[S-phase cells of human bladder tumors by in vivo bromodeoxyuridine labeling]

At the time of operation, 10 patients with bladder tumors were given an intravenous infusion of bromodeoxyuridine (BrdU, 250 mg) to label the cells in the DNA synthesis phase (S-phase). The removed tumor specimens were stained immunohistologically using anti-BrdU monoclonal antibody. The percentage of BrdU-labeled cells (S-phase cells) were calculated for each specimen, and expressed as Labeling Index (LI). The average LI of G1, G2 and G3 tumors were 0.9%, 2.3% and 11.9%, respectively. LI was almost parallel to pathological grade. In cases of G2 tumor, LI was varied from 0.2 to 6.2%. The higher LI, the more invasive was the tumor. The patient with the highest LI (12.2%) showed lung metastasis postoperatively and died 6 months after operation. S-phase cells were scattered along the basal layer in G1 papillary tumors, and were observed also near the superficial layer in G2 tumors. In cases of non-papillary tumors, S-phase cells were observed irregularly in various layers. This method will give us useful information on evaluation for malignancy and cell kinetics of bladder tumor.