More than 20 million Americans suffer from thyroid disease, but biopsies to determine if they have thyroid cancer are not definitive in at least a third of the cases. To err on the safe side, the thyroid gland or half of it is often removed, leaving some of the patients pill-dependent for the rest of their lives.

Hadassah physician-researchers have developed a method to increase biopsy accuracy, according to an article published in the journal Cancer Epidemiology Biomarkers & Prevention.

The method is based on mircroRNA testing. MicroRNAs are short RNA molecules which regulate many major cellular functions such as development, differentiation, growth, and metabolism.

Says first author Dr. Haggi Mazeh, head of General Surgery at Hadassah Mount Scopus:

“The thyroid gland is responsible for metabolism, temperature regulation, and more. Small nodules often form in the gland. A fine-needle biopsy may be needed to determine if the growth is benign or malignant. Of the thousands of biopsies performed every year in hospitals in Israel, about a third are inconclusive. In those cases we recommend repeating the procedure, expensive molecular examination or partial or complete gland resection.”

Co-author nephrologist Dr. Iddo Ben-Dov examined the microRNA of 274 thyroid specimens.

“MicroRNA are small molecules that affect tissue processes and they reflect changes such as the progress of a disease” Dr. Ben-Dov says.

The two investigators found clear differences between benign and malignant nodules. The doctors and researchers believe they can determine the nature of the growth to a 94-percent accuracy, which is far higher than other currently-available tests.