RESUMEN
1. While there are extensive data showing that aneuploidy is associated with adverse outcome in stage D prostate cancer, the utility of ploidy analysis in stage B disease in unclear. We determined ploidy in radical prostatectomy specimens from 28 patients with clinical stage B prostate cancer, and with a mean follow-up of 4.1 years (2-10 years). Patients who had no recurrences had a minimum 5 years of follow-up. Patients who had only 2 years of follow-up were included if they had developed bone metastases during this period. 2. Ploidy determinations were done on Feugen-stained 5-µm paraffin-embedded sections using a CAS 200 image analyzer. At least 400 tumor cells were counted in every case. Tumors with at least 70 percent diploid cells were classified as diploid, while those with less than 70 percent diploid cells were classified as aneuploid. The mean percentage of diploid cells in tumors classified as diploid was 90.6 ñ 7.4, while the mean percentage of diploid cells in tumors classified as aneuploid was 36 ñ 21.9. 3. Ploidy status correlated with disease progression: seven of the 10 patients (70 percent) with disease recurrence had aneuploid tumors, while 13 of 18 patients (72 percent) who remained disease-free had diploid tumors (P= 0.03, Chi-square test). 4. These data show that patients with stage B disease with aneuploid tumors at the time of prostatectomy are more likely to have recurrent disease within a mean of 3 years (2-6 years) compared to patients with diploid tumors. Ploidy determination done at the time of surgery may offer useful prognostic information