Background: The incidence of upper urinary tract tumors is relatively high in southern Taiwan. DNA analysis by means of flow cytometry is not well investigated with regard to tumors of the upper urinary tract and the differences in DNA ploidy between transitional cell carcinomas in endemic and nonendemic areas.
Methods: A retrospective nuclear DNA ploidy analysis by flow cytometry comprised 41 formaldehyde solution-fixed, paraffin-embedded tissue specimens of transitional cell carcinoma of the renal pelvis and ureter. The preparation of nuclear suspensions from paraffin-embedded tissue blocks and staining were modified by means of the techniques of Hedley and Vindeløv.
Results: There was no statistical correlation between DNA ploidy, histologic grade, and pathologic stage, however, 82% of the DNA nondiploid tumors showed tumor progression. In contrast, only 46% of the DNA diploid tumors revealed tumor progression. Among Grade 2 tumors, 85% of the DNA nondiploid tumors showed postoperative tumor progression, whereas only 31% of the DNA diploid tumors showed tumor progression. Seventy-nine percent of the nondiploid patterns were present in patients native to the Pa Chang Valley, where the so-called "blackfoot disease" and urothelium tumor are endemic, whereas only 22% appeared in patients living in other areas.
Conclusions: DNA flow cytometry can identify a group of patients with poor outcome unpredictable by pathologic examination, and is an important tool in research into the pathogenesis of cancer.