Bromodeoxyuridine and deoxyribonucleic acid bivariate analysis in human renal cell carcinoma. Does flow cytometric determination predict malignant potential or prognosis of patients with renal cell carcinoma?

Sixty-one renal cell carcinomas were analyzed by simultaneous flow cytometric bivariate measurements of deoxyribonucleic acid (DNA) and bromodeoxyuridine. Bromodeoxyuridine in vitro labeling was performed by sample incubation with bromodeoxyuridine under hyperbaric oxygen. DNA ploidy status statistically correlated only with the presence or absence of distant metastasis. When the mean bromodeoxyuridine labeling index (LI) was accordingly compared with each histologic feature, architecturally solid, grade 3, high-stage (beyond pT3a) tumor, and the presence of distant metastasis showed significantly higher LI. When LI were compared with DNA ploidy, diploid tumors showed a 6.3% +/- 4.9% LI, whereas aneuploid tumors exhibited a 7.6% +/- 5.4% LI. The difference was not statistically significant. Five patients with a mean survival time of 10.2 +/- 4.1 months who had a mean LI of 11.5% +/- 7.7% died, whereas 56 patients with a mean LI of 6.7% +/- 4.8% survived. The difference was significant (P less than 0.05). However, the results did not necessarily correlate with the histologic features of the malignant potential or with the prognosis in individual patients. These data indicate that flow cytometric DNA/bromodeoxyuridine bivariate analysis remains inconsistent for predicting the malignant potential or prognosis of renal cell carcinoma.