BackgroundA novel fusion gene of echinoderm microtubule-associated protein-like 4 (EML4) and anaplastic lymphoma kinase (ALK) has been recently identified in non-small-cell lung cancers (NSCLCs). Patients with the EML4-ALK fusion gene demonstrate unique clinicopathological and physiological characteristics. Here we present a meta-analysis of large-scale studies to evaluate the clinicopathological characteristics of NSCLC patients harboring the EML4-ALK fusion gene.MethodsBoth English and Chinese databases were systematically used to search the materials of the clinicopathological characteristics of patients with NSCLC harboring the EML4-ALK fusion gene. Pooled relative risk (RR) estimates and the 95% confidence intervals (95% CI) were calculated with the fixed or random effect model. Publication bias and chi-square test were also calculated.Results27 retrospective studies were included in our meta-analysis. These studies included a total of 6950 patients. The incidence rate of EML4-ALK fusion in NSCLC patients was found to be 6.8% (472/6950). The correlation of the EML4-ALK fusion gene and clinicopathological characteristics of NSCLC patients demonstrated a significant difference in smoking status, histological types, stage, and ethnic characteristics. The positive rate of the EML4-ALK fusion gene expression in females were slightly higher than that in males, but not significantly (P = 0.52). In addition, the EML4-ALK fusion gene was mutually exclusive of the EGFR and KRAS mutation genes (P = 0.00).ConclusionOur pooled analysis revealed that the EML4-ALK fusion gene was observed predominantly in adenocarcinoma, non-smoking and NSCLC patients, especially those diagnosed in the advanced clinical stage of NSCLC. Additionally, the EML4-ALK fusion gene was exclusive of the EGFR and KRAS mutation genes. We surmise that IHC assay is a valuable tool for the prescreening of patients with ALK fusion gene in clinical practice, and FISH assay can be performed as a confirmation method. These insights might be helpful in guiding the appropriate molecular target therapy for NSCLC.

Objectives We investigated the association between the consumption of fresh and processed fish and glioma risk using a meta-analysis approach. Methods We selected and analyzed observational studies that discussed the relationships between fresh and processed fish intake on glioma risk from PubMed, Web of Science, Embase, and the SinoMed and Wanfang databases from inception to 31 March 2020. Studies were selected according to pre-established eligibility criteria and data were extracted separately by two researchers. A meta-analysis was conducted based on a random-effects model to provide pooled odds ratios (OR) and 95% confidence intervals (CIs). Results Eight studies considered the relationship between fish intake (seven fresh and seven processed fish) and glioma risk and were included in this meta-analysis. The OR effect size for fresh fish intake and glioma risk was 0.72 (95%CI 0.53–0.97) and the overall OR effect size for processed fish intake and glioma risk was 1.88 (95%CI 1.06–3.34). Conclusion Dietary intake of fresh fish may reduce the risk of glioma, but consumption of processed fish may increase the risk of glioma. This study had some limitations, and further studies are therefore required to clarify the associations between fish intake and glioma risk.