DNA analysis by flow cytometry of paraffin embedded core biopsies of the prostate

Abstract

The majority of literature concerning DNA analysis of prostate cancer involves testing formalin-fixed prostatectomy tissue, fresh or formalin-fixed transurethral resections of the prostate (TURP), or fresh core biopsies. We were interested if flow cytometry could analyze the DNA of formalin-fixed, paraffin-embedded, core biopsies separated into normal versus malignant segments. Of the 50 potentially available samples for analysis representing 11 controls of normal core tissue and 39 core biopsies from the 11 patients, one patient had no normal tissue, one core had no malignancy, and three cores had no tissue visibly remaining in the paraffin blocks for analysis. Therefore, of 45 actual samples available for processing, sometimes representing segments as small as 0.2 cm, separate segments containing malignant glands or normal glands were excised from the blocks, and processed separately by the Hedley technique. Forty-four of the 45 available samples produced interpretable DNA histograms as defined by discernible G0/G1 peaks, a calculable cell cycle analysis, and the qualitative appearance of a "smooth" histogram appearance, reflecting sufficient nuclei were analyzed. This is the first report to our knowledge where flow cytometry has successfully been used to analyze paraffin blocks of core biopsies which were, in addition, separated into malignant versus normal enriched segments.

Evaluating prostate needle biopsy: therapeutic and prognostic importance

“…DNA ploidy pattern correlates with cancer grade, tumor volume, and stage 113,114 . Most low‐stage tumors are diploid, and high‐stage tumors are nondiploid, but many exceptions occur 115 …”

“…DNA ploidy pattern correlates with cancer grade, tumor volume, and stage. 113,114 Most low-stage tumors are diploid, and high-stage tumors are nondiploid, but many exceptions occur. 115 Patients with diploid tumors have a more favorable outcome than those with aneuploid tumors; for example, among patients with lymph node metastases treated with radical prostatectomy and androgen-deprivation therapy, those with diploid tumors may survive 20 years or more, whereas those with aneuploid tumors die within 5 years.…”

Fattori predittivi nelle biopsie prostatiche

“…DNA ploidy pattern correlates with cancer grade, tumor volume, and stage [37,38]. Controversy exists, however, about whether it is a significant predictor above Gleason score in multivariate analysis.…”