Objective: To assess the clinical relevance of serum secretory leukocyte protease inhibitor (SLPI) levels in distinguishing patients with ovarian cancers from those with benign ovarian cysts, we determined concentrations with reference to the FIGO stage and other clinical characteristics.
Methods: Preoperative serum SLPI levels were measured in women with invasive epithelial ovarian cancer (n = 55), benign ovarian cysts (n = 25), or normal controls (n = 38) using an enzyme-linked immunosorbent assay (ELISA).
Results: The serum SLPI concentration was significantly elevated in the ovarian cancer patients (median 67 ng/ml, interquartile range 26-124 ng/ml) as compared to the benign cyst patients (37 and 25-66 ng/ml) or healthy women (32 and 25-43 ng/ml). Using an SLPI cutoff of 50 ng/ml and a CA125 cutoff of 30 units/ml, with both markers elevated the sensitivity was 95%, the specificity was 100%, the positive predictive value was 100%, and the negative predictive value was 89% between the malignant and benign cyst patients.
Conclusion: Serum SLPI levels could be useful for differentiating benign ovarian cysts from malignancies and to improve the specificity of diagnosis.