DNA ploidy patterns in androgen-deprived localized prostate cancer.

Prostatectomy was performed in 48 patients with localized prostate cancer. Before surgery, they had been treated with the GnRH agonist triptorelin for 3 months. Specimens from the largest tumor focus (n = 6.3 + 3.6, mean + SD) were analyzed with regard to the DNA ploidy pattern. The results were compared with those obtained in a previous investigation of 54 patients who were subjected to surgery without hormone pretreatment. In both series, about 50% of the tumors showed a diploid DNA ploidy pattern, the rest being nondiploid. Ploidy heterogeneity, i.e., a mixture of diploid and nondiploid ploidy patterns in the single largest tumor focus, was found in 36% of the cases compared to 48% in the previous report (NS). In 13% of the tumors, all samples revealed a nondiploid DNA ploidy pattern as compared to 6% in the previous report (NS). In both series, needle biopsy examination (1/patient) prior to prostatectomy was associated with a significant and similar underestimate of the chromosomal aberration. In conclusion, despite the marked histopathological changes previously reported, there is no evidence that neoadjuvant triptorelin treatment during 3 months has any effect on the DNA ploidy pattern.