Proliferative activity in advanced gastric-cancer with ki-67 and propidium iodide - analysis by flow-cytometry.

By setting the cut-off line at the level as used in a negative control study without primary antibody in the same sample, the Ki-67 labeling rate was calculated by the Ki67-DNA dual fluorescence analysis. The mean Ki-67 labeling rate of 28 advanced gastric cancer was 45.1% (13.9-76.3%). The Ki-67 labeling rates were significantly higher for larger size tumor (p<0.05), peritoneal metastasis and advanced stage (p<0.01). This is the first report that cycling cells are calculated by setting the cut-off line for solid tumors. Use of this flow cytometric procedure substantially facilitates the quantification of proliferating cells in gastric cancer.