We trid to find out any differences between initial characteristics of androgen receptors and of relapse after castration in 6 stage D2 prostatic cancer (mean age, 68.7±4.6) (Gleason score 5, 8, 9 ; 1, 3, 2 patients respectively), with
immunohistochemical expression using the mouse monoclonal antibody against human androgen receptor. The prostate specimens were obtained by either transretal needle biopsy or transurethral resection at the time of initial disgnosis and of relapse
following castration. The age matched 6 benign prostatic hyperplasia (BPH) specimens were used as control. 200 cancer cells were chosen and staining intensity of each nuclei was graded (0-absent, +1-weak, +2-meoderate, +3-strong0 from randomly
selected
and photographed from 10 different fields of each specimen.
The means of staining intensity of nuclei from BPH and prostatic canser before treatment were 1.93±0.03 and 1.59±0.03 repsectively (p<0.05). At the time of relapse after bilateral orchiectomy (mean, 24.5±5.0months), the mean staining intensity
of
nuclei of all cancer patients (1.38±0.03) was significantly different from that of before treatment (p<0.05). But in individual comparison, we could find the decrement in only 2 patients. The intervals of relapse from castration of these two
patients
(29 and 32 months) were longer than the mean of 6 patients.
In conclusion, androgen receptors are still expressed significantly after castration in prostatic cancer. In some patients (2/6), castration down regulates the expression of androgen receptors and the down regulation closely correlated with the
relapse
time.
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