The rising trend in papillary thyroid carcinoma: True increase or over diagnosis?

OBJECTIVES: To assess the changes in parameters of thyroid carcinoma, particularly papillary type, in the era of widespread use of sensitive diagnostic methods. We aim to investigate whether the increased frequency of thyroid cancer is true or resulted from over diagnosis. METHODS: We conducted a retrospective study of 313 cases of thyroid carcinoma diagnosed at Jordan: University Hospital and King Hussein Cancer Center from 2007-2015. Papillary carcinoma accounted for 290 (92.7%) of all cases. Cases were sub classified according to demographic features, histological type, size, stage, and other variables. For comparison of data, cases were subdivided into 2 study periods: Group I included patients diagnosed in the period 2007-2010, and Group II in the period 2011-2015. RESULTS: The frequency of thyroid carcinoma has increased across the study period. Papillary carcinoma was the major type accounting for this increase. Papillary micro carcinomas ≤1cm accounted for 34.8% of cases of PTC. Most cases (52.4%) of papillary thyroid carcinoma (PTC) were localized stage tumors. Group II of the study witnessed a more than doubled number of cases of PTC compared to group I, with increased frequency of tumors of all sizes as well as tumors of both localized and regional stages. CONCLUSIONS: Our observed trend cannot be totally explained by over diagnosis and increased diagnostic scrutiny. This increase could be of true nature and cannot be explained by single cause.