Endocrine Abstracts

Background: The Olsztyn region, in the north-east of Poland, is mainly a rural area with the population of 0.77 mln. After the Chernobyl breakdown the region was classified as one of the most heavily radioactively contaminated areas of Poland. It was also characterized by mild severity of iodine deficiency and endemic goiter before iodine prophylaxis introduction in 1996/7.

Aim of the study: To evaluate the incidence rate (IR), current trend and histotype of thyroid cancer in relation to sex and age of patients.

Methods: All the diagnosed cases of thyroid cancer were collected according to the following entry criteria: residence in the study area, histopathological verification according to ICD-10. The incidence rate was calculated as the number of newly diagnosed thyroid cancer cases per 100 000 inhabitants annually. The National Statistical Office was the source of all the demographic data (population, residence, age group).

Results: In the study period 566 newly diagnosed cases (476 women average age 48.9 and 90 men average age 50.9) of malignant neoplasms of the thyroid gland were registered. In the age group 0–18 there were 10 patients (6 girls, 4 boys). A significant increase in the incidence rate (IR) of thyroid cancer was observed in the last twelve years from 1.7 in 1993 to 8.37/100 000 for all patients and from 3.1 to 14.8/100 000 in women only. The dominating type was papillary carcinoma −75.9%.

Conclusions: 1. Between 1993 and 2004 an increase in the incidence rate of thyroid cancer was observed in Olsztyn region. 2. Papillary thyroid carcinoma was the most common cancer type (75.9%).