Systematic review of CYFRA 21-1 as a prognostic indicator and its predictive correlation with clinicopathological features in Non-small Cell Lung Cancer: A meta-analysis

AIM To evaluate the value of Cytokeratin 19 fragment for its survival prognostic indicator and predictive correlation with clinicopathological features in Non-small Cell Lung Cancer. METHODS Eligible studies or databases for articles were retrieved via search systematically. Pooled effect was calculated to evaluate the association between Cytokeratin 19 fragment level and long-term overall survival, as well as the tumor clinicopathological features in Non-small Cell Lung Cancer patients. A fixed-effects or random-effects model was used to calculate the Pooled risk ratios (RRs) and corresponding 95 % confidence intervals (CIs). RESULTS Six studies were up to the selection criteria. This meta-analysis indicated that Cytokeratin 19 fragment high level expression correlated with lower 2-year overall survival (RR =0.47; 95%CI: 0.28-0.79), higher Tumor Node Metastasis stage (II+III+IV) (RR =1.43; 95%CI: 1.15-1.76) in Non-small Cell Lung Cancer. The pooled RR estimates indicated that there is no statistical significance of Cytokeratin 19 fragment level expression in the advanced Non-small Cell Lung Cancer (IIIB+IV) (RR =1.43, 95% CI: 0.85-2.43). CONCLUSION Cytokeratin 19 fragment is a negative prognosis indicator and its high level expression indicates higher Tumor Node Metastasis pathological stage (II+III+IV) in Non-small Cell Lung Cancer. In advanced Non-small Cell Lung Cancer, the level of serum Cytokeratin 19 fragment appears to provide more prognostic information than it does for clinical Tumor Node Metastasis stage information. Further studies are required to confirm our results.