Classic tumor markers in gastric cancer. Current standards and limitations

The progress made in the last few years made available a large amount of information that needs to be integrated and ordered by oncologists. Tumor markers are one of the pieces that physicians need to fit into the bigger puzzle. This article will detail the most frequent etiologies for the surges in the carcinoembryonic antigen (CEA), cancer-related antigen 72-4 (CA 72-4), cancer-related antigen 19-9 (CA 19-9) serum levels and their indications. Although tumor markers are an invaluable asset to medical practice, their role in screening, diagnosis and oncologic treatment remains poorly standardized. Ongoing or future clinical trials will shed light on pending problems.