A common interleukin-6 promoter polymorphism in patients with vulvar cancer

Besides its important role in immune response and inflammatory processes the cytokine interleukin-6 (IL-6) is crucially involved in carcinogenesis. A common polymorphism within the gene encoding IL-6 (IL6) is known to alter IL-6 protein expression and has been associated with patients' prognosis in various malignancies. No data are available with respect to vulvar cancer. Therefore, we determined the prognostic potential of the common -174(G-->C) single nucleotide polymorphism in the promoter region of IL6 in a series of patients with this disease.

The IL6 promoter polymorphism was investigated in 81 Caucasian patients with surgically treated squamous cell vulvar cancer using pyrosequencing. Results were correlated with clinical data.

No association was ascertained between the IL6 promoter polymorphism and the investigated clinicopathologic parameters, ie, tumor stage, lymph node involvement, tumor grade, and patient's age at diagnosis. In an univariate analysis, lymph node involvement and patients' age at diagnosis were associated with patient prognosis. In a multivariate analysis, including tumor stage and lymph node involvement as established prognostic factors and the IL6 promoter polymorphism, lymph node involvement, and the presence of at least one mutant allele, but not tumor stage, were associated with increased disease-free and overall survival.

Our data suggest that the IL6 -174(G-->C) promoter polymorphism might serve as an additional prognostic parameter in patients with vulvar cancer.