Intratumoral interleukin-6 predicts ascites formation in patients with epithelial ovarian cancer: A potential tool for close monitoring

BACKGROUND: The implication of IL-6 in the pathogenesis of epithelial ovarian cancer (EOC) is well documented. Accordingly, the clinicopathological significance of this cytokine in patients’ ascites fluid or serum has largely been investigated. Since the main source of IL-6 secreted into the biological fluids is the tumor tissue, this study was designed to investigate the status and possible clinical relevance of the IL-6 expression in an array of EOC tissue specimens. METHODS: Tissue samples obtained from ninety-eight consecutive patients with EOC were studied using immunohistochemistry. Clinicopathological characteristics and treatment related factors were collected from patient files. The relationship between the expression of the protein of interest and the study endpoints of disease-free survival (DFS) and overall survival (OS) were analyzed using the Kaplan-Meier method. For evaluating the predictive value of IL-6, logistic regression and cox proportional hazards models were employed. RESULTS: An upregulation of IL-6 expression was observed in EOC tissues as compared with the normal samples (p < 0.0001). As regards the clinical relevance, IL-6 failed to predict OS, DFS and response to the platinum-based chemotherapy in EOC patients. In multivariate analysis, however, IL-6 was identified as an independent predictive factor for the development of post-treatment ascites (p:0.033). CONCLUSIONS: Having the capability to predict the ascites formation, IL-6 might serve as a biomarker and a useful tool in EOC for monitoring purposes. IL-6 targeting for the prevention of the ascites development is a potential avenue for further investigation.