A DNA ploidy pattern of prostatic adenocarcinoma was studied by flow cytometry using the formalin-fixed, paraffin-embedded tissues obtained from 65 patients. These patients received hormone therapy preoperatively. Forty cases (61.5%) showed a diploid pattern, and 25 (38.5%) an aneuploid pattern.
Comparing this ploidy pattern with histological classification, the aneuploid pattern was found in 13 cases (52%) of poorly differentiated group, 12 cases (48.0%) of moderately differentiated group and 0 case (0%) of well differentiated group. Thus, rate of aneuploid pattern increased with an increase in the grade of malignancy.
Five years survival rate was 62.6% in the diploid group while it decreased to 30.9% in the aneuploid group. There was a significant difference between the two groups. In 23 cases with stage D, the ploidy pattern of primary region could be compared with that of metastatic region (lymph nodes). The prognosis of patients who exhibited the aneuploid pattern in metastatic region was significantly worse than that of other patients.
These data suggested that flow cytometric DNA analysis of prostatic cancer materials after hormone therapy also produces meaningful information in predicting the prognosis of prostatic cancer.