Objective: This study was designed to investigate the efficiency of preoperative serum carcinoembryonic antigen (CEA) and carbohydrate cancer antigen (CA19-9) levels for diagnosing synchronous liver metastases and lymph node in colorectal carcinoma (CRC) patients.
Subjects and methods: A total of 300 patients with histologically diagnosed CRC were included in this study between May 2014 and March 2015. The data were obtained prospectively from patient's medical records: medical history, demographics, tumor location, differentiation (grade), depth of the tumor (T), lymph node metastases (N), distant metastases (M), lymphatics, venous and perineural invasion, and disease stage. Tumor markers were measured with an electrochemiluminescent assay and the reference value was 5ng/ml for CEA and for Ca19-9, 37u/ml.
Results: There was A high statistically significant difference in the levels of serum CEA and CA19-9 between different disease stages of CRC (P<0.001). Regarding different T stages of CRC, We noticed a significant statistical difference in CEA (stage I 3.76±8.73; II 5.68±17.27, III 7.56±14.81, and IV 70.90±253.23) and CA 19-9 levels (stage I 9.65±11.03, II 9.83±11.09; III 19.58±36.91, and IV 228.9±985.38, respectively). The mean CEA and CA19-9 serum levels were significantly higher in patients with regional lymph nodes involvement (CEA 37.21±177.85 vs 4.79±9.90, CA19-9 119.51±687.71 VS 12.24±17.69, respectively, P<0.05) and in liver metastases (CEA 86.56±277.65 vs. 5.98±12.98, and CA19-9 273.27±1073.46 vs. 4.98±3142, respectively, with P<0.001) in comparison to patients without lymph node involvement and liver metastases. We noticed a cut-off value for lymph nodes involvement, for CEA and CA 19-9, 3.5 ng/mL and 7.5 U/mL, respectively. While, a cut-off value for the presence of synchronous liver metastases of these two markers was 3.5ng/mL AND 5.5 U/mL.
Conclusion: Our study showed that tumor makers, CEA and CA19-9, can be used as diagnostic factors regarding the severity of CRC specifically to suggest metastatic disease in CRC.