A dramatic rise in thyroid cancer has resulted from overdiagnosis and treatment of tumors too small to ever cause harm, according to a study that found cases nearly tripled since 1975.
The study is the latest to question whether all cancers need aggressive treatment. Other research has suggested that certain cancers of the prostate, breast and lung as well as thyroid grow so slowly that they will never become deadly, and that overzealous screening leads to overtreatment.
The thyroid is a hormone-releasing gland in the neck that helps regulate the body’s metabolism. Thyroid cancer treatment often includes surgery to remove the butterfly-shaped gland, followed by lifelong daily hormone pills.
Thyroid removal is done for 85 percent of all people diagnosed despite guidelines that say less aggressive surgery is reasonable for lower-risk thyroid tumors, the study authors said.
“Our old strategy of looking as hard as possible to find cancer has some real side effects,” said Dr. Gilbert Welch, co-author of the thyroid study and a professor of medicine at the Dartmouth Institute for Health Policy and Clinical Practice.
Welch said patients “can no longer assume” that labeling a disease as cancer means treatment is necessary. “It’s a challenging rethinking,” he added.
Welch and Dartmouth colleague Dr. Louise Davies analyzed government data from 1975 to 2009 and found thyroid cancers jumped from 5 cases per 100,000 people to 14 per 100,000. Most of that increase was in papillary thyroid cancers, the most common and least deadly kind; those cases jumped from about three cases per 100,000 to more than 12 per 100,000.
The results suggest there is “an ongoing epidemic of thyroid cancer” nationwide, they said. The study was published online Thursday in JAMA Otolaryngology.