"Most think that the largest component of the reason is the increased use of imaging. We're imaging more and more, and we're picking up more potentially indolent disease."
Thyroid cancer is largely a young person's disease, and the average age of those diagnosed is currently 49. However, 16% of the new patients diagnosed are between the ages of 20 and 34 while another 20% are between 35 and 44.
Use of radioactive iodine, while mostly safe, can involve side effects and complications, such as adverse impacts on quality of life, damage to local tissue such as salivary glands, and additional adverse effects. In rare cases, radiation can result in secondary cancers such as leukemia.
Haymart says a further review of the study's results will reveal regional trends in use of radioactive iodine in low-risk patients, so the reasons for more aggressive care may become a bit clearer.
"There was a wide between-hospital variation in radioactive iodine use, and much of the variance was attributable to unexplained hospital characteristics," the researchers wrote. An upcoming report will further analyze use of radioactive iodine in various groups of patients by hospital.
In an accompanying editorial, however, Edward Livingston, MD, and Robert McNutt, MD, of the division of gastrointestinal and endocrine surgery at the University of Texas Southwestern Medical Center in Dallas questioned Haymart's findings.
"The authors conclude that the substantial between-hospital variation in RAI use suggests clinical uncertainty and perhaps inappropriate use of radioactive iodine in thyroid cancer management," they wrote.