To evaluate the clinical value of SAA by detecting their expression levels in patients with lung cancer and the analysis of the relativity of SAA for early diagnosis.

There are 243 cases specimens obtained from lung cancer patients who were newly diagnosed and without any treatment in Zhejiang Cancer Hospital from April 2014 to June 2015. The 243 lung cancer individuals were 147 male, and 96 female, their ages ranged from 29 to 85 years, with an average age of 63 years.The distribution of pathological type was as follows: 95 patients were adenocarcinoma, 102 patients were squamous carcinoma, and 46 patients were small cell carcinoma. The distribution of TNM staging systems was as follows: 59 patients in stage 1and stage 2, 54 patients in stage 3, and 130 patients in stage 4.While 179 cases physical examination as the control. There were 94 individuals male, and 85 individuals female. Their ages ranged from 26 to 86 years, with an average age of 61 years. By using latex enhanced immune turbidimetric method, serum SAA concentrations in patients with lung cancer and healthy controls were checked on the Hitachi-7600 automated chemistry analyzer (Hitachi). The comparisons of all analyses values between healthy controls and lung cancer were estimated by two independent samples nonparametric tests (Mann-Whitney U). The association between SAA and lung cancer prognostic factors such as age, smoking status and metastasis, was evaluated by spearman correlation and multivariate analysis.

The median and interquartile spacing of SAA concentration was 42.36 mg/L (9.35, 74.22) in lung cancer patients .While in healthy control was 11.24 mg/L (3.25, 21.45). The median level of SAA in lung cancer patients (42.36 mg/L) were significantly higher than in healthy controls (11.24 mg/L), and difference reached statistically significant (Z=-2.403, P=0.006). Nevertheless, there was no significant difference in SAA concentrations among the different pathological types(Z=-1.013, P=0.339), ages (Z=0.578, P=0.458) and gender(Z=0.726, P=0.246) of lung cancer patients. While the level of SAA in has smoking status (Z=-2.282, P=0.013) and distant metastasis (Z=-2.138, P=0.017) of lung cancer was higher.By drawing ROC curve, the cut off value of SAA in distinguishing lung cancer with healthy control was 14.48 mg/L. Meanwhile, the AUC was 0.811, the accuracy is 89.12% and the sensitivity was 88.73%.Serum concentration was positively related with smoking status (r= 0.331, P=0.018) and distant metastasis (r=0.372, P=0.015) by Spearman correlation analysis.

Serum SAA concentrations may contribute to the auxiliary diagnosis of lung cancer, evaluate the clinical stage and distant metastases of lung cancer.(Chin J Lab Med, 2016, 39: 220-224)

Serum amyloid A protein; Lung neoplasms; Diagnosis; Risk assessment