Thyroid cancer: are doctors over-diagnosing?

Thyroid cancer cases have been overdiagnosed and overtreated in recent years, a new study suggests.

There has been a surge in the amount of cases, with the number of diagnoses almost tripling since 1975 from 4.9 to 14.3 cases per 100,000 people. And most of these instances are from the more common but less aggressive papillary thyroid cancer form of the disease - from 3.4 to 12.5 per 100,000 people.

One source of overdiagnosis, according to researchers, is people having their neck imaged in order to look for artery blockages or other potential issues, and accidentally happening upon thyroid nodules.

"This means that a lot of people are having their thyroids removed for a cancer that was never going to bother them," lead researcher Dr. H. Gilbert Welch, a professor of medicine at the Dartmouth Institute for Health Policy and Clinical Practice, told HealthDay.

Dr. David Cooper, a professor of medicine and radiology at Johns Hopkins University School of Medicine, thinks surgery is ultimately seen as the only treatment option.

"Once a thyroid abnormality is found, it is hard to ignore it in the current medical environment, and patients often end up on an unstoppable juggernaut, leading to invasive procedures such as thyroid biopsy and ultimately to surgery," Cooper said.

The research team used federal government data to study patients with thyroid cancer from 1975 to 2012, and found that women were most affected. The number of cases increased from 6.5 to 21.4 per 100,000 women - nearly four times more than for men, which rose from 3.1 to 6.9 cases per 100,000 men.

Welch remarked, however, that the approach to treating cancer is changing.

"Medicine is in the midst of a course correction," he said. "We've believed for years that the best strategy for cancer was to find as much as we could, but we are realizing that the population harbors a lot of early cancer, and we have to make sure we don't create more problems than we solve by looking for them."