Association between the increase in incidence of papillary thyroid carcinoma in Crete and exposure to radioactive agents

The mean gamma-ray distribution in Crete during the years after the nuclear accident at Chernobyl and its correlation with the Papillary Thyroid Cancer (PTC) distribution was identified. A total of 4285 patients underwent total thyroidectomy in our centre between 1990 and 2012. Data of gamma-ray (nSv/h) distribution were selected from the Greek Statistical Authorisation. A geo-spatial statistical model was used to estimate the expected number of patients with PTC and Kriging interpolation prediction model to estimate their distribution. Geographical weighted regression was performed to estimate the risk of PTC in relation to gamma ray distribution. All factors that were examined were found to be statistically significant for PTC distribution in Crete. Gamma-ray was determined as a significant risk factor (OR = 2.89; 95% CI = 1.682-4.989; p value = 0.03). There is a significant correlation between gamma-ray exposure and the increased prevalence of the PTC suggesting that the former may have been a significant risk factor.