The validity of carcinoembryonic antigen as a surveillance marker according to the pattern of recurrence in colorectal cancer
Background Even though the validity of the carcinoembryonic antigen (CEA) test has been shown for monitoring colorectal cancer recurrence after surgery, it has been applied without specification to the site of recurrence. In the present study, we aimed to verify the validity of CEA as a site-specific surveillance tool in colorectal cancer after curative resection by analyzing the sensitivity of CEA according to the pattern of recurrence. Methods A total of 722 patients diagnosed with recurrent
... sed with recurrent colorectal cancer after curative resections were enrolled, and their medical records were reviewed. Using a cutoff CEA value of 5 ng/ml at the time of detection, the sensitivity of the CEA test according to the pattern of recurrence (locoregional or systemic recurrence) and detailed information about the location of the recurrence sites were investigated. Results In patients with recurrence in the peritoneum, combined sites, and the liver, the sensitivities of CEA test were 59.4%, 51.3%, and 44.8%, respectively. These values were higher than those in the para-aortic lymph nodes, lungs, and the brain, with sensitivities of 30.4%, 23.6%, and 16.7%, respectively. In the subset analysis, the CEA test sensitivities for patients with recurrence in the peritoneum, liver, and para-aortic lymph nodes were 61.9%, 53.2%, and 22.2% in colon cancer and 54.5%, 36.0%, and 35.7% in rectal cancer, respectively. Conclusions Postoperative surveillance CEA levels may have different values according to the site of recurrence. Therefore, a follow-up strategy considering site-specific CEA sensitivity after surgery could improve early detection of recurrent colorectal cancer.