Identification of serum biomarkers for colon cancer by proteomic analysis

TLDR

Colorectal cancer is frequently diagnosed at a late stage with poor prognosis, and although early detection improves outcomes, current serum tests lack sufficient sensitivity and specificity, limiting their clinical utility. The study aims to identify new serum biomarkers for early detection of colorectal cancer. The authors used surface‑enhanced laser desorption/ionisation (SELDI) to analyze the serum proteome of 62 CRC patients and 31 controls. They identified complement C3a des‑arg, α1‑antitrypsin, and transferrin as diagnostic markers, and an ANN trained on SELDI peak intensities classified patients with 95 % sensitivity and 91 % specificity.

Abstract

Colorectal cancer (CRC) is often diagnosed at a late stage with concomitant poor prognosis. Early detection greatly improves prognosis; however, the invasive, unpleasant and inconvenient nature of current diagnostic procedures limits their applicability. No serum-based test is currently of sufficient sensitivity or specificity for widespread use. In the best currently available blood test, carcinoembryonic antigen exhibits low sensitivity and specificity particularly in the setting of early disease. Hence, there is great need for new biomarkers for early detection of CRC. We have used surface-enhanced laser desorbtion/ionisation (SELDI) to investigate the serum proteome of 62 CRC patients and 31 noncancer subjects. We have identified proteins (complement C3a des-arg, α1-antitrypsin and transferrin) with diagnostic potential. Artificial neural networks trained using only the intensities of the SELDI peaks corresponding to identified proteins were able to classify the patients used in this study with 95% sensitivity and 91% specificity.