Numerical chromosomal anomalies in latent adenocarcinomas of the prostate

BACKGROUND. Even the high incidence of clinically diagnosed prostate cancer is exceeded by the frequency of tumors detected at autopsy. However, there is some debate concerning the malignant potential of these so-called "late nt prostate cancers." in this study, prostate cancers detected at autopsy w ere investigated for the presence of numerical aberrations of chromosomes 7 , 10, 17, X and Y. METHODS. Prostates from 57 autopsies, performed on male patients aged 45 ye ars or older, were histologically investigated for the presence of cancer. Interphase cytogenetics, an in situ hybridization method with chromosome-sp ecific probes, was performed on paraffin sections. RESULTS. Of the 57 specimens investigated, 23 contained foci of prostate ca ncer. Three prostates contained more than one tumor focus. Interphase cytog enetics could be performed successfully in 19 specimens. Of the 22 tumor fo ci investigated, 14 were disomic and 8 were nondisomic for the five chromos omes tested. Ploidy correlated significantly with the presence of a Gleason score of 7 or higher (P = 0.0109), but not with a tumor volume larger than 0.5 cm(3), or with patient age over 75 years. CONCLUSIONS. Some latent prostate cancers display a nondisomic chromosomal status and a low histologic differentiation in spite of a small tumor volum e, suggesting a more aggressive potential in a subset of these tumors. (C) 1999 Wiley-Liss, Inc.