Australian researchers say too many patients are undergoing thyroid cancer surgery unnecessarily.

Too many patients diagnosed with thyroid cancer are undergoing "unnecessary" surgery, according to new research.

A study led by researchers at the Australian National University (ANU) has found there has been a three-fold increase in the number of differentiated thyroid cases.

This is due to overly meticulous examinations, which has created an artificial epidemic that is costing billions of dollars each year in medical costs, says Associate Professor Suhail Doi.

He says when the thyroid cancer is caught very early there is no need to intervene surgically because the cancer is still benign.

People with this type of thyroid cancer can live until normal life expectancy and usually die from other causes.

"Only some of these cases require treatment if and when the condition progresses to clinical forms of cancer."

According to the study, published in the Journal of Clinical Oncology, the number of patients diagnosed with differentiated thyroid cancer in Australia between 1982 and 2012 increased by three times in women and two times in men.

It's estimated around 2500 new cases will be diagnosed in Australia this year and the medical costs for differentiated thyroid cancer will be about $390 million in 2019.

With thyroid cancer surgery having substantial consequences, including a lifetime spent on thyroid-replacement therapy, it's hoped the research will improve a patient's quality of life and reduce "avoidable burden on health systems", said Dr Doi.