Changes in histologic grade and argyrophilic nucleolar organizer regions during progression of prostate cancer.

To determine the changes in histologic features during the course of prostate cancer under long-term endocrine therapy, histologic grade and argyrophilic nucleolar organizer regions (AgNORs) were examined in specimens before treatment, at relapse, and at cancer death. A total of 29 patients who had received therapy and died of prostate cancer were evaluated. Among the 29 cases, biopsy tissues before treatment (25 cases) and during progression from endocrine therapy (10 cases) were compared with autopsy specimens. Histologic grade was determined by the method of Gleason, and the number of AgNORs in cancer cells was counted. Survival of the patients was compared with the histologic features. There was a tendency for a higher grade of cancer during the clinical course. Moreover, a statistically significant increase in the number of AgNORs was observed from pretreatment biopsy to autopsy. Upon comparison of metastatic sites with local cancer at autopsy, no significant difference was noticed in terms of histologic grade or AgNOR count. Although there was no correlation between the number of AgNORs and survival after initial treatment, an inverse relationship was demonstrated between the number of AgNORs and survival in patients with systemic progression after endocrine therapy. In conclusion, prostate cancer shows an increase of malignant potential, as assessed by histologic grade and the number of AgNORs. Patients with cancer of high proliferative ability showing high grade and greater numbers of AgNORs have poorer prognosis from progression.