The panel of 19 miRNAs identified using the following sequence generation can classify uncertain thyroid nodules benign and malignant samples.
The study is published in the journal Cancer Epidemiology, Biomarkers & Prevention, the journal of the American Association for Cancer Research.
"Thyroid nodules are extremely common and sometimes contain cancer cells," - explained Mazekh. "Patients who undergo assessment of thyroid nodules are often produced mixed results, and currently there are limited opportunities for further control, which represents a clinically unmet need."
Patients with suspicious nodes thyroid often obtained thin iglostruynuyu biopsies (FNAB) to facilitate diagnosis of malignancy. However, approximately 30 percent of patients who undergo this procedure are faced with uncertain results, said Mazekh. He added that the modern methods of molecular testing for the analysis of indeterminate thyroid nodes often are expensive and do not have the desired sensitivity and specificity.
Previous work carried out Mazeh and others have identified several miRNAs with altered expression in thyroid cancer. However, the specific role of these miRNAs play in the development of cancer and its diagnostic utility, has not yet been clarified, explained Ben-Dov.
MicroRNAs are short non-coding RNAs that regulate the function of cells and play a role in cancer development.
For the development of microRNA panel Mazekh and his colleagues analyzed biopsies from 102 patients who underwent total thyroidectomy. Once the thyroid is removed, of FNAB was performed on thyroid nodes, which led to 274 biopsies. Samples were classified as benign (71 percent) or malignant (29 percent) based on the pathological diagnosis, and the RNA was isolated from biopsies and analyzed via deep sequencing to identify the types and quantity of miRNA present.
After sequencing Mazekh and his colleagues found 279 miRNAs in thyroid nodes; 19 of them had significant differential expression between malignant and benign samples and were selected for a diagnostic panel.
"It was noted that many of the miRNAs identified in our group, contribute to the spread of proliferation, migration and invasion of the thyroid gland, while some inhibit the proliferation of thyroid cancer cells to induce apoptosis", - said Ben-Dov.
Using the diagnostic miRNA panel Mazekh and colleagues analyzed 66 biopsies from 35 patients with undefined disease and found that 22 patients were malignant thyroid nodules, and 13 patients were benign thyroid nodules. Of the patients with malignant tumors, 15 patients were diagnosed with papillary thyroid cancer, and seven patients showed thyroid follicular cancer.
Sensitivity, specificity, negative predictive value, positive predictive value and overall diagnostic accuracy of the panel as compared to the gold standard pathology were 91%, 100%, 87%, 100% and 94% respectively.
"Our results provide an updated list of candidate miRNAs for diagnostic use and support the view that the quantification of microRNA is a promising form of molecular pathology" - Mazekh said. "Further studies are needed to verify the clinical benefit of this approach for potential patients."