Author(s): Sergei V Jargin
Thyroid cancer had been rarely diagnosed in children and adolescents prior to the Chernobyl accident in the areas, where the contamination later occurred, so that there was a pool of neglected cases. Detection by the screening of advanced tumors, interpreted as aggressive radiogenic cancers, coincided with the peak of RET/PTC3 rearrangements. The hypothesis discussed here is that successive waves of thyroid cancer after the Chernobyl accident in people exposed to the fallout at an early age, each wave with different molecular and morphological features, were determined not by radiation but by changing modalities of screening and diagnostics, their improvement with time, and exhaustion by the screening of the pool of advanced cancers. The cohort of papillary thyroid carcinoma in children, diagnosed during the first decade after the Chernobyl accident, where RET/PTC3 was the most prevalent rearrangement type, has been exceptional in the more developed parts of the world: in most series, RET/PTC1 has been the most common type of RET/PTC rearrangement. Considering that the data on sporadic tumors are mainly from more developed countries, this must be caused by the averagely earlier tumor detection. In conclusion, RET/PTC chromosomal rearrangements in papillary thyroid carcinoma RET/PTC3 in particular, probably correlate with disease progression.