Immunohistochemical Androgen Receptor Change of Relapsed Prostate Cancer After Castration

Choi, Hak Ryong; Han, Sang Won; Shim, Bong Suk; Park, Young Yo; Kwon, Sung Won

Abstract

We tried 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 transrectal needle biopsy or transurethral resection at the time of initial diagnosis 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 (O-absent, +1-weak, +2-moderate, +3-strong) from randomly selected and photographed from 10 different fields of each specimen. The means of staining intensity of nuclei from BPH and prostatic cancer before treatment were 1.93+/-0.03 and 1.59+/-0.03 respectively (p<0.05). At the time of relapse after bilateral orchiectomy (mean, 24.5+/-5.0 months), 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."