Preoperative histological and cytological diagnosis and DNA ploidy assessment of localized prostatic cancer

Abstract

The preoperative biopsy specimens of 49 men who underwent radical prostatectomy were compared with serially step‐sectioned operative specimens, in order to evaluate diagnostic accuracy as regards the presence of cancer, its grade and its DNA ploidy. Both the FNAB and TRUS‐GCB undergraded the cancer by one WHO grade in about 35–40% of cases. In cases where both biopsy types were available, the degree of undergrading was the same. Determination of DNA ploidy by the single‐cell technique from FNAB had a sensitivity for detecting non‐diploid DNA patterns of 59% whereas flow cytometric measurement of core biopsies had a sensitivity of 44.4% as regards non‐diploid DNA, when compared with operative specimens. A comparison of ploidy in core biopsies versus ploidy in fine‐needle aspirates revealed that more non‐diploid DNA patterns were diagnosed in the fine‐needle aspirates. These aneuploid patterns were not all confirmed by flow cytometric evaluation of the operative specimens, in which, however, more aneuploid patterns were diagnosed compared with the single‐cell technique from FNAB. We conclude that the standard technique with 1–3 fine‐needle aspirates or 1–3 TRUS‐GCB has a pronounced tendency by both biopsy methods to underestimate the tumour grade. DNA ploidy analysis by FNAB and the single‐cell cytometric method reveals aneupolid cell lines not found in the flow cytometric evaluation. In order to determine whether this reflects a methodological problem or a true discrimination between the ability of the two methods to find non‐diploid cell lines further studies are needed. However, for a more correct preoperative assessment of tumour grade and DNA ploidy, more extensive sampling is required.

DNA Ploidy Patterns in Androgen-Deprived Localized Prostate Cancer

“…The patients were of the same age and were not on treatment with cytotoxic drugs. When admitted they showed no difference in tumor grade [15,28], None of them had evidence of métastasés. Moreover, the same technique in the same laboratory was used for all the DNA analyses.…”