[Metabolome Analysis of Human Serum: Implications for Early Detection of Colorectal Cancer].

With the recent development of novel technologies capable of comprehensively detecting and accurately identifying small molecules within biological samples--the field of metabolomics--new information about disease biology is emerging. A comprehensive metabolomics strategy was used to discover novel small molecules which were significantly decreased in the serum of colorectal cancer (CRC) patients relative to normal individuals. The metabolite markers, hydroxylated polyunsaturated ultra long-chain fatty acids (hPULCFAs), were characterized using HPLC-coupled tandem mass spectrometry, and a high-throughput screening (HTS) method compatible with conventional triple-quadrupole mass spectrometers in clinical labs. around the world was developed. The HTS method was used to determine serum levels of the 28 carbon-containing hPULCFA C28H46O4 (named GTA-446) in independent clinical validation studies to investigate the effect of tumor removal after surgery, chemo- or radiation therapy and the correlation with age. We have also obtained results from a two-year prospective trial. Serum samples from a representative cohort of physician-referred colonoscopy subjects (n = 4,923) were collected between July 2008 and August 2010. Ninety-eight new CRC cases were detected in the colonoscopy cohort. Overall sensitivity in this cohort was 85.7%, with 86.5% in the early stage (0-II) and 84.8% in the late-stage (III-IV). This trial represents the first prospective study of this magnitude investigating a metabolic biomarker for CRC. The results indicate that pre-colonoscopy screening using serum GTA-446 levels is a viable approach to detecting early-stage CRC.