Expression and clinical significance of YKL-40 protein in epithelial ovarian cancer tissues.

Background and Objective: Overexpression of YKL-40 has been detected in the sera from patients with various kinds of malignant tumors, including epithelial ovarian cancer. Moreover, YKL-40 expression is closely related to clinical phenotypes of some malignant tumors. This study was to investigate the expression and clinical significance of YKL-40 protein in epithelial ovarian cancer tissues. Methods: Protein expression of YKL-40 was detected by immunohistochemistry (IHC) using tissue microarray (TMA) consisting of 86 specimens of epithelial ovarian cancer and 20 specimens of normal ovarian tissues. The correlations of YKL-40 expression to clinical features and prognosis, as well as to the expression of clusterin protein in epithelial ovarian cancer were evaluated. Results: The expression of YKL-40 in all normal ovarian tissues was negative or at low levels. In 74 evaluable specimens of epithelial ovarian cancer, overexpression of YKL-40 was detected in 42 cases (56.8%). YKL-40 expression was closely associated with the clinical stage of epithelial ovarian cancer (p < 0.0001). The overall survival time in patients with overexpression of YKL-40 was significantly shorter than that in patients with normal expression of YKL-40 (p = 0.0389). Moreover, expression of YKL-40 protein was positively correlated with that of clusterin protein in epithelial ovarian cancer (p < 0.0001). Conclusion: YKL-40 may be used as a new molecular marker to predict the prognosis of epithelial ovarian cancer.