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.
Objetivo: Estudiar el patrón evolutivo de la incidencia de cáncer de tiroides. Métodos: Selección de casos incidentes de cáncer de tiroides en la Región de Murcia durante 1984-2008. Variables: edad, sexo, fecha de diagnóstico y morfología. Se calculan tasas de incidencia y porcentaje de cambio anual mediante modelos edad-periodo-cohorte bayesianos. Resultados: Se diagnosticaron 1414 casos, con un incremento de la tasa de 2,9 (1984-1988) a 7,3 (2004-2008) por 100.000. La incidencia en mujeres fue 3,5 veces mayor que en hombres, predominando el carcinoma papilar (67,7%). La tendencia fue creciente en ambos sexos, con aumentos más acentuados del papilar. En las mujeres, la incidencia aumenta con la edad, los años de calendario y en la cohorte de 1945-1963. El microcarcinoma papilar cuadriplica las tasas en mujeres. Conclusiones: El cáncer de tiroides, de ser un tumor raro se ha convertido en un tumor emergente. El papilar muestra los mayores cambios per se y por incluir paulatinamente un mayor porcentaje de microcarcinoma.