Association between single-nucleotide polymorphisms of BRAF and papillary thyroid carcinoma in a Chinese population

Papillary thyroid cancer (PTC) is a common malignancy that frequently harbors a high prevalence of somatic mutations in the oncogenic BRAF gene. As a novel prognostic molecular marker, this gene has drawn much attention in recent years for its potential utility in the risk prognosis and management of PTC. However, the contribution of the germline variants in this gene to PTC remains unclear. The study herein was aimed to investigate the potential association between the inherited BRAF variants and PTC based on a case-control study.

We selected four single-nucleotide polymorphisms (SNPs) and took a systematic step to interrogate whether these SNPs of BRAF are associated with PTC risk by genotyping these SNPs from 368 patients with PTC and 564 healthy controls.

In comparison of cases and controls for the four SNPs, no differences were observed in the genotypic and allelic frequencies, nor was there evidence of an association between BRAF SNPs and overall risk of PTC. After stratification, however, we found a significantly increased risk of PTC attributed to the SNP variants rs17161747, rs1042179, and rs3748093 for those with a family history of cancer, for smokers, and for both those of age <45 years and nondrinkers, respectively. Further, in the PTC cases, those carrying the rs3748093 variant seemed to be less susceptible to developing lymph node metastases, but more likely to suffer from PTC at an earlier age (<45 years).

These preliminary results may provide evidence for the involvement of the common genetic variants scattered throughout the BRAF oncogene in the prediction of PTC onset and progression. In the future, enlarging the number of samples and performing functional studies in this gene may help to validate whether the association truly exists.