Epidermal Growth Factor-Containing Fibulin-Like Extracellular Matrix Protein 1 (EFEMP1) Acts as a Potential Diagnostic Biomarker for Prostate Cancer

Background: The aim of this study was to detect the expression of epidermal growth factor-containing fibulin-like extracellular matrix protein 1 (EFEMP1) and estimate its diagnostic value in prostate cancer (PCa). Material/Methods: EFEMP1 expression in serum and urine of patients with PCa, benign controls and healthy controls at mRNA and protein level were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and enzyme- linked immunosorbent assay (ELISA) analysis, respectively. The chi-square test was used to analyze the relationship between EFEMP1 expression and clinical factors of patients with PCa. A receiver operating characteristic (ROC) curve was established to evaluate the potential values of EFEMP1 for the diagnosis of PCa. Results: The relative expression of EFEMP1 was significantly decreased in patients with PCa compared with that in the benign controls and healthy individuals, both at mRNA and protein levels (P<0.05). In the postoperative serum, the EFEMP1 expression was significantly higher than that in preoperative serum at 2 levels. Urine EFEMP1 expression was also down-regulated in patients with PCa compared to that in the other 2 control groups. The low expression of EFEMP1 was obviously affected by Gleason's score, serum PSA, pathological stage, and lymph node metastasis. Moreover, there was a significant inverse correlation between EFEMP1 expression and PSA levels. The ROC curve revealed that EFEMP1 distinguished PCa patients from healthy controls, with a high AUC of 0.908, corresponding with high sensitivity and specificity, which was significantly higher than the PSA value. Conclusions: Serum EFEMP1 is down-regulated and involved in the progression of PCa. It may serve as a useful diagnostic biomarker, with better diagnostic accuracy than PSA in PCa.