(HealthDay)—From 2009 to 2016, the incidence of thyroid cancer reached a plateau and possibly started to decline, according to a research letter published in the Dec. 24/31 issue of the Journal of the American Medical Association.

Ann E. Powers, from the Icahn School of Medicine at Mount Sinai in New York City, and colleagues examined trends in age-adjusted thyroid cancer incidence from 1992 to 2016 in the Surveillance, Epidemiology, and End Results 13 registry.

The researchers found that from 1992 to 2009, there was an increase in thyroid cancer incidence in the United States from 5.7 to 13.8 per 100,000; the greatest annual percentage change (APC; 6.6 percent; 95 percent confidence interval [CI], 6.2 to 7.0 percent) was from 1998 to 2009. From 2009 to 2014, the rate of increase slowed significantly (incidence, 13.8 to 14.7 per 100,000; APC, 2.0 percent; 95 percent CI, 0.3 to 3.7 percent). The incidence of thyroid cancer has been stable since 2014 (14.7 to 14.1 per 100,000; APC, −2.4 percent; 95 percent CI, −7.5 to 3.1 percent). From 1992 to 2009, the incidence of subcentimeter thyroid cancers increased steadily from 1.2 to 4.7 per 100,000, with the greatest APC from 1996 to 2009 (9.1 percent; 95 percent CI, 8.4 to 9.8 percent). From 2009 to 2013, the trend stabilized (incidence, 4.7 to 5.3 per 100,000; APC, 2.9 percent; 95 percent CI, −2.5 to 8.6 percent) and then decreased from 2013 to 2016 (incidence, 5.3 to 4.7 per 100,000; APC, −3.7 percent; 95 percent CI, −8.7 to 1.7 percent).

"Although a true decline in the occurrence of thyroid cancer is a possible explanation for these changing trends, less intensive workup of thyroid nodules is more likely," the authors write.

One author and his laboratory received funding from pharmaceutical companies.

More information: Abstract/Full Text (subscription or payment may be required)

Journal information: Journal of the American Medical Association 

Copyright © 2019 HealthDay. All rights reserved.