Cancer biomarker discovery and development in gastrointestinal cancers: early detection research network-a collaborative approach.

Despite the large amount of research and reporting on potential biomarkers in cancer, very few markers have been brought to use in the clinic. Disorganization plays a large part in this low yield. The Early Detection Research Network (EDRN) of the National Cancer Institute has been initiated to foster collaboration among independent institutions/ laboratories to facilitate, standardize, and centralize discovery and validation of candidate biomarkers. EDRN comprises four components: biomarker reference laboratories; biomarker developmental laboratories; clinical epidemiology and validation centers; and a data management and coordinating center. Biomarker validation proceeds through five phases-the preclinical exploratory, clinical assay and validation, retrospective longitudinal, prospective screening, and cancer control phases. A number of candidate markers in colon cancer, esophageal adenocarcinoma, and hepatocellular carcinoma (HCC) currently are moving through the developmental process. Ongoing EDRN collaborations assessing the potential utility of des-gamma carboxyprothrombin (DCP) in discriminating early HCC in patients with cirrhosis and the ability of DNA methylation analysis to predict progression from Barrett's esophagus to esophageal cancer are summarized. EDRN welcomes collaboration in biomarker validation and assembly of sample reference libraries.