Abstract: Objective To investigate the predictive value of plasma four and a half LIM domains protein 2 (FHL2),pulmonary surfactant-associated glycoprotein A1 (SFTPA1),and solute carrier family 31 member 1 (SLC31A1) for diagnosis and prognosis of lung cancer.Methods From January 2018 to June 2022,96 lung cancer patients treated in our hospital were included as the lung cancer group.Another 108 patients with benign lung diseases and 120 healthy subjects who underwent physical examinations were regarded as the benign lesion group and control group,respectively.QRT-PCR was applied to detect the expression level of FHL2.ELISA was applied to detect SFTPA1 and SLC31A1 levels.ROC curve was applied to analyze the diagnostic value of FHL2,SFTPA1,and SLC31A1 for lung cancer.Kaplan-Meier method was applied for survival analysis.COX regression was applied to analyze the influencing factors of poor prognosis in lung cancer patients.Results The levels of FHL2 and SLC31A1 gradually decreased in the control group,benign lesion group,and lung cancer group,while the level of SFTPA1 gradually increased (P＜0.05).The Area Under the Curve (AUC) of the combined diagnosis of lung cancer by was 0.940,which was better than their individual diagnoses (all P＜0.05).The expression of FHL2,SFTPA1,and SLC31A1 was correlated with TNM staging,distant metastasis,and differentiation degree (P＜0.05).The 2 year cumulative survival rates of FHL2 and SLC31A1 high expression groups were 92.31% and 89.09%,respectively,which were higher than those of the low expression groups (63.64% and 65.85%).The 2 year cumulative survival rate of SFTPA1 high expression group was 67.39%,which was lower than that of the low expression group (90.00%) (both P＜0.05).TNM staging,distant metastasis,and levels of FHL2,SFTPA1,and SLC31A1 were influencing factors for mortality in lung cancer patients (P＜0.05).Conclusion The levels of FHL2 and SLC31A1 in the plasma of lung cancer patients are decreased,while SFTPA1 is increased.These three factors have certain value for diagnosis of lung cancer.Low expression of FHL2 and SLC31A1,and high expression of SFTPA1 are influencing factors for mortality of lung cancer patients.

Key words: lung cancer, four and a half LIM domains protein 2, pulmonary surfactant-associated glycoprotein A1, solute carrier family 31 member 1, diagnosis, prognosis