Endocrine Abstracts

Aim: The aim of the study was to assess the effect of environmental and socio-economical factors on the increase in the incidence rate of thyroid cancer observed in Olsztyn and the Warmia and Mazury Region in the years 1994-2003.

Material and methods: In the group of patients registered in the standardized thyroid cancer register their place of residence, education level, place of parents descent, exposure to ionizing irradiation during the Chernobyl accident, iodine prophylaxis during irradiation, family history of thyroid diseases, thyroid diseases in childhood, lifestyle (smoking, drinking), nutritional habits, number of pregnancies and also contraception (used by women) were assesses based on specially designed questionnaire. Control group consist of healthy volunteers. They answered the same questionnaire.

Results: Among the patients who answered the questionnaire there were 261 women, average age 49.7 and 33 men, average age 51.4; 149 persons had elementary education, 220 patients were city inhabitants. 100% patients were exposed to ionizing irradiation during the Chernobyl accident, 31% received iodine prophylaxis during irradiation. Twenty seven patients (9%) had thyroid diseases in childhood and 96 patients (33%) had family history of thyroid diseases. 46% patients were on diet rich in milk and average in salt. The study population reported average cabbage and very low fish consumption.

Conclusions: l. Exposure to ionizing irradiation during the Chernobyl accident was the main risk factor in the increase in the incidence rate of thyroid cancer in study region. 2. The possible environmental factors were: the iodine deficiency caused by lack of iodine prophylaxis in the eighties and low fish consumption, diet rich in cruciferous vegetables. 3. Mothers of Bielarusia descent were the probably genetic risk factor.