AGE-RELATED ACTIVATION OF THE TYROSINE KINASE RECEPTOR PROTOONCOGENESRET AND NTRK1 IN PAPILLARY THYROID-CARCINOMA

Oncogenic rearrangements of RET and NTRK1 proto-oncogenes are frequent ly detected in papillary thyroid carcinomas. Several studies have show n an association between ionizing radiation and development of this tu mor type. In addition in vitro irradiation of tumor cell lines induced rearrangements of RET similar to those observed in human papillary th yroid carcinomas. These two observations could be related to the repor ted increased incidence of papillary thyroid carcinomas in children li ving in contaminated areas around Chernobyl, given that it has been de monstrated that about 60% of them presents a RET oncogenic activation. However, this high frequency of RET positivity in radiation exposed c hildren does not rule out the possibility that age could also play a r ole in the development of RET positive tumors. To assess this possibil ity we looked for a relationship between the presence of RET and NTRK1 oncogenic rearrangements and age at surgery in a sample of 92 consecu tive patients. Our results show that, in papillary thyroid carcinoma, the frequency of RET and NTRK1 activation is significantly higher in t he group of patients aged 4-30 years, thas supporting the concept that age could be contributing to this thyroid specific carcinogenic proce ss.