The value of serological markers in the diagnosis and prognosis of endometriosis: a prospective case-control study

Objective: We analyzed selected well-known and less well-known serum markers that have been proposed for diagnosis and severity assessment of endometriosis, in a case-control study. Study design: This prospective study was carried out in a Clinical Department of Gynecology in Iasi, Romania. Study participants included endometriosis patients, and controls in whom laparoscopy had excluded endometriosis. Each case and control was investigated for serum levels of CA125, TNF, IL-1, IL-6 and IL-8. The data were correlated with clinical symptoms and revised American Fertility Society (rAFS) score and stage, and interpreted by Mann-Whitney U-test and ANOVA regression analysis. Results: Over the course of 1 year, 24 cases of endometriosis and 24 controls of matched age were selected. The rAFS stages were: stage I, 12.5%; stage II, 16.7%; stage III, 58.3%; and stage IV, 12.5%. CA125 levels were over the cut-off of 35 IU/l in 54% of patients (versus 8% of controls), averaging 67.5 (CI95: ±17.5). The sensitivity and specificity were 54% and 91%, respectively, with a p value of <0.001 (statistically significant). For IL-6, 71% of cases and 87% of controls were above the cut-off of 2 pg/ml, with an average of 11.83 ± 7. The sensitivity and specificity were 71% and 12%, respectively, but the difference was not statistically significant, p = 0.071. Other tested serum markers had no discrimination value. A correlation with severity of endometriosis was seen for CA125 (p = 0.03) but not for IL-6, by ANOVA. Conclusion: CA125 correlated with endometriosis screening and severity, indicating its superiority as a marker for further, larger studies.