Objective To investigate the expression of serum microRNA-23a (miR-23a) and carcinoembryonic antigen (CEA) in patients with colorectal cancer and their relationships with clinical characteristics and prognosis.

Methods A total of 200 patients with colorectal cancer were retrospectively selected as observation group, and 50 healthy volunteers who underwent physical examinations during the same period were selected as control group. The serum levels of miR-23a and CEA in the two groups were compared, and the serum levels of miR-23a and CEA in colorectal cancer patients with different clinical characteristics were also compared. According to the follow-up outcomes, 112 patients with recurrence or death were classified into poor-prognosis group, and 88 patients without recurrence were classified into good-prognosis group. Receiver operating characteristic (ROC) curves were plotted to analyze the predictive efficacy of serum miR-23a and CEA alone and their combination for the prognosis of patients with colorectal cancer.

Results The serum expression levels of miR-23a and CEA in the observation group were higher than those in the control group, and the differences were statistically significant (P < 0.05). There were statistically significant differences in the serum miR-23a expression levels among patients with different degrees of differentiation, TNM stages, and lymph node metastasis status (P < 0.05). There were statistically significant differences in the serum CEA levels among patients with different ages, degrees of differentiation, TNM stages, lymph node metastasis status, tumor diameters, and depths of invasion (P < 0.05). Compared with the good-prognosis group, the poor-prognosis group had higher serum expression levels of miR-23a and CEA, and the differences were statistically significant (P < 0.05). The ROC curves showed that the sensitivity, specificity, and area under the curve of miR-23a and CEA in combination for predicting the prognosis of patients with colorectal cancer were 86.63%, 85.31%, and 0.812, respectively, and the predictive efficacy was higher than that of either indicat or alone.

Conclusion The serum expression levels of miR-23a and CEA in patients with colorectal cancer are significantly increased, and their abnormal expressions are closely related to the clinical pathological characteristics of the patients. The expression of miR-23a and CEA has certain predictive value for the prognosis of patients with colorectal cancer, and the predictive value of combined detection is higher.