Serum carcinoembryonic antigen pre-operative level in colorectal cancer: revisiting risk stratification

Background: Biomarkers may play a role as predictive and prognostic factors in colorectal cancer patients. The aims of the study were to verify the prognostic role of pre-operative serum carcinoembryonic antigen (CEA) level in predicting overall survival and risk of recurrence in a cohort of colorectal cancer patients and to evaluate optimal cut-off values. Methods: A retrospective cohort analysis was performed on colorectal cancer patients undergoing elective curative surgery between 2004 and 2019 at an Italian Academic Hospital. Main outcomes were overall survival, disease-free survival at 3-years and risk of local, loco-regional and distant recurrence during follow-up. A receiver operating characteristic (ROC) curve analysis was plotted using CEA pre-operative values and follow-up data in order to estimate the optimal cut-off values. Results: A total of 559 patients were considered. The mean CEA value was 12.1 ± 54.1 ng/mL, and the median 29.3 (0–4995) ng/mL. The ROC curve analysis identified 12.5 ng/mL as the best CEA cut-off value to predict the risk of metastatic development after surgery in stage I–III colorectal cancer patients, and 10 ng/mL as the best CEA cut-off value to predict overall survival and disease-free survival in stage III–IV patients. These data suggest a stratification of colorectal cancer patients in three classes of risk: a low risk class (CEA <10 ng/mL), a moderate risk class (CEA 10–12.5 ng/mL) and a high risk class (CEA >12.5 ng/mL). Conclusion: In conclusion, pre-operative serum CEA measurements could integrate information to enhance patient risk stratification and tailored therapy.