Increased serum amyloid A as potential diagnostic marker for lung cancer: a meta-analysis based on nine studies

BACKGROUND: Previous studies have disclosed that serum amyloid A (SAA) is likely involved in the lung cancer pathogenesis and progression. We performed a systematic evaluation and meta-analysis to disclose the correlation between the expression of SAA and lung cancer and to evaluate its value for lung cancer diagnosis. METHODS: We searched the relevant articles from the databases of Medline, Embase, Cochrance Library and Web of Science and calculated the standardized mean difference (SMD) with 95 % confidence interval (CI) to assess the expression difference of SAA between lung cancer and normal patients. Moreover, we counted the positive rate, sensitivity and specificity and drew a summary receiver operating characteristic curve (SROC) to evaluate the diagnostic value of SAA for lung cancer. RESULTS: A total of nine studies with 1392 individuals were included in this analysis. The results showed an increased SAA was correlated with the incidence of lung cancer (P < 0.001), especially with the lung squamous cell carcinoma (LSCC) (p = 0.012). The overall sensitivity and specificity of SAA for discerning lung cancer was 0.59 (95 % CI: 0.54–0.63) and 0.92 (95 % CI: 0.88–0.95), respectively. The area under the SROC curve was 0.9066 (SE = 0.0437). CONCLUSIONS: Increased SAA in lung cancer was intimately correlated with the development and progression of lung cancer. A higher specificity of SAA suggested that it should be a significant biomarker for discerning lung cancer from normal individuals, especially for LSCC (p = 0.012).