title: False-positive elevations of carcinoembryonic antigen in patients with a history of resected colorectal cancer.
abstract: Routine monitoring of carcinoembryonic antigen (CEA) levels is standard in patients with resected colorectal cancer (CRC). The incidence of false-positives and the upper limits of false-positive elevations have not been previously well characterized. A search of medical records at Memorial Sloan-Kettering Cancer Center identified 728 patients who underwent an R0 resection of locoregional CRC between January 2003 and December 2012 and who had an increase in CEA level above the normal range after a normal perioperative CEA level. Of these, 358 had a false-positive elevation of CEA level, 335 had a true-positive elevation indicative of recurrent CRC, and 35 had a true-positive elevation indicative of the development of a new, non-CRC malignancy. Of those with false elevations, 111 had a single isolated CEA level elevation (median highest CEA level of 5.5 ng/mL) with no further abnormal measurements, whereas 247 had elevations on 2 or more readings, with a median highest level of 6.7 ng/mL. Of these 247 patients with confirmed false-positive CEA level elevations, only 5 (2%) had measurements greater than 15 ng/mL, and no confirmed elevation greater than 35 ng/mL was a false-positive. False-positive CEA test results in the range of 5 to 15 ng/mL are common. Confirmation of CEA elevation in this range before initiating imaging studies may be appropriate. False-positive results greater than 15 ng/mL are rare, and all confirmed CEA levels greater than 35 ng/mL were associated with cancer recurrence.
authors.affiliation: From the Gastrointestinal Oncology Service, Department of Medicine, Department of Surgery, and Department of Laboratory Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Anya
authors.initials: A
authors.lastname: Litvak
authors.affiliation: From the Gastrointestinal Oncology Service, Department of Medicine, Department of Surgery, and Department of Laboratory Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Andrea
authors.initials: A
authors.lastname: Cercek
authors.affiliation: From the Gastrointestinal Oncology Service, Department of Medicine, Department of Surgery, and Department of Laboratory Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Neil
authors.initials: N
authors.lastname: Segal
authors.affiliation: From the Gastrointestinal Oncology Service, Department of Medicine, Department of Surgery, and Department of Laboratory Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Diane
authors.initials: D
authors.lastname: Reidy-Lagunes
authors.affiliation: From the Gastrointestinal Oncology Service, Department of Medicine, Department of Surgery, and Department of Laboratory Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Zsofia K
authors.initials: ZK
authors.lastname: Stadler
authors.affiliation: From the Gastrointestinal Oncology Service, Department of Medicine, Department of Surgery, and Department of Laboratory Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Rona D
authors.initials: RD
authors.lastname: Yaeger
authors.affiliation: From the Gastrointestinal Oncology Service, Department of Medicine, Department of Surgery, and Department of Laboratory Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Nancy E
authors.initials: NE
authors.lastname: Kemeny
authors.affiliation: From the Gastrointestinal Oncology Service, Department of Medicine, Department of Surgery, and Department of Laboratory Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Martin R
authors.initials: MR
authors.lastname: Weiser
authors.affiliation: From the Gastrointestinal Oncology Service, Department of Medicine, Department of Surgery, and Department of Laboratory Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Melissa S
authors.initials: MS
authors.lastname: Pessin
authors.affiliation: From the Gastrointestinal Oncology Service, Department of Medicine, Department of Surgery, and Department of Laboratory Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Leonard
authors.initials: L
authors.lastname: Saltz
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood; D002272:Carcinoembryonic Antigen / Q000097:blood*; D015179:Colorectal Neoplasms / Q000097:blood* / Q000473:pathology / Q000601:surgery; D005189:False Positive Reactions; D006801:Humans; D009364:Neoplasm Recurrence, Local / Q000097:blood* / Q000473:pathology / Q000601:surgery; D009367:Neoplasm Staging; D011379:Prognosis
chemical_list: D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen