Progression criteria for cancer antigen 15.3 and carcinoembryonic antigen in metastatic breast cancer compared by computer simulation of marker data

Background: We investigated the utility of computer simulation models for p erformance comparisons of different tumor marker assessment criteria to def ine progression or nonprogression of metastatic breast cancer. Methods: Clinically relevant values for progressive cancer antigen 15.3 and carcinoembryonic antigen concentrations were combined with representative values for background variations in a computer simulation model. Fifteen cr iteria for assessment of longitudinal tumor marker data were obtained from the literature and computerized. Altogether, 7200 different patients, each based on 50 measurements, were simulated. With a sampling interval of 4 wee ks, the monitoring period for each event was similar to 3.8 years. Results: Modulation of the background variation, the starting concentration s, and the cutoffs enabled identification of criteria that were robust agai nst false-positive signals of progression. Conclusions: The computer simulation model is a fast, effective, and inexpe nsive approach for comparing the diagnostic potential of assessment criteri a during clinically relevant conditions of steady-state and progressive dis ease. The model systems can be used to generate tumor marker assessment cri teria for a variety of malignancies and to compare and optimize their diagn ostic performance. (C) 2000 American Association for Clinical Chemistry.