Sex differences in thyroid cancer in Hanoi: Incidence trends and projections to 2045 from the Hanoi Cancer Registry.

Abstract

e18080 Background: Thyroid cancer epidemiology has shown distinct sex-related differences, with women historically having higher incidence rates than men in many regions. However, data from low- and middle-income countries (LMICs) such as Vietnam are limited. The objective of this study was to project sex differences in Thyroid cancer incidence over the next two decades. Methods: Thyroid cancer data (ICD-10 code C73) from 1990 to 2020 were obtained from the Hanoi Cancer Registry, alongside population data from the Vietnam General Statistics Office. Age-standardized rates (ASR) were calculated using the WHO World Standard Population (2000). Poisson regression models were performed to project future incidence for men and women. Future incidence was projected under the assumption that the estimated Annual Percentage Change (APC) from the most recently identified trend segment would remain constant through 2045. Results: Sex differences in disease burden were observed throughout the study period. In 1990, the ASR was similarly low for both sexes (men: 0.3; women: 0.8 per 100,000) (Table 1). Between 1990 and 2020, ASR among women increased to nearly seven times that observed in men (57.7 vs. 8.2 per 100,000 person-years). The highest risk among women was observed in those 49 years and younger. From 2020 to 2045, the gap between women and men is projected to remain unchanged (57.7 vs. 8.2 per 100,000). Conclusions: Thyroid cancer in Hanoi is predominantly a women's phenomenon, driven by a disproportionate surge in cases among young and middle-aged women. The incidence gap in thyroid cancer between women and men significantly widened from 1991 to 2020 and is projected to remain unchanged over the next two decades. However, the magnitude of their differences may be overestimated due to potential overdiagnosis among women. Public health strategies in Vietnam and other LMICs with similar population characteristics and thyroid cancer burden should prioritize care and treatment for women to narrow the gap. Two-decade projection of age-standardized thyroid cancer incidence rates per 100,000 person-years in Hanoi, Vietnam. Women Men Year Cases ASR (95% CI) Cases ASR (95% CI) 1990 9 0.8 (0.3-1.3) 4 0.3 (0.0-0.6) 2000 47 3.6 (2.6-4.7) 17 1.5 (0.8-2.2) 2010 352 10.4 (9.3-11.5) 80 2.6 (2.0-3.2) 2020 2,523 57.7 (55.4-59.9) 343 8.2 (7.3-9.1) 2025 2,822 57.6 (55.5-59.8) 385 8.2 (7.4-9.0) 2030 3,079 57.7 (55.6-59.7) 412 8.2 (7.4-9.0) 2035 3,309 57.7 (55.7-59.7) 435 8.2 (7.4-9.0) 2040 3,494 57.7 (55.7-59.6) 468 8.2 (7.5-9.0) 2045 3,617 57.7 (55.7-59.6) 497 8.2 (7.5-9.0)