Interleukin-10 promoter variants predict HPV-positive tumors and survival of squamous cell carcinoma of the oropharynx

Interleukin-10 (IL-10) plays an important role in a host's defense against human papillomavirus (HPV) infection. IL-10 promoter variants may affect its expression level or functional efficiency and, subsequently, susceptibility to and survival of HPV16-associated squamous cell carcinoma of oropharynx (SCCOP). We determined tumor HPV16 DNA and genotyped three IL-10 promoter polymorphisms in 309 incident patients with SCCOP. Compared with the patients with corresponding common homozygous genotypes, patients carrying variant genotypes of IL-10 rs1800871 and rs1800872 were ~2.5 times more likely to have HPV16 ⁺ tumors among patients with SCCOP. Among HPV16⁺ patients with SCCOP only, compared to those with the corresponding variant genotypes, the patients with IL-10 rs1800871 and rs1800872 CC genotypes had significantly better survival and ~70-80% reduced risk of death/recurrence after multivariable adjustment. Additionally, functional relevance of these variants was characterized to explore the genotype-phenotype correlation. Our findings indicate that IL-10 genetic variants may be associated with tumor HPV16 ⁺ SCCOP and predict survival of HPV16⁺ patients with SCCOP. Larger studies are needed to validate our findings.