Measurement of blood E2F3 mRNA in prostate cancer by quantitative RT-PCR: a preliminary study

The use of serum prostate-specific antigen (PSA) measurements necessitates biopsies for accurate prostate cancer (CaP) diagnosis. Overall efficiency of accurate diagnosis, when PSA levels are used alone, is less than 60%. E2F3 was evaluated as an alternative biomarker using patient blood samples. Expression levels were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and correlated with accurate clinicopathological data. Statistical analysis demonstrated significant differences in E2F3 expression levels (p<0.0001), and high levels of discrimination (receiver operator curve/area under curve analysis values (AUC) >0.88), in particular at early stages of disease development, between benign disease and localized CaP. Limited levels of discrimination were observed at the later stages of disease development, between localized and metastatic disease (p=0.076, AUC=0.633). A cut-off point of 0.34 with high specificity for benign disease (92.3%) and sensitivity for CaP diagnosis (81.0%) was identified. At this cut-off point, 85% patients were correctly diagnosed with either malignant or benign disease. This study demonstrates the strength of E2F3 as a potential marker for discriminating benign and malignant disease, addressing the current limitations of serum PSA measurements.