Ki-67 antigen expression in relation to clinicopathological variables and prognosis in gastric cancer

One hundred and thirty surgical specimens of gastric adenocarcinoma were obtained from patients who had undergone radical gastrectomy. The samples were formalin-fixed, paraffin-embedded and used for immunostaining of Ki-67 antigen. Mean Ki-67 index was 41.8% (SD 15. 7%, range 8.2-84.2%). Differentiated carcinomas had a higher Ki-67 index than undifferentiated tumors, although other clinicopathological variables, including lymph node metastasis and depth of invasion showed no correlation with Ki-67 index. In the undifferentiated tumors, Ki-67 index correlated with lymph node involvement. A high Ki-67 index ( 55%) was found to be an independent indicator of poor prognosis in patients with undifferentiated tumors.