Detection of RET/PTC oncogene rearrangements in Korean papillary thyroid carcinomas

The prevalence of RET/PTC rearrangement in papillary thyroid carcinomas has been found to vary widely in different populations. Recent studies, however, have reported no significant geographical difference between Asian and Western countries. In addition, there are some disagreements about the correlation of RET/PTC expression with clinical aggressiveness. We have performed this study in order to examine the prevalence of RET/PTC-1, RET/PTC-2, and RET/PTC-3 rearrangements in Korean papillary thyroid carcinomas, and to ascertain its clinical relevance. Thyroid tumors from 31 patients histologically confirmed to be papillary carcinomas were included in this study. To find rearrangements, we utilized reverse transcription-polymerase chain reaction (RT-PCR) and automated direct sequencing. Initial and follow-up clinical data were obtained from the patients' medical records. We identified two tumors containing RET/PTC-1 (2/31, 6.5%) and two containing RET/PTC-2 (2/31, 6.5%). However, we could not find RET/PTC-3 rearrangement in any patients (0/31). In conclusion, we report RET/PTC rearrangements in 4 of 31, (12.9%) Korean patients with papillary thyroid carcinomas, a higher prevalence than previously reported in this population.