BACKGROUNDRisk for developing papillary thyroid carcinoma (PTC), the most common endocrine malignancy, is thought to be mediated by lifestyle, environmental exposures and genetic factors. Recent progress in the genome-wide association studies of thyroid cancer leads to the identification of several genetic variants conferring risk to this malignancy across different ethnicities.METHODS AND RESULTSWe set out to elucidate the impact of selected single nucleotide polymorphisms (SNPs) on papillary thyroid carcinoma risk and to evaluate the interactions of these genetic variants with associated diseases for the first time in the Slovak population. Six SNPs (rs966423, rs2439302, rs965513, rs116909374, rs1537424 and rs944289) were genotyped in 86 patients with PTC and 99 healthy control subjects. The association analysis and multivariable modelling of PTC risk by the genetic factors, supplemented with a rigorous statistical validation, were performed. One of the six SNPs rs966423 (DIRC3, OR=1.51, p=0.03) was significantly associated with PTC. Next two SNPs rs965513 (PTCSC2, OR=1.34) and rs116909374 (MBIP, OR=0.44) showed a suggestive association. Haplotype TTC (SNPs located on chromosome 14q13) showed a suggestive association with PTC (p=0.07, OR=1.55). In the PTC group, significant associations were observed between rs966423 (DIRC3) and ischemic heart diseases (p=0.009), rs965513 (PTCSC2) and diabetes mellitus (p=0.04) and haplotype 14q13 and musculoskeletal diseases. Next three associations rs966423 (DIRC3) and arterial hypertension; rs116909374 (MBIP) and other benign diseases; rs1537424 (MBIP) and disorder lipid metabolism, rs965513 (PTCSC2) and anti-Tg (thyroglobulin antibody) showed suggestive associations.CONCLUSIONThese results indicate that germline variants not only predispose to PTC, but may also be related to other risk factors, including associated diseases. However, these associations were only moderate, and further multi-ethnic studies are required to evaluate the usefulness of these germline variants in the clinical stratification of PTC patients (Tab. 8, Ref. 37).
