Ecological studyindependent cross-checkabstract checked★ key study I-ORG-113 in-depth review

Thyroid cancer overdiagnosis in 63 countries

Evolving epidemiological patterns of thyroid cancer and estimates of overdiagnosis in 2013-17 in 63 countries worldwide: a population-based study.

Overview

Li M et al.. Lancet Diabetes Endocrinol 2024 · PMID 39389067 · DOI 10.1016/S2213-8587(24)00223-7

About three in four thyroid cancer diagnoses worldwide were estimated to be overdiagnosis, while deaths stayed low.

Does the study support the specific claim? Yes · Methodological quality: moderate

Study explained simply

What did the researchers want to find out?: Estimate thyroid cancer overdiagnosis worldwide
How was the study done?: Analysis of cancer registries and mortality data
How many people, animals or samples were studied?: 63 countries, 2.3 million cases
What was actually found?: 75.6% of cases attributed to overdiagnosis
How large was the observed effect?: n/a
What do the results mean in everyday life?: Many small thyroid cancers would never cause harm
What are the study's limitations?: Model-based
What does it say about Elawady's specific claim?: Supports the claim
Do the results apply to Germany and Europe?: Applies to Europe
What can explicitly not be concluded from this study?: Cannot tell which individual cancer is harmless

Authors: Li M et al.
Journal: Lancet Diabetes Endocrinol
Year: 2024
Identifier: PMID 39389067 DOI 10.1016/S2213-8587(24)00223-7
Verification: verified – PubMed efetch 2026-10-26; Crossref works API 2026-10-26
Retracted: no
Corrections: none
Extent checked: abstract only
Conflicts of interest and funding: Funded by Chinese and Italian public research bodies.

What are the features of the thyroid cancer diagnosis epidemic and the magnitude of overdiagnosis across countries?

Study design: Ecological study – Population-based registry study (IARC CI5 and WHO mortality data) with overdiagnosis estimation
Population: Population cancer registries in 63 countries
Country: Global (5 continents)
Period: Incidence 1980-2017; mortality 1980-2022
Sample size: 385 registries in 63 countries; 2,297,057 cases
Inclusion and exclusion criteria: CI5 registries

Exposure / intervention: Country, sex, age, period
Comparator: Between countries
Endpoints: Incidence, mortality, overdiagnosed cases
Statistical methods: Age-standardised rates; previously validated overdiagnosis estimation method

Results: Incidence rose 1980-2017 in most countries; highest in South Korea, Cyprus, Ecuador, China and Turkiye. Mortality differed between countries by only about 1.0-2.0 per 100,000. Overdiagnosis ranged from none (Uganda, Zimbabwe, Trinidad and Tobago) to more than 85% of cases in females in Cyprus, China, South Korea and Turkiye. Overall 1,736,133 (75.6%) of 2,297,057 cases attributed to overdiagnosis.
Absolute risks: 75.6% of thyroid cancer cases attributed to overdiagnosis.
Authors' conclusion: Overdiagnosis remains very large and is expanding rapidly to transitioning countries; a global public health challenge.

Proportion reproduced (75.6%).

Confirms that thyroid cancer overdiagnosis is a global phenomenon.

Lim 2017 shows some true increase.

Includes many European countries.

Strong support for the overdiagnosis claim.

Multidimensional assessment
Multidimensional assessment
Authenticity of the source	verified
Methodological quality	moderate
Risk of bias	not assessable
Precision of results	high
Directness	direct
Reproducibility	replicated
Consistency with the overall evidence	consistent
Regional transferability	high
Adequacy of the interpretation (by the archive)	not applicable

Egypt-specific estimates not reported in the abstract.