Research reveals “artificial” thyroid cancer epidemic
Research led by a faculty member at the College of Medicine (CMED) finds doctors globally are over diagnosing patients with the most common thyroid cancer, creating an artificial epidemic that costs billions of dollars in unnecessary medical care costs annually.
CMED associate professor of Clinical Epidemiology Dr Suhail Doi who is the principle investigator in the study said diagnoses of differentiated thyroid cancer globally had increased three-fold internationally during the past 25 years -- up to 15-fold in countries with widespread thyroid screening programs -- despite no change to the disease’s low death rate.
“Differentiated thyroid cancer mainly involves papillary and follicular tumors that don’t usually progress to clinical forms of cancer, but overly meticulous examinations are detecting the condition in the early stages and resulting in unnecessary surgeries,” said Dr Doi, who is also a clinical epidemiologist at the Australian National University (ANU) Research School of Population Health and a specialist in endocrinology.
“Active monitoring rather than intervention is appropriate in many cases, similar to how doctors treat prostate cancer today,” Dr Doi said.
About 2,500 new cases will be diagnosed in Australia this year.
Thyroid cancer surgery has substantial consequences for patients -- most must receive lifelong thyroid-replacement therapy, and some have complications from the procedure including damage to nerves and surrounding glands.
Dr Doi said the research findings, published in the Journal of Clinical Oncology (JCO), would inform clinical guidelines around the world on appropriate treatment for differentiated thyroid cancer, and also help to educate the general public about the condition.
“People with this type of thyroid cancer can sometimes live until normal life expectancy with the condition and usually die from other causes, so there is no point diagnosing and intervening if the cancer is acting in a benign way and not causing any problems,” Dr Doi said.
He added: “Only some of these cases require treatment if and when the condition progresses to clinical forms of cancer.”
In 2019, the projected medical care costs for differentiated thyroid cancer in United States is estimated to be more than US$3 billion.
“The medical costs for differentiated thyroid cancer in Australia could be about $US300 million in 2019, if we extrapolate from the US projection,” he said.
Dr Doi and his colleagues analyzed international autopsy data, including from regions that had high and low instances of differentiated thyroid cancer, from the 1960s to 2007.
They were able to demonstrate that incidental and clinically inapparent differentiated thyroid cancer has remained unchanged over six decades, confirming for the first time that the epidemic has been driven by increasing detections of cancer.
Dr Doi said: “Ultimately, this research will help improve thyroid cancer patients’ quality of life and reduce avoidable burden on health systems.”
Other co-authors of this study are ANU PhD student Luis Furuya-Kanamori, Dr Katy Bell from University of Sydney, and Justin Clark and Professor Paul Glasziou at Bond University.