Changing patterns in thyroid cancer incidence and mortality in the Slovak Republic by histological type and age

Thyroid cancer (TC) is the most common malignant disease of the endocrine system; however, in the Slovak Republic (SR), time trends of incidence and mortality according to histological type and age of patients have never been reported.

Long-term (1968-2007) trends from the National Cancer Registry data of overall, histology and age-specific incidence and mortality in the SR have been calculated using join-point regression and other descriptive characteristics.

Age-standardized overall incidence rates increased significantly in females by an estimated annual percentage change (APC) of 3.6 %, and in males by 2.2 %. Overall mortality decreased by APC -2.1 % in females and -0.9 % in males. The mean ages of female and male TC patients at the time of diagnosis significantly decreased; ages at the time of death significantly increased. The incidence of papillary carcinoma rose significantly in females by 8.9 %, compared with 6.1 % in males; follicular carcinoma in males and females was stable. Medullary carcinoma was stable in females; in males, it rose by 5.2 %. Poorly differentiated TC was stable in females; undifferentiated/anaplastic carcinomas decreased in both sexes.

The incidence of TC, especially of selected histological types, is dramatically rising in the SR in both genders, while mortality is decreasing. Patients diagnosed in recent years are younger and died at a greater age than those reported in older national data. These trends seem to be affected by more intensive diagnosis in the most recent years.