MicroRNA‐21 was a promising biomarker for lung carcinoma diagnosis: An update meta‐analysis

OBJECTIVE: To investigate the diagnostic performance of microRNA‐21 detected in serum or sputum as a biomarker for lung carcinoma identification through pooling the open published data. METHODS: Clinical diagnostic studies related to microRNA‐21 as a biomarker for lung carcinoma identification were electronically searched in the databases of Pubmed, EMBASE, Cochrane Library, Chinese National Knowledge Infrastructure, Wanfang, and Google Scholar. The data of the included studies was extracted and made pooling of diagnostic sensitivity, specificity, diagnostic odds ratio (DOR), area under the summary receiver operating characteristic curve (ROC) (AUC) for microRNA‐21 expression in serum or sputum as a biomarker for lung carcinoma identification. The publication bias was evaluated by Deek's funnel plot. RESULTS: Seventeen diagnostic studies were finally included and made data pooling. For the included 17 studies, 4 investigated the microRNA‐21 expression in sputum and 13 studies in serum. The pooled diagnostic sensitivity and specificity were 0.73 (95% CI, 0.67–0.78) and 0.81 (95% CI, 0.75–0.85), respectively, under random effect model. The combined DOR was 9.65 (95% CI, 6.64–14.03) with the AUC of 0.84 (95% CI, 0.80–0.87). Given a pre‐test probability of 50%, the post‐test positive probability and post‐test negative probability were 79% and 25%, respectively, by using microRNA‐21 as a biomarker for lung carcinoma diagnosis. Deek's funnel was obviously asymmetry and indicated significant publication bias (p < 0.05). CONCLUSION: MicroRNA‐21 in serum or sputum was a promising biomarker for lung cancer identification with relative high diagnostic sensitivity and specificity.