High Ki67 Expression has Prognostic Value in Surgically-Resected T3 Gastric Adenocarcinoma.

Antigen KI-67 (Ki67) plays a critical role in regulation of cell proliferation and has prognostic value in several types of cancer; however, the relationship between Ki67 expression and prognosis in resected T3 gastric adenocarcinoma (GA) has not yet been investigated.Retrospective analysis of 693 patients with T3 GA who underwent surgical resection at a single institution between July 2003 and December 2009 was performed. Ki67 expression in tumor tissues was examined using immunohistochemistry (IHC); the associations between Ki67 and prognosis/survival outcomes were assessed using the Chi-square test, Kaplan-Meier survival analysis, log-rank test, and univariate and multivariate analysis.High Ki67 expression (IHC score > or = 3+) was observed in 335/693 (48.34%) of cases. Ki67 expression was significantly associated with distant metastasis, 5-year median recurrence-free survival time in months (MRFST), and 5-year median overall survival time in months (MOST). Median recurrence and overall survival were 20 and 28 months. High Ki67 expression was associated with shorter MRFST (13 vs. 27 months, p < 0.001) and MOST (21 vs. 35 months, p < 0.001 compared to low K67 expression). Multivariate analysis demonstrated that high K167 expression was an independent prognostic factor for an increased risk of recurrence (p = 0.001) and distant metastasis (p = 0.003) and poorer overall survival (p = 5.33 x 10(-5)).High Ki67 expression was frequently observed in resected T3 GA and was a significant prognostic factor for poor outcome with respect to recurrence, distant metastasis and overall survival. Ki67 may represent a useful prognostic biomarker for resected T3 GA.