Many thyroid growths won't be called cancer any moreStaff writer ▼ | April 16, 2016
Fewer thyroid cancers are diagnosed in the United States now than in the recent past, perhaps signaling a change in physician practices, a new study says.
A change in practices Fewer thyroid cancers are diagnosed
The tripling of thyroid cancer cases over the past 30 years "used to be a mystery," said Dr. Luc Morris, lead author of a report published online April 14 in the journal JAMA Otolaryngology-Head & Neck Surgery.
But recently, many researchers attributed the rise largely to technological advances that allow doctors to identify and biopsy small, harmless nodules in the thyroid gland, said Morris. He is a surgical oncologist at Memorial Sloan Kettering Cancer Center in New York City.
"Up to 30 percent of healthy persons have small cancers in their thyroid glands, and nearly all of these would not go on to cause any problems for the person if the cancer were never discovered," he explained.
They've always been present, "like a huge submerged iceberg, but we are just getting better at finding them," Morris said.
That explains why the dramatic jump in thyroid cancer is best described as an "epidemic of diagnosis," not an epidemic of disease, he added.
For many patients, there would be no benefit - only potential harm - in diagnosing and surgically removing these growths, Morris said.
In the other report, published April 14 in JAMA Oncology, researchers announced that one type of thyroid cancer has been reclassified to reflect it is noninvasive and has a low risk of recurrence.
The name change applies to a tumor known as encapsulated follicular variant of papillary thyroid carcinoma, which accounts for 10 to 20 percent of all thyroid cancers diagnosed in Europe and North America, the researchers noted. Morris said this is among the tumor types that have led to overdiagnosis in the United States.
The new name keeps key features to aid pathologists in diagnosis, but leaves out "cancer," indicating that it need not be treated aggressively, the study authors said. ■