No Need for Genetic Testing for Most Thyroid Cancers

In the majority of patients with papillary thyroid cancer, the most common form of thyroid cancer, there is no need for genetic testing. However, there might be a role for such testing in the 7% of patients who present with an aggressive form of the disease.

This finding comes from a study published in the April 10 issue of JAMA that explores the association between the BRAF V600E mutation and mortality in patients with papillary thyroid cancer.

“Genetic testing for these aggressive cases, but not for all cases, may help us match people’s tumors with targeted treatments, when possible,” said Anne Cappola, MD, ScM, associate professor of medicine at the Perelman School of Medicine, University of Pennsylvania in Philadelphia, who cowrote anaccompanying editorial.

Papillary thyroid cancer accounts for 85% to 90% of all thyroid cancers, and has an excellent prognosis; 5-year survival rates are 98%, the editorialists explain. Usual treatment is surgery and/or radioiodine ablation.

However, for the 7% of patients with an aggressive form of the disease, the natural history is unpredictable. In these patients, there are few therapeutic options, they add.

How to identify the subset of patients who need aggressive treatment to reduce mortality is a “major clinical challenge,” write the researchers, headed by Mingzhao Xing, MD, PhD, from the division of endocrinology and metabolism at Johns Hopkins University School of Medicine in Baltimore, Maryland.

This represents a widely controversial issue in thyroid cancer medicine.Dr. Mingzhao Xing

“This represents a widely controversial issue in thyroid cancer medicine, particularly because of the low overall mortality of this cancer,” Dr. Xing and colleagues note.