Prognostic value of Ki-67 in stage I non-small-cell lung cancer: A meta-analysis involving 1931 patients.

There is growing interest in exploring the prognostic value of Ki-67 in non-small-cell lung cancer (NSCLC). However, whether Ki-67 can be regarded as a routine biomarker in clinical practice is still under debate. The present meta-analysis investigated the relationship between Ki-67 and the overall survival (OS) or disease-free survival (DFS) of patients suffering from stage I NSCLC. We searched the Web of Science, Cochrane, and PubMed databases to extract eligible articles. In total, 15 studies involving 1931 patients were included. Pooled hazard ratio (HR) analysis revealed that patients with high Ki-67 labeling index (LI) had poorer OS (HR = 1.95, 95% confidence interval (CI) = 1.43-2.66, P < 0.0001) and DFS (HR = 3.12, 95% CI = 2.17-4.48, P < 0.00001) than those with low Ki-67 LI. In subgroup analysis, high Ki-67 LI was significantly associated with poor prognoses in stage I adenocarcinoma. In future studies, a consensus for the optimal cutoff value for high Ki-67 LI needs to be explored and demonstrated in stage I NSCLC patients.