Flow cytometry analysis of urothelial cell DNA content according to pathological and clinical data on 100 bladder tumors.

DNA content of 100 bladder tumors (34 grade I, 42 grade II and 24 grade III, WHO classification) were studied by flow cytometry. Ten normal bladder samples were used as control. The 100 bladder tumors could then be separated into two groups. A first group of 60 tumors (60%) had a unimodal distribution with a diploid peak and a DNA index close to 1.0, 32 grade I, 22 grade II and 6 grade III tumors displayed this pattern as did the 10 normal bladders. The second group (40%) had a bimodal distribution with two peaks, the first one (diploid peak) with a DNA index of 1.0, the second (aneuploid peak) with a DNA index greater than 1.0. Two grade I, 20 grade II and 18 grade III tumors belonged to this group. Frequency of the aneuploid peak increased with tumor grade and infiltration progression. Hence 6% of grade I, 48% of grade II and 75% of grade III tumors showed an aneuploid peak as well as 8% of Pa, 46% of P1, 73% of P2 and 87.5% of P3 stage tumors. This study showed that a good correlation exists between flow-cytometric, pathological and clinical data.