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The utility and prognostic value of CA 19-9 and CEA serum markers in the long-term follow up of patients with colorectal cancer. A single-center experience over 13 years.

PURPOSE
To evaluate utility and prognostic value of serum CA 19-9 levels in relation to serum CEA levels in the longterm follow up of patients with colorectal cancer (CRC) METHODS: A total of 315 patients with CRC who were treated over a 13-year period were included in this retrospective study. Data on tumor characteristics, CEA and CA 19-9 levels were recorded. Survival analysis was performed with respect to marker status, while receiver operating characteristics (ROC) curve was plotted to determine the performance of CEA in predicting survival during follow up with calculation of area under curve (AUC) and cut-off value via ROC analysis.


RESULTS
Advanced T stage (T3-4, p<0.001), presence of intramural invasion (p=0.019), lymphatic invasion (p=0.003) and larger tumor volume (p=0.02) were associated only with high CEA levels on admission, while poor histological differentiation (p=0.036) was only associated with high CA 19-9 levels on admission. Presence of normal CEA and CA 19-9 levels was associated with the longest survival time (131.6 and 46.8 months, respectively, p<0.001 for each) and 5-year OS rate of 90.5%, while ROC analysis revealed CEA levels >11 (AUC (95% CI): 0.636 (0.580-0.690), p<0.001) to be a potential marker of poor survival with a sensitivity of 75.0% and specificity of 45.9%.


CONCLUSION
In conclusion, our findings seem to indicate a weaker poor prognostic value of high CA 19-9 levels when used alone and strongly suggest combined use of CEA and CA 19-9 markers in prognostic assessment and risk-adapted follow-up surveillance in CRC patients.


KEY WORDS
CEA, CA 19-9, Colorectal cancer, Prognosis, Survival.