Role of Surface Plasmon Resonance Assay on Detection of Serum Tumor Marker CEA in Lung Cancer

Objective To develop a new method： surface plasmon resonance (SPR) technique for the detection of serum carcinoembryonic antigen (CEA) and compare the effects of SPR and electro-chemiluminescense immunoassay (ECLIA) on lung cancer diagnosis. Methods The reaction system of SPR was established and the degree of precision of SPR assay was assessed.The serum CEA levels were detected with both SPR assay and ECLIA in 120 samples from patients with lung cancer (n=40)，non-lung cancer (n=40)，and the healthy controls (n=40).The data were analyzed with statistical software SPSS. Results Variability intergroup and intragroup of SPR was 6.7% and 7.7%，respectively.Mean serum CEA level in lung cancer group （SPR 33.12±28.66 μg/L，ECLIA 41.10±30.67 μg/L)was significantly higher than that in control group(SPR 1.12±0.87 μg/L，ECLIA 1.52±1.46 μg/L)，(P<0.01)，but there was no difference of the positive rate of lung cancer diagnosis between SPR and ECLIA (P>0.05).The positive rate of lung cancer diagnosis was similar to that of non-lung cancer diagnosis，either by SPR or ECLIA (P>0.05).The sensitivities，specificities，accuracies，positive predictive rates and negative predictive rates between SPA and ELCIA were also similar(62.5％ vs.57.5％，70．0％ vs.72.5％，67.5％ vs.67.5％，51.0％ vs.51.1％，84.2％ vs.82.4％，P>0.05).The mean work time for detection serum CEA with SPA was significantly shorter than that with ECLIA (3.0±0.6min vs. 29.1±6.8min，P<0.01). Conclusion SPR is a good assay for detection of the serum CEA leve1 of lung cancer which has the advantages of sensitivity，reliability，fastness and low cost．This method may further be developed for clinical application.