A case-control study of genotoxicity endpoints in patients with papillary thyroid cancer

Thyroid cancer is one of the fastest growing cancer types worldwide. Using the cytokinesis-block micronucleus (CBMN) and comet assays, we performed a case-control study of 23 untreated papillary thyroid cancer (PTC) patients and 23 healthy volunteers. PTC patients showed higher basal DNA damage in peripheral blood lymphocytes. The CBMN assay indicated that the numbers of micronuclei, nuclear buds, and nucleoplasmic bridges among the cases were 2.67-, 2.79-, and 7.72-fold higher, respectively, than among the controls (p < 0.05). Comet assay tail lengths and tail intensities were 1.20- and 1.94-fold higher, respectively (p < 0.05). In additional, 14 thyroid tissues from PTC patients were probed for Raf-B and Ret expression; all samples were positive for at least one of these proteins.