Instability of microsatellites in radiation-associated thyroid tumours with short latency periods

Purpose: To determine the instability of microsatellite sequences in post-C hernobyl thyroid tumours from children and young adults, and to ascertain w hether they correlated with the age of the patient at the time of the accid ent and the tumour latency period. Materials and methods: The stability of 26 microsatellite markers was inves tigated in 122 radiation-associated thyroid tumours (96 children, 26 adults ) from Belarus and 39 spontaneous thyroid tumours (adults) from Munich with out radiation history. Results: A significant correlation between patient age at the time of the a ccident and the instability of microsatellite sequences was established. Al so, a high instability of microsatellite sequences was found in 28 early th yroid tumours from Belarus with latency periods of 6-8 years, in contrast t o a low instability of microsatellites in 91 tumours emerging 9-11 years af ter the accident. Microsatellite instability in the reference group from Mu nich proved similar to the early thyroid tumours from Belarus. Conclusion: Early, fast-growing and aggressive post-Chernobyl thyroid tumou rs are characterized by an increase in microsatellite instability.