Continued rise in the incidence of thyroid cancer in Iran: true increase or overdiagnosis

From 2014 to 2018, a total of 27,530 cases of TC were recorded. Among these cases, 21,932 (79.7%) were female, and 5,598 (20.3%) were male. The age-standardized incidence rate (ASR) of TC was 6.17 (95% confidence interval [CI]: 6.09-6.25) per 100,000 person-years, showing an upward trend from 4.61 (95% CI: 4.45-4.77) per 100,000 population in 2014 to 8.17 (95% CI: 7.97-8.37) in 2018. The ASR of TC in women was nearly 3.7 times higher than that in men (9.79 vs. 2.59 per 100,000 person-years). The ASR of TC was highest in younger age groups among women (40-50 years) compared to men, who had higher rates in older age groups (65-75 years). Papillary thyroid carcinoma (PTC), including its follicular variant, was the predominant histological type of TC in the Iranian population, accounting for 82.19% (n = 22,627) of cases, followed by follicular thyroid carcinoma (FTC) (n = 859; 3.12%).