Thyroid Cancer Overdiagnosis: Understanding the Rising Rates and the Role of Ultrasonography
A recent study reveals a significant rate of overdiagnosis in papillary thyroid cancer (PTC) cases in the United States, raising questions about current diagnostic practices and the widespread use of thyroid ultrasonography. While advancements in detection have led to a 250% increase in thyroid cancer incidence since 1990, mortality rates have remained stable, suggesting that many detected cancers may never pose a threat to patients.
The Scale of Overdiagnosis
Researchers estimate that between 72% and 94% of PTC cases in the U.S. Were overdiagnosed between 1991 and 2019 1. Overdiagnosis is particularly prevalent among women, with rates ranging from 75% to 95%, compared to 63% to 90% in men. This means a substantial portion of individuals are being diagnosed with and treated for cancers that would likely never have caused symptoms or become life-threatening.
The Role of Ultrasonography
Thyroid ultrasonography has become a key tool in detecting thyroid nodules, both palpable and nonpalpable. Still, its increased use has also contributed to the identification of small, asymptomatic nodules that may not require intervention 4. Currently, there are no standardized guidelines on when to refer patients for ultrasonography, leading to potentially unnecessary testing.
Impact of Reducing Ultrasonography Use
The study modeled the potential impact of reducing thyroid ultrasonography for nonpalpable nodules. A 33% reduction in use could decrease PTC incidence by 17% in 2019, while a 67% reduction could lead to a 41% decrease, with minimal impact on overall mortality 1. This suggests that a more conservative approach to ultrasonography could significantly reduce the number of overdiagnosed cases without compromising patient outcomes.
Understanding Papillary Thyroid Carcinoma Variants
Papillary thyroid carcinoma (PTC) isn’t a single entity. various variants exist, some with different biological behaviors and clinical outcomes 2. Ultrasonography helps identify these variants based on characteristics like hypoechogenicity, spiculated or microlobulated margins, microcalcifications, and nonparallel orientation.
Study Limitations
Researchers acknowledge that the study’s findings may not be fully generalizable due to potential variations in ultrasonography practices across different institutions and regions. The study focused solely on mortality implications and did not assess the quality of life impacts associated with overdiagnosis and treatment.
The Future of Thyroid Cancer Diagnosis
While some degree of overdiagnosis may be unavoidable, researchers emphasize the opportunity to reduce unnecessary diagnoses without increasing mortality 1. Lowering the number of cancer diagnoses could alleviate psychological burdens and avoid unnecessary treatments, ultimately improving patient well-being without negatively affecting population health.
Key Takeaways
- A significant percentage of papillary thyroid cancer cases are overdiagnosed, particularly in women.
- Widespread use of thyroid ultrasonography contributes to the detection of non-threatening nodules.
- Reducing ultrasonography use could decrease incidence rates without impacting mortality.
- Further research is needed to refine diagnostic guidelines and improve patient care.
References
1 Francis DO et al. Overdiagnosis of papillary thyroid cancer. JAMA Netw Open. 2026;DOI:10.1001/jamanetworkopen.2025.59852.
2 Shin JH. Ultrasonographic imaging of papillary thyroid carcinoma variants. Ultrasonography. 2017;36(2):103–110.
3 Caldwell A. Thyroid Cancer Overdiagnosis Historically Up to 94% – EMJ.
4 Rethinking the Rise in Papillary Thyroid Cancer Diagnoses: The Overdiagnosis Issue. Bioengineer, February 24, 2026.