MODELING OF SERIAL CARCINOEMBRYONIC ANTIGEN CHANGES IN COLORECTAL-CANCER

Carcinoembryonic antigen (CEA) is a tumour marker mainly used for dete ction of recurrent colorectal cancer. CEA series in 295 patients, who had a macroscopic radical resection of a primary colorectal cancer wer e studied. A kinetic model was fitted to CEA series of individual pati ents. Applying the kinetic model recurrences were identified with a se nsitivity of 70-80% and specificity of 80-90%. Simulations were perfor med in order to find the optimal sampling strategy for CEA during foll ow-up. Simulations showed that CEA determinations at a few weeks inter val between would be optimal for early detection of recurrences.