LYON, France, Aug. 23 (UPI) -- Increasingly, researchers and doctors are expressing concern about over-treatment of diseases and the possibility patients are being harmed in the interest of avoiding low-risk adverse health conditions, with thyroid cancer being the latest.
Researchers at the World Health Organization say the huge explosion of thyroid cancer diagnoses and treatment is the product of new scanning techniques, but tumors found in most patients during the last two decades do not pose a risk to health.
The WHO's International Agency for Research on Cancer found new scanning technologies adopted since the early 1980s such as neck ultrasonography, computed tomography scanning and magnetic resonance imaging have found small tumors and nodules on patients' thyroid glands.
Even when doctors detect what researchers call indolent, non-lethal disease that would be better handled with a wait-and-see approach, they often jump to put patients through difficult, challenging treatment regimens.
Treatment often includes the removal of thyroid glands, requiring patients to take thyroid hormones for the rest of their lives -- as a result of treatment they most likely did not need.
"The majority of the overdiagnosed thyroid cancer cases undergo total thyroidectomy and frequently other harmful treatments, like neck lymph node dissection and radiotherapy, without proven benefits in terms of improved survival," Dr. Silvia Franceschi, a researcher in the IARC's infections and cancer epidemiology group, said in a press release.
According to the study, published in the New England Journal of Medicine, most developed countries the IARC looked at as part of its Cancer Incidence in Five Continents study have an overwhelming rate of overdiagnosis of the disease.
The researchers found that between 70 percent and 80 percent of women diagnosed from 2003 to 2007 with thyroid cancer in Australia, France, Italy and the United States should not have been diagnosed with the disease, with the same found for about 50 percent of women in Japan, the Nordic countries, England and Scotland.
For men, the numbers are similar: About 70 percent of cases in France, Italy and the Republic of Korea were overdiagnoses, as were 45 percent of cases in the United States and Australia.
The agency says more research is necessary on the best way to approach the theoretical epidemic of thyroid cancer and how to prevent harming patients with treatment they do not need.
"More than half a million people are estimated to have been overdiagnosed with thyroid cancer in the 12 countries studied," said Dr. Christopher Wild, director of the IARC. "The drastic increase in overdiagnosis and overtreatment of thyroid cancer is already a serious public health concern in many high-income countries, with worrying signs of the same trend in low- and middle-income countries."