Effect of androgen deprivation on epithelial and mesenchymal tissue components in localized prostate cancer

Objective To measure the area distribution of epithelial and mesenchymal components in the prostate of patients with localized prostate cancer after temporary androgen deprivation. Patients and methods Surgical specimens from 38 patients treated with the gonadotrophin-releasing hormone agonist triptorelin for 3 months before radical prostatectomy were examined (group 1). Specimens from a second group of 54 patients who underwent the same surgical procedure with no prior therapy were used as controls (group 2). The specimens were serially step-sectioned and whole-mount tissue sections prepared. The epithelial, smooth muscle and connective tissue components were stained separately with immunohistochemical and histochemical techniques, respectively. Using colour-based image analyses, the tissue components were classified into three categories, displayed in different colours. The percentage of tumour areas occupied by cancer epithelial cells, connective tissue and smooth muscle was determined. Results In specimens from group 1, the cancer epithelium was sparse and scattered throughout the tumour area. A mean (so) of 21 (11)% of the area was occupied by cancer cells, compared with 40 (11)% in the corresponding material from group 2 (P<0.001). The connective tissue/smooth muscle ratio in stroma (about 1 : 1) was similar in both groups. Conclusions Neoadjuvant hormone treatment of patients with localized prostate cancer was associated with a marked reduction in tumour density and thus in the total amount of cancer epithelium.