Abstract：
A steep increase of small papillary thyroid cancers (sPTCs) has been observed globally. A major risk factor for developing PTC is ionizing radiation. The aim of this study is to investigate the spatial distribution of sPTC in Sweden and the extent to which prevalence is correlated to gamma radiation levels (Caesium-137 (Cs-137), Thorium-232 (Th-232), Uranium-238 (U-238) and Potassium-40 (K-40)) using multiple geospatial and geostatistical methods. The prevalence of metastatic sPTC was associated with significantly higher levels of Gamma radiation from Th-232, U-238 and K-40. The association is, however, inconsistent and the prevalence is higher in densely populated areas. The results clearly indicate that sPTC has causative factors that are neither evenly distributed among the population, nor geographically, calling for further studies with bigger cohorts. Environmental factors are believed to play a major role in the pathogenesis of the disease.
摘要：
在全球范围内观察到小乳头状甲状腺癌（sPTC）的急剧增加。发展PTC的主要危险因素是电离辐射。本研究的目的是调查瑞典sPTC的空间分布以及患病率与γ辐射水平相关的程度（铯-137（Cs-137），钍-232(Th-232),铀238（U-238）和钾40（K-40））使用多种地理空间和地统计学方法。转移性sPTC的患病率与Th-232，U-238和K-40的Gamma放射水平显着升高有关。协会是，然而,不一致，人口稠密地区的患病率更高。结果清楚地表明，sPTC的致病因素在人群中分布不均，也不是地理上的，呼吁与更大的队列进一步研究。环境因素被认为在疾病的发病机理中起主要作用。
