• Tetiana I Bogdanova, Liudmyla Yu Zurnadzhy, Yuri E Nikiforov, Rebecca J Leeman-Neill, Mykola D Tronko, Stephen Chanock, Kiyohiko Mabuchi, Ilya A Likhtarov, Leonila M Kovgan, Vladimir Drozdovitch, Mark P Little, Maureen Hatch, Lydia B Zablotska, Viktor M Shpak, Robert J McConnell, and Alina V Brenner.
• Laboratory of Morphology of Endocrine System, State Institution 'V.P. Komisarenko Institute of Endocrinology and Metabolism of Academy of Medical Sciences of Ukraine', Vishegorodskaya Street 69, Kyiv 254114, Ukraine.
• Br. J. Cancer. 2015 Dec 1; 113 (11): 1556-64.

BackgroundThere are limited data on the histopathology of papillary thyroid carcinomas (PTCs) diagnosed in irradiated populations. We evaluated the associations between iodine-131 dose and the histopathological characteristics of post-Chernobyl PTCs, the changes in these characteristics over time, and their associations with selected somatic mutations.MethodsThis study included 115 PTCs diagnosed in a Ukrainian-American cohort (n=13,243) during prescreening and four successive thyroid screenings. Of these PTCs, 65 were subjected to somatic mutation profiling. All individuals were <18 years at the time of the Chernobyl accident and had direct thyroid radioactivity measurements. Statistical analyses included multivariate linear and logistic regression.ResultsWe identified a borderline significant linear-quadratic association (P=0.063) between iodine-131 dose and overall tumour invasiveness (presence of extrathyroidal extension, lymphatic/vascular invasion, and regional or distant metastases). Irrespective of dose, tumours with chromosomal rearrangements were more likely to have lymphatic/vascular invasion than tumours without chromosomal rearrangements (P=0.020) or tumours with BRAF or RAS point mutations (P=0.008). Controlling for age, there were significant time trends in decreasing tumour size (P<0.001), the extent of lymphatic/vascular invasion (P=0.005), and overall invasiveness (P=0.026).ConclusionsWe determined that the invasive properties of PTCs that develop in iodine-131-exposed children may be associated with radiation dose. In addition, based on a subset of cases, tumours with chromosomal rearrangements appear to have a more invasive phenotype. The increase in small, less invasive PTCs over time is a consequence of repeated screening examinations.

54 keywords...

hide…