Endocrine Abstracts

Introduction: Thyroid cancer is the most frequent malignant endocrine neoplasia. Its incidence has significantly risen worldwide in the last decades.

Objective: To estimate the incidence of thyroid cancer in Valladolid’s east area population, Spain, over the period 2002–2016.

Methods: A retrospective descriptive research was performed in the Clinical Universitary Hospital of Valladolid (HCUVa). Clinical data was obtained from Anatomical Pathology Registry of HCUVa from 2002 to 2016. At diagnosis, the age, sex, histological features, size and stage of the thyroid tumor were analyzed. Incidence diagnosed rates were calculated adjusted to reference European Population by sex and age in three-year periods.

Results: 398 patients were diagnosed of Differentiated Thyroid Cancer from 2002 to 2016; 78.6% were women with a mean age of 52.44 years (DS 15.20). The overall incidence of thyroid cancer increased over the last 15 years, from 5.2 to 25.7 per 10⁵ population/year in women and from 2.3 to 8.8 per 10⁵ population/year in men (P<0.0001). Incidence rates were significantly higher in males compared to females. Mean age at diagnosis increased from 45.54 years (DS 15.94) to 54.53 years (DS 15.61) (P<0.01). There were no statistical differences in tumor size at diagnosis. However, a size increment trend in papillary macrocarcinomas from 1.8 cm (DS 0.77) to 2.49 cm (DS 1.54) – ns – was observed. Gender and papillary and follicular carcinoma rates kept stable over the period (19.2–21.4%) and (92.3–97.1% and 7.7–3.3%), respectively -ns-. An increase in micropapillary thyroid cancer (<1 cm) from 29.4% to 52.1% -ns- was observed throughout the period. Finally, the distribution of papillary carcinomas over the whole period was: 51.21% of classic variant of papillary thyroid cancer, 42.98% of follicular variant and 5.8% of aggressive variant. An increment of follicular variant and aggressive papillary carcinoma from 29.2% to 50.7% and from 4.2% to 8.2% was observed from 2002 to 2016, respectively (P<0.05).

Conclusions: During the period studied, the incidence of thyroid cancer increased in Valladolid in both sexes. The increase in micropapillary thyroid cancer diagnose was mainly responsible for this rising trend. These results suggest an increase of thyroid cancer in the diagnosis due to changes in clinical practice and the extensive introduction of new diagnostic techniques, such as neck ultrasonography.