Flow cytometric DNA analysis on renal cell carcinoma--a study of 116 cases on fresh surgical specimens

Abstract

DNA ploidy was investigated using flow cytometry on fresh surgical specimens from 116 cases with renal cell carcinoma. DNA diploid tumor was observed in 39 cases (33.6%) and aneuploid in 77 cases (66.4%). DNA aneuploid group was further classified into 3 subgroups by DNA index (D.I.); near-diploid group (D.I.: 0.8-1.2, 21.6%), near-tetraploid group (D.I.: 1.8-2.2, 12.9%) and other aneuploid group (31.9%). DNA ploidy pattern correlated with clinical stages and histological grading, indicating significantly a higher incidence of DNA diploid in cases in stage I and grade 1. DNA clonal heterogeneity was observed in 48.1%, and homogeneously diploid was in 28.6% of 77 cases who were analyzed more than 2 specimens. Incidences of DNA heterogeneity and homogeneous diploid correlated with the number of analyzed specimens and our results showed that more than 4 specimens were necessary to diagnose the DNA ploidy patterns. The near-tetraploid group was shown to have an extremely poor prognosis compared with the diploid group and the other aneuploid group. There were no significant difference between the diploid group and the aneuploid group in terms of the early prognosis, however, the incidence of disease recurrence was significantly higher in the aneuploid group. Our results demonstrated that DNA ploidy was an useful prognostic factor in the evaluation of patients with renal cell carcinoma.