GENOTYPIC CHARACTERIZATION OF PROSTATIC CARCINOMAS - A COMBINED CYTOGENETIC, FLOW-CYTOMETRY, AND IN-SITU DNA HYBRIDIZATION STUDY

Cytogenetic studies were performed on 36 biopsies obtained from 26 pri mary prostatic adenocarcinomas. Following histopathological characteri zation of control sections, the biopsies were investigated using metap hase cytogenetics, DNA flow cytometry, and fluorescence in situ DNA hy bridization. In 12 specimens, no carcinoma was found in control sectio ns by histopathological means. In 24 carcinoma biopsies clonal aberrat ions were detected in 15 specimens. Tetraploidy as sole aberration was detected in five specimens. Loss of the Y chromosome was seen in eigh t samples. Only one tumor revealed structural abnormalities. Eight sam ples were found to be normal (46,XY). Remarkably, nonclonal chromosome aberrations, particularly marked chromosome loss, were frequently det ected in prostatic carcinomas and premalignant lesions (prostatic intr aepithelial neoplasia). In the series of biopsies investigated by mean s of cytogenetics and flow cytometry, biopsies with aneuploid DNA cont ent were found to be cytogenetically normal. Conversely, the cytogenet ically aberrant clones were found to be of diploid DNA content. Eviden ce of focal intratumoral heterogeneity was revealed by cytogenetics, f low cytometry, and in situ hybridization.