Carcinoembryonic antigen assay: an adjunct to liver scanning in hepatic metastases detection

The radionuclide liver scan is a valuable study for detection of hepatic metastases; however, it has a false-negative rate of between 10 and 30%. In a double-blind study involving 377 patients, we assessed the value of CEA assay as an adjunct to liver scanning for detection of hepatic metastases. Fifty-seven patients studied by both methods were ultimately proven to have liver metastases. All patients with CEA levels above 9 ng/ml and focal defects on liver scan had hepatic tumor involvement, while only 4 of 291 patients with CEA values less than 9 ng/ml and negative scans were later shown to have liver metastases. CEA and liver scan results were discordant for 29 patients with proven hepatic metastases: the radionuclide study was positive in 21 cases with false-negative CEA results, while the CEA assay suggested the presence of metastatic disease in eight of the 12 patients with false-negative liver scans.