CYTOGENETIC AND PLOIDY ANALYSIS OF PROSTATIC ADENOCARCINOMA

The cytogenetic evaluation of prostatic adenocarcinoma has shown no co nsistent cytogenetic abnormalities. Despite manipulation of culture co nditions, the majority of low-stage, untreated prostatic adenocarcinom as show a normal karyotype. We have performed cytogenetic analysis on eight primary prostate adenocarcinomas, using several control measures to increase the probability that any normal karyotype was derived fro m neoplastic cells rather than accompanying normal cells. Tumors were grown in media that encourages epithelial growth; DNA ploidy studies w ere performed before and after tissue culture; and immunohistochemical confirmation of the prostatic and epithelial nature of the cells was done following culture. Percentage of tumor on tissue sections adjacen t to those submitted for culture was >75% in all cases. Seven of eight cases were evaluable, and six cases showed no clonal abnormalities an d were diploid. One tumor showed a population of tetraploid cells, wit hout structural abnormalities. Three additional tumors showed evidence of tetraploidy by DNA analysis. One case showed nonclonal marker chro mosomes and was aneuploid. This patient was pathologic Stage D. We con clude that the majority of prostatic adenocarcinomas at their inceptio n may not show routinely detectable cytogenetic abnormalities. However , tetraploidy may play a role in the evolution of prostatic adenocarci noma.