Background: The KIF5B-RET  fusion gene is a novel oncogene that has been observed in a subset of lung cancers in recent years. However, the results of related epidemiological studies remain unclear. Thus, a meta-analysis was conducted to evaluate the correlation of KIF5B-RET  expression based on RT-PCR detection with clinicopathological features and prognosis of lung cancer.
Methods: The PubMed, Google Scholar, Wiley Online, SpringerLink and Chinese National Knowledge Infrastructure databases were searched to identify the eligible studies. The association of the occurrence of KIF5B-RET  fusion gene in lung cancer with age, gender, smoking status, histology type, differentiation and TNM stage was analyzed. HR, overall survival (OS) and progression-free survival (PFS) were used to describe the prognosis of patients with lung cancer. The OR and 95% CI were calculated to assess the correlations. Random- and fixed-effects models were used to analyze the data.
Results: A total of 13 studies, which included 8,859 lung cancer patients, were included in the study based on the inclusion criteria. A total of 121 patients with positive KIF5B-RET  fusion gene status were detected, with a positive expression rate of 1.36%. KIF5B-RET  fusion gene status was identified at significantly higher frequencies in female (OR=0.67, 95% CI=0.48–0.94) than male patients, and the same trend was found in young (<60 years) patients (OR=0.08, 95% CI=0.01–0.45) compared with old patients (≥60 years). No differences were found in the TNM stage, histology, differentiation and smoking. Based on the prognosis, no difference was found between the status of the positive and negative KIF5B-RET  fusion genes in OS and PFS of patients. 
Conclusion: The KIF5B-RET  fusion gene occurred predominantly in young female patients with lung cancer. However, the relationship between the expression of the fusion gene and the prognosis of lung patients remains unclear.
Keywords: pathological parameters, KIF5B-RET, lung cancer, fusion gene