Serum carcinoembryonic antigen doubling time in patients with recurrent gastrointestinal carcinoma and its relationship to tumor biology and life expectancy

BACKGROUND: The present study was done to determine if carcinoembryonic antigen (CEA) concentration doubling time can predict the course of disease in patients with adenocarcinoma of the gastrointestinal tract and characterize tumor biology. METHODS: CEA doubling times were determined from semilogarithmic plots of CEA concentration time courses in 20 patients with recurrent gastric cancer and 17 with recurrent colorectal cancer. RESULTS: Gastric and colorectal carcinomas showed mean CEA doubling times of 229 days and 85 days, respectively. There were no significant differences with regard to patient age, tumor size, gross appearance and histological differentiation. However, women had shorter CEA doubling times than did men. Flow cytometric analysis showed that tumors with a higher proportion of cells in S-phase (> or = 15%) had significantly shorter CEA doubling times than those with a lower S-phase fraction (< 15%). There was a significant correlation between the CEA doubling time and the length of survival after the initial CEA concentration increase in patients with recurrent gastric and colorectal carcinomas. CONCLUSIONS: CEA doubling time predicts life expectancy in patients with adenocarcinoma of the gastrointestinal tract. Differences in survival time are closely associated with variations in the biological aggressiveness of individual tumors.