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Radioimmunoscintigraphy using a radio-labelled antibody to prostate-specific membrane antigen (PSMA) has growing applications as a means of tissue-specific imaging based on functional characteristics and complements traditional staging investigations. Clinical applications in men with carcinoma of the prostate are being refined, and this study reports outcomes with this technique in our practice. Prostatic immunoscintigraphy scans were performed with In-111 CYT 356 in 49 men with carcinoma of the prostate, obtaining sequential images in two and three dimensions at 10 min, 24 and 48 h. Of the 49 men, 36 had clinically localized cancer, 10 had recurrent disease after radical radiotherapy or radical prostatectomy and three had rising PSA after primary endocrine treatment. Scan findings are discussed in the context of clinical management. Of the 36 men with clinically localized cancer, seven had increased uptake in regional and distant lymph nodes. Of these seven, three were treated with hormone manipulation, two by radical prostatectomy and two by radical radiotherapy. Among 10 patients who had recurrence after radical treatment of the primary tumour, scans showed local recurrence alone in four, and six had regional or distant metastases. Three patients treated with primary hormone manipulation had scans for rising PSA, and of these one had a positive regional node and two had distant soft tissue and bone metastases. In conclusion, prostatic radio-immunoscintigraphy scans highlight tissues involved by prostate cancer, including the prostate, lymph nodes, soft tissues and bone metastases as well as pelvic recurrence. Results may contribute to the clinical management of individual patients, although histological confirmation may be appropriate when considering alternative treatment. Prostate Cancer and Prostatic Diseases (2000) 3, 47-52

Finasteride is widely used for the treatment of benign prostatic hyperplasia (BPH). Its therapeutic efficacy is believed to be mediated through selective inhibition of prostatic 5alpha-reductase (type II). This prospective, controlled, randomized study examines various relationships between changes in tissue 5alpha-reductase isozyme activity, epithelial proliferative index and morphology in men with BPH treated with finasteride for 6 months, and correlates these with clinical response. Thirty-one patients presenting with symptomatic bladder outflow obstruction were prospectively randomized to receive either finasteride or placebo (2:1) for 24 weeks. Of these, 27 men aged 55-80 y (median 69 y) completed the study, including 18 patients on treatment. Symptom score determination, uroflow and prostate volume were assessed at baseline and end of study. Prostatic tissue was obtained by ultrasound-guided needle biopsy at baseline and by transurethral resection (TURP) at end of study for biochemical and morphometric analysis. Epithelial proliferation was examined quantitatively in the resected tissue using MIB-1 antibody to Ki-67 and counting the percentage of positively staining cells. Type II 5alpha-reductase activity was strongly inhibited by finasteride in resected BPH tissue, with over 100-fold decrease in V(max) (P=0.001), whereas the type I isozyme was inhibited 5-fold (P=0.005). Selective inhibition of type II 5alpha-reductase was demonstrated in all treated patients. No significant difference in epithelial proliferation was observed between the finasteride and placebo groups. Epithelial proliferation was, however, greater in prostatic tissue with histological manifestation of inflammation (2.02% vs 0.89%, P=0.001). Positive correlation between the total epithelial volume and the ratio of transition zone volume/total prostate volume was observed in the placebo group (r=0.834), whereas there was no such correlation in men taking finasteride (r=-0.300), consistent with a reduction in epithelial content in the treatment group. Improvement in uroflow and reduction in prostatic volume in patients treated with finasteride did not reach statistical significance. This study shows that finasteride causes inhibition of 5alpha-reductase activity in human BPH tissue with selectivity for the type II isozyme. In spite of this, no significant effects in epithelial proliferation or tissue morphology were demonstrated. The presence of inflammation was, however, associated with significantly greater proliferative activity. The power of this study was limited by the small number of recruited patients, and a larger study would be required for further investigation of morphological changes induced by finasteride in BPH tissue and their biochemical basis.

As high grade PIN is commonly associated with concomitant cancer, current literature recommends re-biopsy of patients with high grade PIN. This paper describes the prevalence of high grade prostatic intra-epithelial neoplasia (PIN) from three independent clinical settings, reported by a single pathologist (MCP). High grade PIN was diagnosed in biopsies from 131 of the 1205 (11%) of patients in whom cancer was suspected in hospital practice, 42 of the 202 (20%) asymptomatic men screened for prostate cancer and 29 of the 118 (25%) patients presenting with prostatism in a case finding study. Re-biopsy on this scale has major clinical and cost implications. However, from a literature review, there is evidence to suggest that the risk of concomitant cancer with high grade PIN may be stratified according to serum PSA. This opinion should be tested prospectively.