Prognostic utility of Ki-67 in gastric carcinoma

Abstract

Introduction: Gastric carcinoma represents the third leading cause of cancer related mortality worldwide. Most of cases are diagnosed at the time of tumor metastasis. There is a discrepancy in the results regarding the role of Ki-67 proliferation index as a prognostic factor in gastric carcinoma. Objectives: To assess the prognostic value of Ki-67 proliferation index and correlate Ki-67 expression with the overall survival (OS) in patients with gastric carcinoma. Patients and Methods: This retrospective study included fifty cases collected randomly from archival paraffin blocks of gastric carcinoma. Cases were collected during the period from 2013 to 2018. Sections were prepared and the slides were immunohistochemically stained with Ki-67 antibody. Results: This study showed a statistically significant correlation between higher percentage of Ki-67 expression and cases with tumors located in the fundus and body of the stomach and with distant metastasis. Also a statistically significant correlation between higher mean of Ki-67 positive cell % and cases of adenocarcinoma with pT1 tumors and with loco-regional recurrence (P < 0.001, P=0.02). A higher percentage of Ki-67 expression was found in cases of adenocarcinoma grade III and cases with positive perineural invasion compared to other cases, yet the correlation was statistically insignificant. According to survival analysis, OS rate was 34.0% and the median OS time was 14.6 months. There was no statistically significant association between Ki-67 proliferation index and disease free survival (DFS) and OS. Conclusion: Ki-67 proliferation index can be used as a predictor for distant metastasis and loco-regional recurrence of gastric cancer.