RET/PTC3 Rearrangement in Papillary Thyroid Carcinoma

What is it about?

Thyroid cancer had been rarely diagnosed in children and adolescents in the former USSR before the Chernobyl accident, so that there was a pool of neglected cases. Some cases were brought additionally from non-contaminated areas. Detection by the screening of advanced tumors, interpreted as aggressive radiogenic cancers, coincided with the peak of RET/PTC3 rearrangements associated with a more aggressive phenotype and larger tumor size. Percentage of tumors with RET rearrangements declined with time, while among RET-positive tumors the percentage with RET/PTC1 increased and RET/PTC3 decreased. The hypothesis is discussed here that successive waves of thyroid cancer after the Chernobyl accident were determined not by radiation but by changing screening pattern and exhaustion by the screening of the pool of advanced cancers. The percentage of earlier lesions must have been increasing with time. The cohort of papillary thyroid carcinoma in children with predominance of RET/PTC3, diagnosed during the first decade after the accident, has been exceptional in more developed parts of the world. In sporadic thyroid cancer predominated RET/PTC1. The data from less developed countries are scarce, but they agree with the hypothesis presented here: similarly to Chernobyl, RET/PTC3 was the most prevalent form of RET rearrangement in a cohort from India. The incidence of pediatric TC is generally higher in more developed countries probably due to earlier diagnosis and better coverage of the population by medical examinations. In conclusion, RET/PTC chromosomal rearrangements in papillary thyroid carcinoma, the RET/PTC3 in particular, probably correlate with the disease duration and tumor progression. Recent data from Japan agree with this hypothesis: the percentage of RET rearrangements in pediatric thyroid cancers after the Fukushima accident is low; the prevailing rearrangement type is RET/PTC1, which certifies the early detection of malignancies in Japan particularly in children. The last update: https://www.researchgate.net/publication/320208934_Radiation_safety_standards_and_hormesis In Russian: https://www.researchgate.net/publication/316316321_O_perestrojkah_RETPTC_v_rake_sitovidnoj_zelezy_posle_avarii_na_CAES_RETPTC_rearrangements_in_thyroid_carcinoma_after_the_Chernobyl_accident

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