Prognostic value of urokinase-type plasminogen activators in gastric-cancer

To elucidate the relation between urokinase-type plasminogen activator (U-PA) and metastasis in gastric cancer, we examined U-PA tissue status immunohistochemically. Ninety-eight primary gastric cancer, prepared by AMeX method, were analyzed with anti-U-PA and anti-proliferating cell nuclear antigen (PCNA) monoclonal antibody. In addition, DNA ploidy patterns were determined by cytofluorometer after staining with propidium iodide. U-PA immunoreactivity can be observed as diffuse cytoplasmic staining, as intensely outlined luminal borders or in desquameted cells in the lumens. U-PA expression-positive tumors showed higher incidence of serosal invasion, lymph node involvement or larger tumors than did U-PA negative ones. There was no correlation between U-PA tissue status and PCNA labeling rates or DNA ploidy patterns. Patients with a U-PA positive tumor survived significantly shorter than those with U-PA negative ones. These results may indicate that U-PA tissue status is a useful biological prognostic indicator in gastric cancer. The high malignant potential of U-PA positive tumors may be associated with a rapid infiltrating capacity through gastric wall but not with a high proliferative activity.