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

•Genome integrity of 23 untreated papillary thyroid cancer patients was assessed.•Control group was matched in age, gender, and smoking status.•Untreated patients had elevated micronucleus and comet assay parameters.•All tissue samples from patients were positive for either Raf-B of Ret protein.•Cytogenetic biomonitoring might be used for better cancer prevention. 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