Can We Detect Lung Cancer Earlier by Measurement of Serum C-Reactive Protein, Carcinoembryonic Antigen, and Cell-Free Plasma DNA?

Abstract

BackgroundSeveral studies reported C-reactive protein (CRP) levels were increased in patients with lung cancer. Carcinoembryonic antigen (CEA) is a known tumor marker increased in lung cancer. Cell-free DNA is present in increased amounts in the plasma of patients with cancer. We performed this study to evaluate the role of CRP, CEA, and cell-free plasma DNA for the detection of lung cancer. Patients and MethodsCRP, CEA, and cell-free DNA were measured in plasma samples from 41 patients with lung cancer and 62 healthy controls. The cell-free DNA was determined in plasma with real-time quantitative polymerase chain reaction. The diagnostic accuracy of each assay was calculated using receiver operating characteristic curve. ResultsCRP and CEA were significantly increased in patients with lung cancer than in healthy controls (both P < .05). However, the concentration of cell-free DNA was not statistically significantly increased in patients with lung cancer than in controls (P = .09). The area under the curve (AUC) of CRP was 0.83 (95% CI, 0.739–0.894), and the AUC of CEA was 0.82 (95% CI, 0.727–0.885). ConclusionCRP and CEA might be useful biomarkers that allow selection of those cases requiring a more intensive screening test of lung cancer. Further studies need to be performed to confirm these findings.