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

Purpose: To determine the instability of microsatellite sequences in post-Chernobyl thyroid tumours from children and young adults, and to ascertain whether they correlated with the age of the patient at the time of the accident and the tumour latency period.

Materials And Methods: The stability of 26 microsatellite markers was investigated in 122 radiation-associated thyroid tumours (96 children, 26 adults) from Belarus and 39 spontaneous thyroid tumours (adults) from Munich without radiation history.

Results: A significant correlation between patient age at the time of the accident and the instability of microsatellite sequences was established. Also, a high instability of microsatellite sequences was found in 28 early thyroid tumours from Belarus with latency periods of 6-8 years, in contrast to a low instability of microsatellites in 94 tumours emerging 9-11 years after the accident. Microsatellite instability in the reference group from Munich proved similar to the early thyroid tumours from Belarus.

Conclusion: Early, fast-growing and aggressive post-Chernobyl thyroid tumours are characterized by an increase in microsatellite instability.