On the RET Rearrangements in Chernobyl-Related Thyroid Cancer

Sergei V Jargin

doi:10.1155/2012/373879

Abstract

There is a consensus that Chernobyl accident has induced thyroid cancer increase in children and adolescents. The UNSCEAR report concluded that no somatic disorders other than thyroid cancer were caused by radiation exposure due to the accident except for acute radiation sickness occurred to the people within the Power Plant at the time of the accident. A hypothesis is discussed in this paper that the increase of thyroid cancer was caused predominantly by the screening, overdiagnosis, and registration of nonirradiated persons as Chernobyl victims. A mechanism of thyroid cancer overdiagnosis is described that can be active even today, causing hypertherapy. Older neglected tumors found by the screening shortly after the Chernobyl accident or brought from noncontaminated areas were misclassified as aggressive radiation-induced cancers. Therefore, supposed markers of the radiation-induced thyroid cancer, such as the RET rearrangements, are probably associated with disease duration and tumor progression. The screening effect is obviously dependent on the basis level of medical surveillance: the higher the level, the smaller the screening effect. Absence of any significant increase of thyroid cancer after the Fukushima accident in spite of the vigorous screening would certify the high level of health care in Japan especially for children.

Highlights

Some features of supposedly radiogenic TC must characterize, on average, a later stage of the tumor progression
The RET/PTC3 rearrangements were the most frequent ones during the “first wave” of papillary TC (PTC) after the Chernobyl accident, while RET/PTC1 seems to have predominated in cases with longer latency [13]
Considering uncertainties in regard to the disease onset, from this statement remains a quintessence: RET rearrangements in PTC were associated with increased aggressiveness in terms of pathological stage, the latter, in its turn, being naturally associated with disease duration

Summary

Introduction

Some features of supposedly radiogenic TC must characterize, on average, a later stage of the tumor progression. Chromosomal rearrangements of the tyrosine kinase proto-oncogenes RET, the RET/PTC3 in particular, found in high proportion in papillary TC (PTC) of patients exposed during childhood and adolescence [10, 11], were discussed as possible markers of radiogenic cancer [2, 12].

Results

Conclusion