A new prostate cancer blood test
Zurich – Researchers headed by Wilhelm Krek from ETH Zurich have presented a new strategy for biomarker-based diagnosis of prostate cancer. The researchers said their two-step approach is generally suitable for discovery of serum biomarker signatures corresponding to cancer-causing mutations and subsequent verification (Proc. Natl. Acad Sci USA, doi/10.1073/pnas.1013699108. Comparing wild-type and Pten-null mice’s serum proteins by quantitative proteomics, Krek et al. identified 775 N-linked glycoprotein serum biomarkers. Pten is a prostate cancer biomarker and one of the tumour-suppressors most commonly inactivated in human cancers. From this subproteome, they identified relevant proteins leading to PTEN inactivation in humans. By comparison of the relevant biomarkers with serum proteins occurring in 143 patients with prostate cancer or benign prostatic hyperplasia, they identified 39 ortholog human proteins. Bioinformatic prioritisation of the potential signatures led to a 4-protein diagnostic signature that showed 79% specificity and 85% sensitivity in distinguishing patients with prostate cancer and benign prostatic hyperplasia. The researchers say the signature is suitable for staging of prostate cancer in combination with other diagnostic tests and could prevent current PSA-based over-diagnosis of prostate cancer patients.