Prognostic value of preoperative serum CEA level compared to clinical staging: III. An approach to scoring of prognostic factors in colorectal cancer.

In a clinical study of observed postoperative survival of colorectal cancer patients, we investigated the application of a risk score based on tumor-related prognostic parameters. Six hundred seventy-four patients have been registered for primary surgery of colorectal cancer since 1974 who did not receive further postoperative treatments. The prognostic parameters included operability, tumor extension, and preoperative serum carcinoembryonic antigen (CEA) level. The scoring system was based on the average death-rate ratios of subgroups of patients and their age and sex-matched reference groups derived from the general life table of the population of the Federal Republic of Germany. The individual score sums of the patients exhibited score sum ranges which characterized groups of patients with entirely different observed survival. The prediction of individual survival after primary operation was only partly possible. In the plot of individual survivals vs individual score sums, a marginal risk zone was obtained which evidently represents the zone of maximum expected survival of patients who do not receive further postoperative treatment.