Flow cytometric analysis of DNA-aneuploidy subgroups and proliferation in renal cell carcinoma

Background: the course of patients suffering from renal cell carcinoma vari es considerably and cannot be predicted by tumor stage and grade alone. How ever, it is crucial to select patients with high risk of progression and to commence adjuvant immuno-chemotherapy in good time. Materials and Methods: Multiple samples of 71 kidney tumors were studied by DNA flow cytometry. a neuploidy was classified into subgroups employing the DNA-index. In tumors of euploid pattern and corresponding normal tissue cell cycle analysis was performed. Results: 39% of tumors were found to be aneuploid. Mean prolifer ation fraction was distinctly higher in euploid tumors (15.6%) than in norm al tissue (6.1%). DNA ploidy pattern correlated significantly (p < 0.05) wi th histological grading. With increasing tumor size the clonal spectrum cha nged as well: Tetraploid cell lines fell from 40% to 28%. The number of tri ploid clones rose from 33% to 56%. Conclusion: Based on selection of tri- a nd hypertetraploid carcinomas, a high-risk-group for tumor recurrence can b e associated within the predominating T2/3 G2 kidney tumors. The aim is to treat these patients following curative surgery at the stage of probable mi cro-metastases while keeping risk of overtreatment as low as possible.