Queensland data has found overdiagnosis has not been solely to blame for a sharp increase of thyroid cancer cases in Queensland since the early 1980s.
Cases of thyroid cancer increased by 5.5 per cent per year for Queensland men and 6.1 per cent per year for Queensland women between 1982 and 2008, a significant rise.
The data also found a threefold difference in thyroid cancer incidence between Queensland men and women – similar to patterns in other developed countries.
Cancer Council Queensland spokesperson Katie Clift said more research was needed to determine the cause of the sharp increase.
“Rates of thyroid cancer have increased significantly in many countries including Australia, and the reasons why are still largely unknown,” Ms Clift said.
“Previous research suggested the increase was due to overdiagnosis – tumours that would never have caused symptoms or death, but were diagnosed due to the use of sensitive diagnostic tests.
“Our study found an increase in early stage cancers, but also a significant rise in the diagnosis of advanced thyroid cancers during the time period.
“While overdiagnosis may account for some of the increase, the patterns we observed suggest other factors may be playing a role in the rise of thyroid cancer cases.
“Potentially, a range of factors may be involved, including obesity and environmental factors. More research into the reasons for these rapid increases is particularly important moving forward.”
The research found Queensland women aged 40-49 were most likely to be diagnosed with thyroid cancer over the time period, followed by women aged 30-39, and women aged 50-59.
In 2007-08, 679 Queensland women were diagnosed with thyroid cancer, compared to just 230 Queensland men.
Cancer Council Queensland urged men and women to be aware of the symptoms of thyroid cancer, and to see their GP with any questions or concerns.
“Thyroid cancer tends to develop slowly, without many obvious symptoms,” Ms Clift said.
“One of the more common symptoms is a painless lump in the neck or throat that may gradually get bigger. People may also experience hoarseness and difficulty swallowing or breathing.”
Thyroid cancer occurs when the cells of the thyroid gland (a gland in front of the neck, below the voice box) grow and divide in a disorderly way.
The research examined 5083 thyroid cancer cases diagnosed in Queensland between 1982 and 2008.
The research was conducted by QIMR Berghofer Medical Research Institute in collaboration with The University of Queensland, Cancer Council and the Royal Brisbane and Women’s Hospital.
More than 560 Queenslanders are diagnosed with thyroid cancer each year, and about 15 die from the disease.
More information about Cancer Council Queensland is available via 13 11 20 or cancerqld.org.au.