Trends in Prevalence of Thyroid Cancer Over Three Decades: A Retrospective Cohort Study of 17,526 Surgical Patients

Abstract Introduction Thyroid cancer (TC) incidence has been increasing in recent years. The aim of this study was to investigate our institution‐based estimates of operative volumes for TC over the last three decades. Materials and methods This was a retrospective cohort study of patients undergoing thyroid surgery at our institution. Patient characteristics were reviewed in three subgroups: Group I (treated in 1981–1986), Group II (treated in 1987–2002), and Group III (treated in 2003–2012). Results TC was diagnosed in 1578/17,526 (9.0 %) thyroid operations. Incidence of TC increased from 3.7 % in Group I to 10.4 % in Group III ( p < 0.001). Incidence of papillary TC increased form 40.6 % in Group I to 81.3 % in Group III ( p < 0.001). In the latter group, 23.5 % of all papillary TCs were diagnosed in patients with Hashimoto’s disease. Meanwhile, incidence of anaplastic TC decreased from 16.2 % in Group I to 2.1 % in Group III patients ( p < 0.001). pT1 tumors were diagnosed in 8.1 % Group I and 54.8 % Group III ( p < 0.001), whereas pT4 tumors were identified in 40.5 % Group I, 2.4 % Group II, and 0.84 % Group III subjects ( p < 0.001). pT3 tumors were found in 51.6 % Group I, whereas multifocal papillary TCs were found in 15.7 % Group III patients, the latter with a higher prevalence of pN1 stage ( p < 0.001). Conclusions The following trends in surgical volume for TC were identified throughout the study period: a fivefold increase of thyroid operations for TC, a threefold increase in incidence of papillary TC, and an eightfold decrease in incidence of anaplastic TC. It is of interest that a significant increase in incidence of multifocal papillary TC in young female patients with Hashimoto’s disease was found over time.