LOSS AND GAIN OF CHROMOSOME-1, CHROMOSOME-18, AND CHROMOSOME-Y IN PROSTATE-CANCER

Nuclear suspensions of 42 prostate carcinoma specimens obtained at sur gery were used to investigate loss and gain of chromosomes 1, 18, and Y by fluorescence in situ hybridization (FISH) with centromere-specifi c probes. The outcome of FISH analysis was correlated with clinical pa rameters and the relationship between DNA-FCM (ploidy at cellular leve l) and FISH (ploidy of individual chromosomes) was assessed. Significa nt loss of chromosomes 1 and 18 was infrequent (respectively, three an d five cases), but 53% of the tested specimens showed loss of Y. Loss was not correlated with DNA ploidy. Significant gain occurred in 36% ( chromosome 1), 63% (chromosome 18), and 28% (Y) of the specimens. Gain of chromosome 18 was shown in DNA diploid (7/14) and aneuploid tumors (18/26), while gain of chromosomes 1 and Y was nearly restricted to D NA aneuploid specimens. Significant unbalance between these chromosome s occurred in 11 cases. Most cases which had significant gain of chrom osome 1 or 18 showed trisomic as well as tetrasomic cells. Simultaneou s loss of some and gain of other investigated chromosomes is suggestiv e of clonal heterogeneity and/or multiclonality. This was observed in eight tumors. Correlation between DNA-FCM and FISH was best for the Y chromosome. DNA-FCM showed more aberrant histograms with increasing st age and grade of tumors. The presence of numerical aberrations of the investigated chromosomes however, seemed independent of clinical grade or stage. (C) 1994 Wiley-Liss, Inc.