Carcinoembryonic antigens were useful prognostic factors in CRC.13 Compared to solitary CRC, abnormal CEA was more commonly seen in patients with SCRC.14 Preoperative CEA positivity was a significant predictor of SA for SCRC patients (P = .047) but was not associated with metachronous lesions (P = .187, .302, respectively). This evidence concerns the gene CEACAM5 and colorectal carcinoma.