Role of a combined soluble interleukine-2 receptor alpha (sIL-R2α) and CA-125 serum marker assay for detection of ovarian cancer

Detection of ovarian cancer can be improved using a combined diagnostic test consisting of Ca-125 and serum interleukine-2 receptor alpha (sIL-R2α) at a particular threshold. The objective of the study was to evaluate the accuracy of a diagnostic marker assay that combined Ca-125 and serum interleukine-2 receptor alpha. A case-control study of 38 patients with ovarian cancer, 40 patients with benign ovarian diseases and 31 age-matched healthy controls was designed. Ca-125 and sIL-2Rα were detected in patients' serum by standardized chemiluminescent immunometric assays. For Ca-125, a standard cutoff level of 21 U/ml was applied and for sIL-R2α — two cutoff levels were calculated from women included in the control group — one as a mean concentration and the other as an upper limit of a 95% confidence interval. Mean serum concentrations among ovarian cancer patients for CA125 and sIL-2Rα were 265.9 ± 40.2 U/ml and 651.0 ± 50.5 U/ml, respectively. The upper limit of the 95% confidence interval for a healthy control group of women was 304.5 U/ml for sIL-2Rα. Sensitivity and specificity of 89.4% and 85.9% was achieved when CA125 was combined together with sIL-2Rα at a threshold of 304.5U/ml with the condition that both markers are elevated. Sensitivity and specificity of 92.5% and 88.4% was observed when both biomarkers were applied to menopausal women. Serum sIL-2Rα in combination with CA125 can be used as a differential diagnostic test for ovarian cancer at a specific threshold, especially among menopausal women.