Lab Med Qual Assur.  2020 Dec;42(4):218-223. 10.15263/jlmqa.2020.42.4.218.

Diagnostic Significance of the Ratio of Plasma CYFRA 21-1 Autoantibody Immune Complex to Free CYFRA 21-1 in Patients with Colon Cancer

• Choi HW
• Kim H
• Oh Ac
• Lee JK
• Hong YJ

• KMID: 2510304
• DOI: http://doi.org/10.15263/jlmqa.2020.42.4.218

Abstract

Background
The use of plasma autoantibodies associated with cancer as tumor biomarkers has been studied for several decades. We investigated the diagnostic significance of the ratio of CYFRA 21-1-anti-CYFRA 21-1 autoantibody immune complex (CIC), an autoantibody-binding form of CYFRA 21-1, to free CYFRA 21-1 in patients with colon cancer.
Methods
Overall, 50 patients with colon cancer and 120 healthy control subjects were included. Plasma CIC and CYFRA 21-1 levels were measured using a 9G DNA chip (Biometrix Technology Inc., Korea), and the CIC/CYFRA 21-1 ratios were calculated. Data were compared using the Student t-test or Mann-Whitney U-test. P-values <0.05 were considered to indicate statistical significance. We performed receiver operating characteristic curve analysis to determine the optimal CIC/CYFRA 21-1 cutoff ratio for detecting colon cancer.
Results
The CIC/CYFRA 21-1 ratio was significantly higher in the colon cancer group than in the healthy control group (mean±standard deviation, 1.81±0.75 vs. 1.23±0.37; P<0.001). The optimal cutoff ratio of CIC/CYFRA 21-1 for detecting colon cancer was 1.40 (area under curve [AUC], 0.749; 95% confidence interval, 0.658–0.839; P<0.001), with a sensitivity of 68.0% and specificity of 74.2%. The CIC/CYFRA 21-1 ratio showed higher AUC, sensitivity, and specificity than CYFRA 21-1 or CIC alone.
Conclusions
The plasma CIC/CYFRA 21-1 ratio can be a useful tumor marker in colon cancer.

Keyword

CYFRA 21-1; CIC; Autoantibody immune complex; Colon neo plasms