[Trend pattern of the incidence of thyroid cancer in Murcia Region (Spain) from 1984 to 2008]

Abstract

Objective: To study the trend pattern of the incidence of thyroid cancer.

Methods: We selected incident cases of thyroid cancer occurring in the Region of Murcia (Spain) in 1984-2008. The variables gathered were age, sex, date of diagnosis, and morphology. We calculated incidence rates and the annual percentage of change using Bayesian age-period-cohort models.

Results: During the study period, 1414 cases were diagnosed, representing an increase in adjusted rates from 2.9/100000 in 1984-1988 to 7.3 in 2004-2008. The incidence was 3.5 times higher in women than in men and the most frequent morphology was papillary carcinoma (67.7%). An increasing trend was found in both genders; these increments were more pronounced in papillary carcinoma. In women, the incidence increased with age, calendar year, and in those born in 1945-1963. The incidence of papillary microcarcinoma increased four-fold in women.

Conclusions: Thyroid cancer used to be a rare cancer but has become an emerging tumor. The greatest changes were found in papillary thyroid cancer, including a gradual increase in the proportion of microcarcinoma.

Keywords: Cohort effect; Cáncer de tiroides; Efecto cohorte; Histology; Histología; Incidence; Incidencia; Tendencias; Thyroid neoplasm; Trends.