"Zealous" imaging is resulting in the overdiagnosis and overtreatment of low-risk thyroid cancer, according to a report published online Aug. 27, in the journal BMJ.
According to the authors, led by Juan Brito, M.D., of the Mayo Clinic in Rochester, Minn., the incidence of thyroid cancer has skyrocketed over the last 30 years, tripling in number from 3.6 cases per 100,000 persons in 1973 to 11.6 cases per 100,000 in 2009. But, 90 percent of these are small low-risk papillary thyroid cancers.
The expanding gap between the incidence of thyroid cancer and a stable death rate from papillary thyroid cancer--0.5 per 100,000 in both 1979 and 2009--suggest that thyroid cancer is being overdiagnosed and overtreated.
There can be significant consequences to overtreatment. The number of thyroidectomies in the U.S. has increased by 60 percent over the last 10 years; the procedure is expensive and carries risks such as laryngeal nerve injury.
According to the authors these low-risk cancers are being detected because of the easy availability of imaging devices such as portable ultrasound.
"These indolent thyroid cancers are being discovered because we have the technology to see nodules as small as 2 mm," Brito told Medscape Medical News. "The fact that we can do biopsies at the bedside is triggering overdiagnosis and overtreatment of papillary thyroid cancer."
Brito added that physicians should discuss with patients whether surgery is actually warranted, "putting the patient in the center of the decision-making process. If you discuss the benefits and harms," he said, "sometimes they might not choose surgery; they might be willing to have active surveillance.
Brito and his colleagues called for further research to identify the appropriate care for patients with low-risk thyroid cancer, and suggested changing the nomenclature surrounding the diagnosis in such a way as to emphasize the favorable prognosis for thyroid cancers.