Is CRP Elevated with Ovarian Cancer?
Yes, C-reactive protein (CRP) is frequently elevated in patients with ovarian cancer, particularly in those with epithelial ovarian cancer (EOC), advanced-stage disease, and larger residual tumor burden.
Evidence for CRP Elevation in Ovarian Cancer
Diagnostic Utility
Median CRP levels are significantly elevated in epithelial ovarian cancer patients (1.36 mg/dL) compared to those with benign ovarian masses (0.5 mg/dL), with statistical significance (p<0.001). 1
CRP independently predicts the presence of malignant ovarian masses with an odds ratio of 5.3 (95% CI: 3.8-7.4), even after adjusting for CA-125 levels and patient age. 1
The sensitivity and specificity of CRP for identifying malignant ovarian masses are 49.8% and 84.1%, respectively, with a positive predictive value of 57.1% and negative predictive value of 79.8%. 1
Correlation with Disease Characteristics
In patients with epithelial ovarian cancer, elevated CRP significantly correlates with advanced FIGO stage (p<0.001), larger residual tumor mass after surgery (p<0.001), and older patient age (p=0.04). 1
CRP elevation does not correlate with tumor grade (p=0.2) or histologic subtype (p=0.4), suggesting it reflects tumor burden and systemic inflammation rather than specific tumor biology. 1
Risk Assessment and Prognosis
Women in the highest tertile of CRP have a 34% increased risk of developing ovarian cancer compared to those in the lowest tertile (OR=1.34; 95% CI: 1.06-1.70). 2
The association is particularly strong when CRP is measured from serum samples (OR=1.99; 95% CI: 1.30-3.07) and in studies with follow-up periods longer than 10 years (OR=1.41; 95% CI: 1.18-1.70). 2
Longitudinal increases in individual CRP concentrations over time are associated with a 90% increased risk of ovarian cancer (OR=1.90; 95% CI: 1.12-3.23), suggesting that inflammation precedes cancer development. 3
CRP levels >10 mg/L versus ≤1 mg/L are associated with a 2.16-fold increased risk of invasive ovarian cancer (95% CI: 1.23,3.78). 4
Prognostic Significance
Elevated pretreatment CRP is an independent predictor of shorter disease-specific survival in epithelial ovarian cancer patients, regardless of clinical stage or optimal surgery rate. 5
The CRP-to-albumin ratio (CRP/Alb) is superior to CRP alone for predicting disease-specific survival, with elevated ratios (>0.048) associated with poor outcomes in both early-stage and advanced-stage patients. 5
Clinical Context and Limitations
Important Caveats
CRP is not specific for ovarian cancer and can be elevated in numerous benign conditions including endometriosis, pelvic inflammatory disease, and other inflammatory states. 6, 7
CRP should not be used as a standalone screening tool for ovarian cancer but rather as an adjunctive marker when combined with imaging findings and CA-125 levels. 1
In postmenopausal women specifically, the combination of clinical examination, imaging (transvaginal ultrasound with Doppler), and CA-125 remains the standard approach, with CRP serving as a supplementary inflammatory marker. 6
Practical Application
When evaluating ovarian masses, measure CRP alongside CA-125 to improve diagnostic accuracy, as CRP provides independent predictive value beyond CA-125 alone. 1
Serial CRP measurements may be useful for monitoring disease progression and treatment response, particularly in patients with established epithelial ovarian cancer. 3, 5
Consider that rising CRP levels over time, even before clinical symptoms appear, may indicate increased cancer risk and warrant closer surveillance. 3