The diagnostic and prognostic value of interleukin-6 in patients with soft tissue sarcomas.

The presence of systemic inflammation has been reported to be associated with poor prognosis in patients with soft tissue sarcoma (STS). The cytokine interleukin-6 (IL-6) has pleiotropic effects on various cell types in the tumor microenvironment. The aim of the present study was to determine whether serum IL-6 levels could be useful to assume the differentiation of benign soft tissue tumors from STS and to investigate the possible value of IL-6 for survival and oncological events in patients with STS. The medical records of 99 patients who underwent surgical resection were retrospectively reviewed. Serum IL-6 levels (median: 9.04 pg/ml) in patients with STS were statistically higher than those (3.31 pg/ml) in patients with benign soft tissue tumors. Our analyses confirmed that tumor size and IL-6 level were significant predictors of STS diagnosis. Next, we examined the relationship between IL-6 levels and survival in the 59 patients with STS. C-reactive protein levels, hemoglobin levels, and tumor grade were strongly correlated with IL-6 levels. Tumor grade and IL-6 level remained significant factors for survival and event-free survival. We suggest that measurement of IL-6 levels may be a useful method for identifying patients who are at a high risk of STS and tumor-related death.