[Tumor markers in colorectal cancer].

INTRODUCTION In 2008, colorectal cancer represented the third most commonly diagnosed tumor in Spain, and the second tumor with more deaths. Despite the new potential biomarkers in colorectal cancer, there are many challenges that need to be overcome, resulting in a need for the standardization of its determinations. DISCUSSION The continuous advance in tumor disease knowledge makes this review a summary of the current accepted, recommended and studied tumor markers for the diagnosis and monitoring of colorectal cancer, such as fecal markers, tissue markers and serological markers, and various prognostic markers on which there are different lines of treatment in colorectal cancer. CONCLUSIONS Oncological guidelines recommend only a minority of tumor markers for routine use, such as the study of fecal occult blood, CEA determination in the postoperative followup, microsatellite instability to identify people susceptible to hereditary nonpolyposis colorectal cáncer, and mutation of APC in the diagnosis of familial adenomatous polyposis.