[Studies of biological malignancy in bladder cancer using two parameter DNA-RNA cytofluorometric analysis]

An acridine orange cytofluorometric analysis was used to study the DNA-RNA contents of bladder washing exfoliated cells from 109 patients with transitional cell carcinoma of the urinary bladder. DNA and RNA measurements were performed in each of 200-300 cells/sample, and DNA index (DI) and RNA index (RI) were calculated from the distributions of these values. Presence of aneuploid stem cell line and/or increased mean DNA contents were observed in 83 (76.1%) of the 109 patients. Elevated RNA content in a diploid cell population, was of no additional diagnostic significance. Histologically diagnosed high grade and high stage bladder carcinoma apparently showed an aneuploid stem cell line with high DI and high RI. Thirty patients with superficial bladder cancer (Ta and Tl) who had tumor recurrence within 2 years after surgical interventions showed a significantly increased RI in contrast to 10 patients who had no recurrence for more than 2 years. RNA content measurement was thought to be useful for prediction of tumor recurrence after surgical interventions. Six patients who had a progression from superficial to invasive carcinoma were with high histological malignancy, lamina propria invasion, high DI and high RI. However, there was no significant difference in RI between the 6 patients and the other patients with superficial bladder cancer. Eight patients who had distant metastasis within one year after radical cystectomy also showed a significant increase in RI in contrast to 8 patients who had no metastasis for more than 1 year. Increased RI may be said to be an important risk factor in predicting the development of distant metastasis and recurrent tumor after surgical interventions.