Late stage thyroid cancer patients with aggressive disease may benefit from a genetic test, but experts caution that use of this test in early stage patients is inappropriate because it is unlikely to lead to better outcomes. Testing for BRAF V600E-positive tumors should be reserved for patients older than 45 who have more advanced disease, according to an accompanying editorial in JAMA co-authored by two Perelman School of Medicine researchers at the University of Pennsylvania.
The most common form of thyroid cancer, papillary thyroid cancer (PTC), has an excellent prognosis when caught early, with five year survival rates of 98 percent. But 7 percent of people have an aggressive form of PTC that is more difficult to treat. A JAMA study looking at a test for a mutation in the BRAF gene (V600E) suggests that this gene mutation may be part of what makes the tumor so aggressive, suggesting that targeted treatments may be effective at inhibiting the BRAF function in PTC patients with advanced disease.
"While thyroid cancer is treatable and has a good prognosis in most cases, the aggressive cases of PTC can be unpredictable" said editorial co-author Anne Cappola, MD, ScM, associate professor of Medicine in Endocrinology in the Perelman School of Medicine at the University of Pennsylvania and a contributing editor at JAMA. "Genetic testing for these aggressive cases, but not for all cases, may help us match people's tumors with targeted treatments, when possible."
Co-author Susan Mandel, MD, MPH, director of the Penn Thyroid Center, professor of Medicine and Radiology, and incoming vice president of The Endocrine Society, noted that "patients with these aggressive forms of PTC may be eligible to participate in clinical trials testing drugs targeting BRAF and other targeted therapy trials."
The Penn-authored JAMA editorial is in reference to "Association between BRAF V600E mutation and mortality in patients with papillary thyroid cancer" by Xing et al, also in this week's genomics edition of JAMA.