Interleukin-6 (IL-6) affects the key parameters of oncogenesis, which increases the cell resistance to apoptosis, the proliferation of cancer cells, angiogenesis, invasion, malignancy, and the ability of tumor cells to respond to anticancer therapy. This study aimed to elucidate the association between IL-6 and IL-6 receptor (IL-6R) expression in tissues and clinical outcomes in patients with soft tissue sarcomas (STSs) because, to our knowledge, this has not been done before. We enrolled 86 patients with histologically-proven localized STSs who underwent surgical resection. The cohort included 48 men and 38 women, with a mean age of 65.6 years. The mean follow-up duration was 40.5 months. The expression of IL-6 and IL-6R was immunohistochemically determined. We analyzed prognostic factors for overall survival (OS) and metastasis-free survival (MFS). High IL-6 expression was observed in 23.3% (20/86), high IL-6R expression in 44.2% (38/86), and high expression of both in 16.3% (14/86) of patients. Multivariate analysis showed that a high expression of both IL-6 and IL-6R was a prognostic factor for OS and MFS. We found that this high expression indicated that the patient had a poor prognosis for OS and MFS.
Keywords: interleukin-6; interleukin-6 receptor; prognosis; soft tissue sarcoma; tissue expression.