The Impact of Diagnostic Changes on the Rise in Thyroid Cancer Incidence: A Population-Based Study in Selected High-Resource Countries
- Study type
- Other
- Design
- Population-based study of incidence data (comparison of age-specific incidence rates across countries and time periods)
- Sample size
- Not stated in the abstract
- Source
- Thyroid · 2015
In plain words
In many high-income countries, the number of people diagnosed with thyroid cancer has gone up, but deaths from it have not. This study shows that a large part of this rise is probably because tools such as neck ultrasound find small tumours that might never have caused symptoms or harm. These findings do not mean thyroid cancer should not be taken seriously; rather, they show that aggressive treatment of every small tumour may not always be needed, and decisions should be made with your treating doctor.
Key results
Study population
Thyroid cancer incidence data from selected high-income countries: four Nordic countries, England and Scotland, France, Italy, the United States, Australia, Japan and the Republic of Korea. The Nordic countries before the 1970s were used as the reference.
Endpoints
Estimation of the proportion of thyroid cancer cases probably attributable to diagnostic changes (increased surveillance of the thyroid gland after the introduction of neck ultrasound in the 1980s); this proportion was estimated from the difference between observed rates and expected rates based on the Nordic countries.
Safety and side effects
Nothing notable is reported in the abstract (this was not an interventional study). The authors note that there is evidence of harm from close and extensive scrutiny of the thyroid.
Clinical significance and place in guidelines
This is a descriptive epidemiological study, and based on the abstract the authors conclude that the risk of overdiagnosis and overtreatment of thyroid cancer needs urgent attention. The article itself is not a clinical guideline; the status of current formal recommendations on screening and treatment should be checked separately in authoritative guidelines.
Limitations
These estimates are based on modelling and comparison with the historical reference pattern of the Nordic countries, not on direct measurement of overdiagnosis in individual patients. Further details on limitations are not given in the abstract and should be checked in the full text.
This summary was prepared by the editorial team from the published paper; the original paper is the final reference. Read the original abstract on PubMed.