Preoperative C-reactive protein serum levels as a predictive diagnostic marker in patients with adnexal masses

Abstract

Objective: To evaluate C-reactive protein (CRP) serum levels as a preoperative predictive marker for ovarian cancer in patients with adnexal masses.

Methods: CRP serum levels of 1843 adnexal masses and subsequent surgery were investigated (patients with benign ovarian tumors: n=1423; borderline tumor of the ovary [BTO]: n=83; EOC: n=337). Test characteristics and predictive values of CRP serum levels were investigated by univariate analysis and multivariate binary logistic regression models.

Results: Median (interquartile range) serum CRP levels in patients with benign ovarian tumors, BTO, and EOC were 0.4 (0.1-0.6)mg/dL, 0.5 (0.2-0.9)mg/dL, and 1.6 (0.5-5.4)mg/dL, respectively (p<0.001). Sensitivity and specificity of the combination of CRP and CA-125 was 80.1% and 90.8%, negative predictive value (NPV) and positive predictive value (PPV) was 92.2% and 76.9%, respectively. In univariate and multivariate analysis, CRP serum levels were independently associated with presence of BTO and EOC (HR 6.7 [5.2-8.5], p<0.001 and HR 2.2 [1.4-3.3], p<0.001). The combination of CRP and CA-125 serum levels resulted in a number needed to treat of 2.11 to detect one case of EOC or BTO.

Conclusion: CRP serum levels independently predicted the presence of BTO and EOC in patients with suspicious adnexal masses. CRP serum levels seem to be of additional value to CA-125 in the preoperative differential diagnosis of adnexal masses and might be particularly in combination with CA-125 clinically useful.