Wei DM, et al. - Via this meta-analysis, researchers determined in lung cancer patients the predictive ability of Ki-67 as assessed in eligible studies (108 studies in 95 articles with 14,732 patients). According to the pooled hazard ratio (HR), a high Ki-67 level could serve as a valuable predictive factor for lung cancer. A significant association of a high Ki-67 level with age, gender and smoking status was also reported. Ki-67 overexpression had significant positive correlations with poorer differentiation, larger tumor size, and higher pathologic stages. For lymph node metastasis positive and advanced TNM stages, a valuable predictive factor was high expression of Ki-67.