New research published today in the Journal of the American Medical Association has concluded that even thyroid nodules that grow in size are unlikely to become cancerous.
The research team followed 992 patients in Italy with benign thyroid nodules for five years, beginning in 2006.
"The results of our study suggest that most benign nodules exhibit no significant size changes over time, and some actually decrease in size,” said Sebastiano Filetti, professor of internal medicine at the University of Rome Sapienza, Italy, principal investigator of the study, and American Thyroid Association (ATA) member, in an interview with Healthline. “Only a subgroup of nodules can be expected to grow, about 15 percent in our series.”
The research also suggests that growing nodules do not, in fact, require more frequent screenings.
“Nodule growth is regarded as a possible predictor of malignancy,” said Filetti. “This was not confirmed in our study. If a nodule is benign it is very likely that it will remain benign during follow-up, even if it grows.”
While screening nodules is crucial for early cancer detection, the ATA reports that more than 90 percent of nodules remain noncancerous. Nodule growth was thought to predict which nodules would develop cancer.
New Follow-Up Standards
“Filetti's data confirm that benign nodules can be safely managed with a conservative approach of follow-up,” said Erik K. Alexander, chief of the thyroid section at the Brigham and Women’s Hospital and associate professor of medicine at Harvard Medical School, in an interview with Healthline. “The ATA is in the final process of publishing the updated thyroid nodule and cancer clinical guidelines, which will recommend conservative follow-up of benign, asymptomatic thyroid nodules.”
One such change, Filetti hopes, will be to extend the screening interval for the condition.
“Current guidelines call for fairly close follow-up of thyroid nodules,” he said. “In particular, they suggest repeating thyroid ultrasonography every three to five years. Our study provides documented evidence that it is safe to increase the follow-up interval to five years.”
Reduced follow-up frequency not only avoids wasting valuable medical resources but also saves patients time and stress. Alexander emphasizes the importance of keeping thyroid nodule risk in perspective.
“Thyroid nodules are very common,” he said. “While evaluation is important, a balanced and safe approach can help identify cancerous nodules that may pose a risk ahead, while allowing the majority of patients with a benign [nodule] to live a safe and healthy life ahead.”
Thyroid Cancer Affects Thousands of People
Although thyroid cancer has a low death rate compared to most other cancers, it still has far-reaching effects.
An estimated 62,450 people in the United States will develop thyroid cancer and 1,950 people will die from it this year, according to the American Cancer Society (ACS).
The key to successful recovery from thyroid cancer lies in early detection.
The ACS reports that nearly 100 percent of people with stage 1 or 2 thyroid cancer survive at least five years, a number that drops to around 50 percent by stage 4. By screening for thyroid nodules, doctors can catch cancer at its earliest stages.
“An annual physical examination of the thyroid is recommended in asymptomatic individuals as well as examination in anyone with symptoms that could suggest thyroid disease,” said Alexander. “Most nodules are asymptomatic, hence the routine examination of the neck and thyroid structures is very important for detection of nodules and potential thyroid cancer.”
Currently, the ATA recommends that people with benign thyroid nodules get checked every six to 18 months. If the nodules do not grow in size, this interval can be extended to three to five years.