Preoperative serum carbohydrate antigen 242 is a useful predictive and prognostic marker in colorectal cancer.

Background/Aims: Tumor markers (TM) play an important role in the management of colorectal cancer (CRC). This study evaluates the predictive and prognostic value of preoperative serum carbohydrate antigen 242 (CA242) in CRC. Methodology: Preoperative serum CA242 level was detected by C12 protein-chip diagnostic system in 185 CRC patients, and the predictive value of CA242 in stage, lymph node metastasis and tumor invasion depth was assessed. The prognostic value of CA242 for 5-year overall survival (OS) was analyzed. Results: CA242 positive rate elevated with stage advancing, lymph node metastasis and tumor invasion depth, the differences between stage III+IV and stage I+II, between positive lymph node and negative lymph node, between T3+T4 and T1+T2, reached statistical significance (all p<0.05). Receiver operating characteristic analysis demonstrated that the area under the curve of CA242 in stage, lymph node metastasis and tumor invasion depth were 0.677, 0.631 and 0.744, respectively. Patients with higher CA242 had worse 5-year OS compared to those with normal CA242 (p=0.0002). Multivariate analysis showed stage (p=0.000) and preoperative serum CA242 (p=0.026) as independent prognostic factors for 5-year OS of CRC patients. Conclusions: The preoperative serum CA242 can predict stage, lymph node metastasis and tumor invasion depth, and can be used as an independent prognostic factor for OS of CRC.