Carbohydrate antigen 242 highly consists with carbohydrate antigen 19-9 in diagnosis and prognosis of colorectal cancer: study on 185 cases.

The objective of the study was to compare the clinical value of preoperative serum carbohydrate antigen 19-9 (CA19-9) and carbohydrate antigen 242 (CA242) in diagnosis and prognosis for 5-year recurrence-free survival (RFS) in patients with colorectal cancer (CRC). Preoperative serum CA19-9 and CA242 concentrations were detected by C12 protein chip diagnostic system in 185 patients with CRC, and informative data were collected during 5-year follow-up periods. The value of CA19-9 and CA242 in diagnosis and prognosis for 5-year RFS as well as their consistencies and correlations were comparatively analyzed. The sensitivities of CA19-9 and CA242 were only 19.5 and 20%, respectively; the efficiencies of two TMs were 53.9 and 54.2%, respectively; and two TMs increased significantly with advancing clinical stages (P < 0.0001). Preoperative CA19-9 and CA242 levels correlated with stage (r, 0.411 and 0.408) and CEA concentration (r, 0.553 and 0.630). The concentrations of two TMs closely correlated with each other (r = 0.829), and two TMs had a very strong consistency in diagnosis (κ = 0.931). Among 88 of 185 cases with complete follow-up information on RFS, patients with positive preoperative serum CA19-9 or CA242 had higher 5-year recurrent rates (72.2% vs. 44.3%, P = 0.034; 76.5% vs. 43.7%, P = 0.015) and reduced median RFS (14 vs. 36 months, 12 vs. 36 months) compared with those with negative TMs. The consistency of predicting prognosis for RFS of two TMs was extremely strong (κ = 0.964). ROC curves analysis showed that CA242 test performed better than CA19-9 test (AUC, 0.648 vs. 0.605). Univariate analysis showed that preoperative serum status of both TMs was correlated with 5-year RFS (P < 0.05), whereas multivariate Cox regression model analysis revealed that none of them were independent prognostic factors for RFS. Both CA19-9 and CA242 had strong consistencies in diagnosis and prognosis for predicting 5-year RFS. CA242 demonstrated superior value to CA19-9 in CRC.