Antibody array profiling reveals serum TSP-1 as a marker to distinguish benign from malignant prostatic disease.
BACKGROUND: Blood protein markers that provide more accurate or earlier diagnosis of prostate cancer should have a positive impact on prostate cancer treatment and management. METHODS: Serum samples from control subjects and patients with benign or malignant prostatic disease were analyzed on antibody arrays targeting multiple candidate prostate cancer markers and detected with two-color, rolling-circle amplification (TC-RCA). The measurements of certain antibodies were validated using immunoblots, immunoprecipitation/mass spectrometry, and sandwich immunoassays. RESULTS: Several potential disease-associated protein alterations were uncovered. The most significant was thrombospondin-1, which was strongly elevated in patients with benign prostatic disease and repressed in patients with prostate cancer. Thrombospondin-1 levels did not correlate with prostate-specific antigen (PSA) levels and differentiated benign from malignant disease with 79% sensitivity and 81% specificity. CONCLUSIONS: The measurement of thrombospondin-1 could be used to assist the decision to obtain a biopsy in men with suspected prostate cancer, which could lead to a reduction in the number of unnecessary prostatic biopsies.