Soluble epidermal growth factor receptor (sEGFR/sErbB1) as a potential risk, screening, and diagnostic serum biomarker of epithelial ovarian cancer.

Epithelial ovarian cancer (EOC) is the leading cause of death from gynecologic malignancies in the United States, for which risk assessment, screening, and diagnostic tests are needed. We have shown previously that women with stage III/IV EOC have lower serum p110 sEGFR/sErbB1 (Soluble Epidermal Growth Factor Receptor) concentrations than healthy women. Here, we show that serum p110 sEGFR/sErbB1 is the product of a 3-kb EGFR/ERBB1 alternate transcript. We report that serum sEGFR concentrations in stage I/II and stage III/IV EOC patients are significantly lower than in healthy women, and that serum sEGFR concentrations are not associated with disease stage or tumor grade. Logistic regression models show that: (a) lower serum sEGFR concentrations are associated significantly with a greater risk of EOC; (b) the risk associated with lower serum sEGFR concentrations is reduced by older age or menopause; and (c) age- or menopausal status-specific cutoff values for sEGFR concentration are appropriate. Receiver operating characteristic curves indicate that: (a) serum sEGFR concentrations are more effective in discerning stage III/IV than stage I/II EOC cases from healthy women; and (b) sEGFR concentrations have an 89% probability of correctly discerning EOC patients from healthy women when accounting for effect modification by age. By maintaining a test specificity of approximately 95% across strata of age or menopausal status with appropriate cutoff values, we observe that sEGFR concentrations are most useful for detecting stage I/II (sensitivity: 64-67%) and stage III/IV (sensitivity: 75-81%) EOC in young, premenopausal women. We conclude that serum sEGFR concentrations warrant additional investigation in the risk assessment, early detection, and/or diagnosis of EOC.