The chemotactic cytokine interleukin-8--a cyst fluid marker for malignant epithelial ovarian cancer?

Due to the difficulties in separating malignant and benign ovarian cysts by transvaginal ultrasound and other techniques, there is a need for biochemical markers in serum or cyst fluids. In the present study we have evaluated the levels of the chemokine interleukin-8 (IL-8) in ovarian cysts. IL-8 is known to be expressed in the normal ovary and to influence proliferation and angiogenesis of several nonovarian types of tumors. Cyst fluids from benign (n = 15) and malignant (n = 13) ovarian tumors were analyzed. The levels of IL-8 were found to be significantly (13-fold) higher in cyst fluids from malignant tumors (18.1 +/- 7.5 ng/ml; mean +/- SE) compared to benign cysts (1.3 +/- 0.7 ng/ml). The plasma levels of IL-8 were considerably lower (2.9 and 0.3% of levels in benign and malignant cyst fluids, respectively) than in cyst fluids. No difference in the plasma levels of patients with benign or malignant tumor could be detected. In contrast, the levels of CA 125 were significantly higher in plasma of patients with malignant disease with the inverse relation in cyst fluids. In conclusion, the levels of IL-8 are markedly elevated in cyst fluid from malignant tumors compared to benign. This specific increase indicates a role for this cytokine in ovarian tumor biology. Copyright 1998 Academic Press.