Objective: To explore the clinical significance of expression of CEA mRNA and serum CEA and the related proteins in colorectal cancer (CRC).
Methods: Blood samples were collected from 370 CRC patients and 350 controls. CEA mRNA was determined by RT-PCR and levels of CEA, CA19-9, CA242, and CA724 were examined with chemiluminescence.
Results: The positive rate of jointly detecting serum CEA, CA19-9, CA242, and CA724 was significantly higher than CEA mRNA expressions (P < 0.01), both positive rates were significantly correlated with TNM stage, lymph node, and visceral metastasis. The positive rate of jointly detecting in patients with poorly differentiated tumor was significantly higher than that in patients with highly differentiated tumor (P < 0.01). By contrast, CEA mRNA expression was not related with histopathologic grading. Postoperative follow-up found that all patients with high levels of CEA mRNA and serum CEA and the related proteins had liver, lung, pelvis, or other distant metastases.
Conclusions: These results suggest that high expressions of CEA mRNA and high levels of serum CEA and the related proteins are associated with the incidence and advanced of CRC. In addition, joint detection of serum CEA and the related proteins is more sensitivity than examination of serum CEA mRNA.