Background: Papillary thyroid cancer (PTC) is the cardinal histologic type of
thyroid cancer, which is the most prevalent kind of endocrine malignancy. The
expression of IL-6 is found higher in thyroid carcinoma (THCA) samples than paired
normal tissues based on The Cancer Genome Atlas (TCGA) and Genotype-Tissue
expression (GTEx) database. In this study, we aimed to investigate the association
between interleukin-6 (IL-6) polymorphisms and the PTC risk.
Methods: A case-control study was designed using the following data: 241 PTC patients
and 463 healthy controls. Five single nucleotide polymorphisms (SNPs) in IL-6 were
selected and genotyped using Agena MassARRAY technology.
Results: Our results revealed that SNP rs1800796 was associated with an increased
PTC risk in co-dominant model (p = 0.042) and dominant model (p = 0.027). Rs1524107
was also a risk factor for PTC susceptibility in co-dominant model (p = 0.003), dominant
model (p = 0.002) and log-additive model (p = 0.044). Moreover, rs2066992 significantly
increased the PTC risk in co-dominant model and dominant model (p = 0.011, p = 0.009,
respectively). Additionally, rs2069837 variant elevated the PTC risk based on dominant
model (p = 0.041). In silico analysis, GTEx results for rs1800796, rs1524107 and
rs2066992 variants are known to be associated with IL-6 gene expression. Using
HaploReg, we found rs1800796, rs1524107 and rs2066992 in LD with functional
Conclusion: Our study indicates that IL-6 variants may be a risk factor involved in the
pathogenesis and development of PTC.