Serum levels of angiogenetic cancer biomarkers in men undergoing prostate biopsy. Preliminary data

Abstract

Background: The reduction of the number of negative prostate biopsies in patients with elevated serum PSA represents a major challenge. Several angiogenetic biomarkers are involved in carcinogenesis and cancer progression. The aim of our preliminary study was to investigate if their serum levels might be related to prostate cancer detection. Patients and Methods: Angiopoietin 2, Follistatin, G-CSF, HGF, IL-8, Leptin, PDGF- BB, PECAM-1, VEGF, PTH were the selected biomarkers for our research. They were measured by BioPlex immunoassay. As a preliminary step, consecutive unselected patients undergoing prostate biopsy for palpable prostate nodule and/or elevated PSA levels were entered. A 12-core transrectal biopsy was planned. The serum levels of the above mentioned biomarkers were related with the histological result of the biopsy. ROC curve analysis was exploited to test the diagnostic accuracy of each biomarker by AUC calculation. A potential cut-off level was computed for each biomarker. Results: Thirty-five consecutive patients were entered in this preliminary study. The median PSA was 6.3 ng/ml (mean: 19.4, range 0.41-364). An altered prostate was found at digital rectal examination in 13 (37%) patients. Transrectal ultrasound gave a median prostate volume of 44.5 cc (mean 48.7; range 15-105cc). Seven patients (20%) had a previous negative biopsy and 5 were receiving dutasteride or finasteride. A median number of 12 biopsy cores was obtained (mean: 12 range 4-24). Prostate cancer was detected in 21 (60%) men. ASAP and PIN were detected in 2 more patients respectively. Among the 9 considered angiogenetic biomarkers, only leptin preliminarily shows an interesting diagnostic accuracy with an AUC of 0,714 (Table 1). At a cut-off value of 2166 pg/ml, leptin demonstrates a sensitivity of 74% and a specificity of 75% with a positive predictive value of 85%. Conclusion: Only leptin, among the 9 studied biomarkers, showed promising diagnostic accuracy for the detection of prostate cancer, suggesting the usefulness of further research.