Clinical value of CEA in patients with lung adenocarcinoma and its relationship with epidermal growth fac-tor receptor mutations

LV Yanling; YUAN Dongmei; SONG Yong; JIN Shuxian

Abstract：Objective To determine the expression of carcino embryonie antigen( CEA) in serum and pleural effusion in pa-tients with lung adenocarcinoma and its relationship with epidermal growth factor receptor( EGFR) mutations. Methods Seventy-nine serum and pleural effusion samples were collected from 79 lung adenocarcinoma patients with malignant pleural effusion. The concentra-tion of CEA was detected by immunoradiometric assay, and the relationship between the level of CEA and EGFR mutations was ana-lyzed. Results A total of 35 cases involved EGFR mutations, and the mutation rate of EGFR was 44. 3%(35/79). For the serum CEA, the area under curve( AUC) was 0. 661( 95%CI:0. 536-0. 785) . When the cut-off value was 19. 5 ng/ml, the efficacy of sensi-tivity and specificity were best. For the pleural effusion CEA, when the cut-off value was 55. 5 ng/ml, the AUC was 0. 757( 95%CI:0. 653-0. 862) . The mutation rate was significantly higher in the patients with high serum(≥19. 5 ng/ml) and pleural effusion(≥55. 5 ng/ml)levels of CEA than those with low expression levels(P<0. 05). Moreover, the positive rates of EGFR mutations of the three groups( both≥cut-off, any of them≥cut-off and both<cut-off) were 64. 3%, 60. 0%,16. 1%, respectively( P<0. 001) . In a multivari-ate regression analysis, the level of pleural effusion CEA( HR:1. 002, 95% CI:1. 001-1. 004, P=0. 003) was confirmed as independ-ent factor of predicting EGFR mutations. Conclusion CEA can probably serve as a marker of predicting EGFR mutations.