THE UTILITY OF MONITORING CARCINOEMBYRONIC ANTIGEN DURING SYSTEMIC THERAPY FOR ADVANCED COLORECTAL-CANCER

To determine if pre-treatment serum carcinoembryonic antigen (CEA) lev els or changes in CEA values during treatment have prognostic value, w e reviewed five prior fluorouracil/leucovorin-based trials and identif ied 125 colorectal cancer patients with no prior chemotherapy for meta static disease in whom CEA values were available. Although pre-treatme nt serum CEA values did not predict for clinical response or time to p rogression, serial monitoring of CEA appeared to be useful in patients with an elevated pretreatment CEA, particularly when a decrease in CE A occurred in concert with radiographic evidence of disease response. The CEA nadir was a strong prognostic variable with respect to time to disease progression. A consistent rise in CEA values over the minimum value signals the need for radiographic reassessment of the patient's disease status to rule out disease progression.