Chromosomal Rearrangements of RET/PTC in Post-Chernobyl Thyroid Cancer

What is it about?

A hypothesis is proposed here that RET rearrangements in papillary thyroid cancers are related to the disease duration and tumor progression. The most common RET rearrangements are RET/PTC1 and RET/PTC3. RET/PTC1 is more prevalent in classic papillary thyroid carcinoma (PTC), its diffuse sclerosing variant, and papillary microcarcinoma; while RET/PTC3 is frequently found in less differentiated solid PTC. RET/PTC3 is associated with larger tumor size and multifocality in sporadic pediatric PTC. There were many late-stage tumors among the first-wave Chernobyl PTCs that tended to be larger and less differentiated than those detected later. The high proportion of late-stage cases shortly after the accident is explained by the neglected cases found by the screening and also by the fact that some non-exposed patients were registered as radiation-exposed. The screening was productive because of the reservoir of undiagnosed cases in the population: registered incidence of thyroid cancer (TC) among children and adolescents prior to the Chernobyl disaster was low in the Soviet Union compared to other developed countries. In conclusion, RET rearrangements, especially RET/PTC3 seem to correlate with the tumor progression. If the hypothesis defended here is correct, a low prevalence of RET/PTC3 among sporadic TC is circumstantial evidence of efficient cancer diagnosis and early detection in a given country.

Featured Image