Thyroid Cancer Incidence and Trends in United States and Canadian Pediatric, Adolescent, and Young Adults
by
, , , , ,
May Z. Gao
1,
Tariq M. Omer
1,
Katherine M. Miller
2,
Matthew C. Simpson
3,
Aleksandr R. Bukatko
3,
Kalipa Gedion
4,
Eric Adjei Boakye
5,6,7,8,
Karen M. Kost
9,
James A. Dickinson
10,
Mark A. Varvares
11 and
Nosayaba Osazuwa-Peters
4,12,13,14,* 1
Duke University School of Medicine, Durham, NC 27710, USA
2
Department of Pediatric Otolaryngology, Head and Neck Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
3
Department of Otolaryngology–Head and Neck Surgery, Saint Louis University School of Medicine, St. Louis, MO 63104, USA
4
Duke Global Health Institute, Durham, NC 27710, USA
5
Department of Public Health Sciences, Henry Ford Health System, Detroit, MI 48202, USA
6
Department of Otolaryngology–Head and Neck Surgery, Henry Ford Health System, Detroit, MI 48202, USA
7
Henry Ford Health + Michigan State University Health Sciences, Detroit, MI 48202, USA
8
Department of Epidemiology and Biostatistics, Michigan State University College of Human Medicine, East Lansing, MI 48824, USA
9
Department of Otolaryngology–Head and Neck Surgery, McGill University, Montreal, QC H3A 0G4, Canada
10
Departments of Family Medicine and Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
11
Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
12
Department of Head and Neck Surgery & Communication Sciences, Duke University School of Medicine, Durham, NC 27710, USA
13
Department of Population Health Sciences, Duke University School of Medicine, Durham, NC 27710, USA
14
Cancer Risk, Detection, and Interception Program, Duke Cancer Institute, Durham, NC 27710, USA
*
Author to whom correspondence should be addressed.
Cancers 2025, 17(9), 1429; https://doi.org/10.3390/cancers17091429
Submission received: 6 February 2025
/
Revised: 17 April 2025
/
Accepted: 18 April 2025
/
Published: 24 April 2025
(This article belongs to the Special Issue Evolving Understanding of the Epidemiology of Thyroid Cancer)
Simple Summary
Thyroid cancer rates have been rising in North America, but most research has focused on adult patients. This study examines trends in thyroid cancer among pediatric, adolescents, and young adults (PAYA) in the United States and Canada. Using a comprehensive North American cancer registry, we found that thyroid cancer incidence increased by 137% from 1995 to 2014, with significant rises across all age groups. The increase was most pronounced in young White females and was highest for papillary thyroid cancer. Our findings suggest that overdiagnosis from thyroid ultrasound and incidental findings from other imaging are occurring, but other factors could be contributing to the rise. These results highlight the need for continued epidemiological monitoring and further research to understand the drivers of thyroid cancer incidence in young populations.
Abstract
Background/Objectives: Thyroid cancer incidence has risen in both the United States and Canada, despite differing healthcare systems. While overdiagnosis likely partly explains this trend in adults, its impact on younger populations is unclear. We used the North American Association of Central Cancer Registries, which included 133,808 thyroid cancer cases from the United States and Canada, to assess incidence trends among pediatric, adolescent, and young adult (PAYA) populations. Methods: Age-adjusted incidence rates (AAIR) per 100,000 person-years (PY) were compared using rate ratios (RR), stratified by sex, age, race/ethnicity (United States only), and histology. Joinpoint regression estimated annual percentage changes (APC) and average APCs (AAPC) in AAIRs. From 1995 to 2014, thyroid cancer incidence increased by 137%. Significant increases occurred across all age groups (0–14, 15–24, 25–34, 35–39 years). The rate increase was highest for papillary thyroid cancer (AAPC = 5.50, 95% CI 5.06, 5.94), and among individuals aged 35–39 years (AAPC = 5.99, 95% CI 4.84, 7.15). Of racial/ethnic groups in the United States, non-Hispanic White individuals had the highest AAIR (6.22 per 100,000 PY). Mortality has changed minimally. Conclusions: Over the past two decades, thyroid cancer incidence has increased in individuals under 40. While evidence suggests that overdiagnosis primarily accounts for this trend, other contributing factors cannot be ruled out. Further research and surveillance of the drivers of increased incidence are critical.
