Present status of serum markers.

Tumor markers presently in use generally meet only one or two of the criteria for the ideal marker, which are: tumor specificity, correlation with tumor bulk and stage of the disease, decrease to normal after successful treatment, and rise prior to clinical manifestations of recurrence. In addition, virtually all are elevated in some benign conditions. Currently their greatest usefulness is for confirmation of clinical suspicion and for monitoring known disease. Some tumor markers which are not effective as screening tests can be used to evaluate the patient's response to therapy. The discovery of oncogenes holds great promise for a new generation of tumor markers. Major breakthroughs in the fields of molecular biology and tumor immunology seem imminent with eventual application possibly in the treatment of cancer.