comprehensive Cancer Network (NCCN) and American Thyroid Association (ATA) guidelines currently recommend consideration of molecular testing on these indeterminate cases to help inform treatment decisions and to help avoid unnecessary surgery on benign nodules, which may occur in 70% to 80% of the cases.
"We are excited about these compelling data and that the use of this first and only microRNA gene expression classifier, combined with our thyroid oncogene mutational panel, can potentially further advance the diagnosis and treatment of thyroid lesions beyond currently available tests," said Nancy Lurker, CEO of PDI, Inc.
While studies support the value of mutational analysis, evidence continues to accumulate clearly showing that detection of ever-increasing numbers of uncommon mutations does not by itself provide diagnostic clarity, but in fact contributes to diminishing specificity for cancer detection.
Added Sydney Finkelstein, M.D., Chief Scientific Officer of Interpace Diagnostics:
A combined approach, fundamental to our testing, offers the most effective means to guide individual patient management and optimize healthcare resources.