Molecular Testing of Thyroid Nodules Offers Novel Diagnostic Tool for Thyroid Cancer

Newswise — Genetic testing of thyroid nodules offers a new tool to diagnose thyroid cancer, according to data to be presented on Oct. 3, 2008 at the 79th Annual Meeting of the American Thyroid Association (ATA) in Chicago, IL.

Using portions of freshly obtained fine needle aspiration (FNA) specimens from thyroid nodules, a team of researchers at University of Pittsburgh Medical Center screened 485 thyroid nodules for a panel of genetic mutations " BRAF V600E, NRAS codon 61, HRAS codon 61, KRAS codon 12/13 mutations and RET/PTC1, RET/PTC3 and PAX8/PPARg rearrangements " known to be linked to the development of many cancers, including thyroid cancer. The testing was following complete cytologic evaluation and included samples that were diagnosed by cytology as atypical/suspicious, suboptimal, or malignant.

Researchers found 59 nodules that tested positive for one of these mutations. Of the 50 patients with detected mutations who have since undergone surgery, 96% were diagnosed with malignant tumors. Researchers determined that all nodules with BRAF and RET/PTC mutations were papillary carcinomas and 90% of RAS-positive nodules were malignant.

"Testing for genetic mutation in thyroid FNA sample is a novel diagnostic tool to integrate into clinical practice," said principal investigator Dr. Yuri Nikiforov. "Moreover, in addition to the expected high diagnostic value of BRAF and RET/PTC mutations, we found that RAS mutations also have a high positive predictive value for malignancy and are very helpful for detecting cancer in thyroid nodules."

About the American Thyroid Association (ATA)The American Thyroid Association (ATA) is the lead organization in promoting thyroid health and understanding thyroid biology. The ATA values scientific inquiry, clinical excellence, public service, education, collaboration, and collegiality.

A non-profit medical society founded in 1923, the ATA fulfills its mission through supporting excellence and innovation in research, clinical care, education, and public health. ATA members are physicians and scientists who work to enhance the understanding of thyroid physiology and pathophysiology, improve the diagnosis and treatment of thyroid diseases, and promote the education of physicians, patients, and the public about thyroid disorders.

Thyroid diseases are among the most common disorders of the endocrine system, affecting almost 13 million Americans alone. The ATA has extensive online information for patients on thyroid disease (in English and Spanish) serving the clinician as a resource for patients and the public who look for reliable information on the internet.

To learn more about the ATA, visit: http://www.thyroid.org.

Distribution of information regarding research presented at ATA meetings is thought to be of interest to the public, however, this does not imply official endorsement by the ATA.