title: Clinical Usefulness of Serum CYFRA 21-1 in Patients with Colorectal Cancer.
abstract: OBJECTIVE
  Among diverse tumor markers, pretreatment evaluation and follow-up detection of recurrence in colorectal cancer are generally evaluated by serum carcinoembryonic antigen (CEA) levels. However, there have been some reports about the low accuracy and high false-positive results of CEA in colorectal cancer. We investigated the clinical utilities of CYFRA 21-1 by comparing CEA and cancer antigen 19-9 (CA 19-9) in pretreatment and recurrent colorectal cancer.
  
  
  METHODS
  Using a solid-phase immunoradiometric assay, serum levels of CYFRA 21-1, CEA and CA 19-9 were analyzed in 132 patients with primary colorectal cancer, 124 healthy controls, 104 patients with benign colorectal disease and 19 patients with recurrent colorectal cancer. We determined three different cutoff values to evaluate the sensitivity of diagnostic performance in pretreatment and recurrent colorectal cancer.
  
  
  RESULTS
  CYFRA 21-1 (≥ 1.13 ng/ml) had a sensitivity of 47 %, compared with 37 % for CEA (≥ 3.05 ng/ml) and 32.6 % for CA 19-9 (≥ 23.1 ng/ml) in the initial staging of primary colorectal cancer. Using different cutoff values, CYFRA 21-1 showed higher sensitivity for pretreatment colorectal cancer than CEA and CA 19-9 in adenocarcinoma and adenosquamous carcinoma of this study. A mildly significant correlative relationship was noted between Dukes' stages and three tumor markers (p < 0.01). The areas under the receiver operating characteristic curves of CYFRA 21-1, CEA and CA 19-9 were 0.81 ± 0.03, 0.74 ± 0.03 and 0.62 ± 0.04, respectively, for discriminating colorectal cancer patients from patients with benign colorectal disease. In addition, CYFRA 21-1 was determined as the most sensitive tumor marker for evaluating recurrent colorectal cancer for all cutoff values.
  
  
  CONCLUSIONS
  This study showed that CYFRA 21-1 could be a useful and dependable tumor marker for pretreatment and recurrent colorectal cancer. Further prospective studies on its usefulness with respect to the prognosis and utility of combined tumor markers are needed.
authors.affiliation: Department of Nuclear Medicine, Dankook University Medical College, Dongnam-ku, Anseo-dong, Cheonan, 330-715 Republic of Korea.
authors.forename: Jai Hyuen
authors.initials: JH
authors.lastname: Lee
keywords: CEA and CA 19–9; CYFRA 21–1; Colorectal cancer