INTERPHASE CYTOGENETIC ANALYSIS OF PROSTATIC CARCINOMAS BY USE OF NONISOTOPIC IN-SITU HYBRIDIZATION

To gain a better understanding of chromosomal aberrations in direct co rrelation with histology, we studied tumor material from 35 patients ( 36 regions) with primary prostate carcinoma by nonisotopic in situ hyb ridization. Nine biotinylated DNA probes were used on serial paraffin sections (centromer-specific probes for X, Y, 1, 7, 8, 10, 17, and 18, and a telomer-specific probe for 1p; ONCOR). Of the 324 hybridized se ctions, 94% were suitable for evaluation. In 34 of the 35 cases (35 of 36 regions) 1-8 chromosomal aberrations were detected. Chromosome X s howed supernumerary centromer copies in 44% of cases. The probes for c hromosomes 1, 1p, 10, and 18 demonstrated deletions in 25, 23, 40 and 58% of eases, respectively. Gains as well as deletions were present fo r Y, 7, 8, and 17 in 31, 25, 36, and 58% of cases, respectively. In 27 % of cases discordant copy numbers of the centromer- and the telomer-s pecific probes for chromosome 1 were observed. No aberration which mig ht be specific for prostate cancer could be established. The rate of a neusomy increased significantly with histological grade. Intratumoral heterogeneity of chromosomal aberrations was revealed in one case. Due to the higher sensitivity of nonisotopic in situ hybridization, aneus omic cases outnumbered cases with cytometrically determined DNA aneupl oidy. In view of published results of metaphase preparations, the high frequency of aneusomy and some of the chromosomal aberrations detecte d by nonisotopic in situ hybridization were unexpected.