Background: This meta-analysis aimed to elucidate the prognostic role of the Ki-67 labeling index (LI) in gastric cancer (GC).
Methods: The current study included 3,615 GC patients in 20 eligible studies, and evaluated the prognostic role of Ki-67 LI in GC. Subgroup analysis was conducted based on depth of invasion and cutoff value for high Ki-67 LI.
Results: A high Ki-67 LI correlated significantly with worse survival (hazard ratio [HR] = 1.214, 95% confidence interval [CI], 1.004-1.468). However, there was no significant correlation between high Ki-67 LI and worse survival in advanced GC (HR = 1.252, 95% CI, 0.801-1.956). The subgroup with cutoff value ≤25% showed a significant correlation with worse survival, but this was not seen in the subgroup with cutoff >25% (HR = 1.433, 95% CI, 1.094-1.876 vs. HR = 1.005, 95% CI, 0.801-1.262). In addition, in the 10% <Ki-67 LI ≤ 20% range, there was a significant correlation between high Ki-67 LI and worse overall survival (HR = 1.931, 95% CI, 1.013-3.310).
Conclusions: A high Ki-67 LI correlated significantly with a worse prognosis in GC patients. Further cumulative studies for the optimal cutoff value for high Ki-67 LI are needed before application in clinical practice.