DNA heterogeneity in prostatic adenocarcinoma. A DNA flow cytometric mapping study with whole organ sections of prostate.
BACKGROUND
The degree of DNA heterogeneity varies between tumors arising at different sites. The presence of a significant degree of variability within a given tumor may result in problems in the interpretation of DNA flow cytometric findings. This study evaluated the degree of DNA heterogeneity in prostatic adenocarcinoma.


METHODS
A total of 122 3-mm punch biopsy specimens were evaluated from single representative whole organ sections from nine cases of prostate cancer (range, 4-18 samples per case; mean, 12 samples; median, 14 samples). Individual punch biopsy specimens were graded and reviewed to confirm the presence of carcinoma and processed for DNA ploidy analysis.


RESULTS
Assessable histograms, defined as having a coefficient of variation of the diploid G0/G1 peak of 7.5% or less, were available for 111 (91%) of the samples. Of the nine cases studied, five (56%) showed heterogeneity in the DNA pattern (diploid plus aneuploid, n = 1; diploid plus tetraploid, n = 2; and diploid plus tetraploid plus aneuploid, n = 2). All four cases having a homogeneous DNA content were DNA diploid in all samples. In those cases with a heterogeneous pattern, the areas having abnormal DNA patterns could not be predicted by histologic pattern or grade.


CONCLUSIONS
From this study, the authors conclude that a significant degree of DNA heterogeneity exists within individual cases of prostatic adenocarcinoma, and this may be an important confounding factor in DNA ploidy studies.
O'Malley
F P
FP
Department of Pathology, Victoria Hospital, University of Western Ontario, London, Canada.
Grignon
D J
DJ
Keeney
M
M
Kerkvliet
N
N
McLean
C
C
D000230:Adenocarcinoma / Q000235:genetics* / Q000473:pathology; D000782:Aneuploidy; D001706:Biopsy; D004273:DNA, Neoplasm / Q000032:analysis*; D004171:Diploidy; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D008297:Male; D011003:Ploidies; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000473:pathology; D016192:Resting Phase, Cell Cycle
D004273:DNA, Neoplasm