Immunohistochemical expression and localization of somatostatin receptor subtypes in androgen ablated prostate cancer.

OBJECTIVE: The aim was to examine the expression and localization of the five somatostatin receptors (termed SSTR1 to 5) in radical prostatectomies (RPs) from patients with prostatic adenocarcinoma (PCa) under complete androgen ablation (CAA) before operation. MATERIAL: The five SSTRs were evaluated in the epithelial, smooth muscle and endothelial cells of normal-looking epithelium (Nep), high-grade prostatic intraepithelial neoplasia (HGPIN) and PCa in 20 RPs with clinically detected PCa from patients under CAA. Twenty RPs with clinically detected PCa from hormonally untreated patients were used as control group. RESULTS: Concerning the secretory cells (i) Membrane staining was seen for SSTR3 and SSTR4; the mean percentages of positive cells, higher in SSTR3 than in SSTR4, decreased sharply in HGPIN and PCa compared with Nep; the mean percentages in the androgen ablated group were 30% to 90% lower than in the untreated; (ii) Cytoplasmic staining was seen for all five SSTRs; the mean percentages of positive cells in Nep, HGPIN and PCa of the untreated group were similar, and in general as high as 80% or more; in the treated group, the Nep values were similar to those in the untreated, whereas the values in HGPIN and PCa were lower for SSTR1, three and five, with a decrease of 30% for SSTR1; (iii) Nuclear staining was seen with SSTR4 and SSTR5, the mean percentages for the former being much lower than for the latter; treatment affected both HGPIN and PCa, whose proportions of stained cells were 30% to 55% lower than in the untreated group. Cytoplasmic staining in the basal cells was seen for all five SSTRs, both in Nep and HGPIN. The values in the treated group were lower than in the other, the difference between the two group being in general comprised between 10% and 40%. Treatment did not affect SSTR staining in the smooth muscle and endothelial cells. CONCLUSIONS: The present study expands our knowledge on the expression and localization of the five SSTRs in the prostate following CAA.

Somatostatin receptor subtypes in hormone-refractory (castration-resistant) prostatic carcinoma.

The aim of this study was to examine the tissue expression and localisation of the somatostatin receptors (SSTRs) in hormone-refractory (HR) prostate cancer (PCa). Five SSTRs were evaluated immunohistochemically in 20 radical prostatectomies (RPs) with Gleason score (GS) 3+3=6 PCa, in 20 RPs with GS 4+4=8 and 4+5=9 PCa, and 20 transurethral resection of the prostate specimens with HR PCa. The mean values in the cytoplasm (all five SSTRs were expressed), membrane (only SSTR3 and SSTR4 were expressed) and nuclei (only SSTR4 and SSTR5 were expressed) of the glands in HR PCa were 20-70% lower than in the other two groups, the differences being statistically significant. All five SSTRs were expressed in the smooth muscle and endothelial cells of HR PCa, the mean values being lower than in the other two groups. In conclusion, this study expands our knowledge on the expression and localisation of five SSTRs in the various tissue components in the HR PCa compared with hormone-sensitive PCa.

Immunohistochemical expression and localization of somatostatin receptor subtypes in androgen ablated prostate cancer.

OBJECTIVE: The aim was to examine the expression and localization of the five somatostatin receptors (termed SSTR1-5) in radical prostatectomies (RPs) from patients with prostatic adenocarcinoma (PCa) under complete androgen ablation (CAA) before operation. MATERIAL: The five SSTRs were evaluated in the epithelial, smooth muscle and endothelial cells of normal-looking epithelium (Nep), high-grade prostatic intraepithelial neoplasia (HGPIN) and PCa in 20 RPs with clinically detected PCa from patients under CAA. 20 RPs with clinically detected PCa from hormonally untreated patients were used as control group. RESULTS: Concerning the secretory cells (i) membrane staining was seen for SSTR3 and SSTR4; the mean percentages of positive cells, higher in SSTR3 than in SSTR4, decreased sharply in HGPIN and PCa compared with Nep; the mean percentages in the androgen ablated group were 30-90% lower than in the untreated; (ii) cytoplasmic staining was seen for all 5 SSTRs; the mean percentages of positive cells in Nep, HGPIN and PCa of the untreated group were similar, and in general as high as 80% or more; in the treated group, the Nep values were similar to those in the untreated, whereas the values in HGPIN and PCa were lower for SSTR1, 3 and 5, with a decrease of 30% for SSTR1; (iii) nuclear staining was seen with SSTR4 and SSTR5, the mean percentages for the former being much lower than for the latter; treatment affected both HGPIN and PCa, whose proportions of stained cells were 30-55% lower than in the untreated group. Cytoplasmic staining in the basal cells was seen for all 5 SSTRs, both in Nep and HGPIN. The values in the treated group were lower than in the other, the difference between the two group being in general comprised between 10 and 40%. Treatment did not affect SSTR staining in the smooth muscle and endothelial cells. CONCLUSIONS: The present study expands our knowledge on the expression and localization of the five SSTRs in the prostate following CAA.

Sorafenib's inhibition of prostate cancer growth in transgenic adenocarcinoma mouse prostate mice and its differential effects on endothelial and pericyte growth during tumor angiogenesis.

OBJECTIVE: To evaluate Sorafenib's efficacy (60 mg/kg/d per os) in preventing the transformation of high grade prostate intraepithelial neoplasia (HGPIN) into adenocarcinoma (ADC) and in inhibiting the onset and progression of poorly differentiated carcinoma (PDC) in transgenic adenocarcinoma mouse prostate (TRAMP) mice. STUDY DESIGN: Forty-four TRAMP mice were randomly divided into 2 groups of 22 and assigned to daily treatment by gavage with vehicle only or Sorafenib from the 10th to the 26th week of age. At 26 weeks of age the mice were killed, and their genitourinary apparatus was removed and examined by histology, immunohistochemistry and confocal microscopy. RESULTS: Sorafenib reduced HGPIN growth and progression to ADC and was probably also effective in PDC inhibition. The major effect of Sorafenib was on tumor angiogenesis. Interestingly a dissociation between endothelial cells and pericytes was noted in treated PDC since inhibition of pericyte recruitment was less complete than that of endothelial cells. CONCLUSION: Sorafenib's potent antiangiogenic action may be supposed to be exerted primarily by inhibiting endothelial proliferation and sprouting, whereas its inhibition of pericyte recruitment and maturation is less complete. These observations suggest that Sorafenib's effects could be improved by the joint employment of substances capable of interfering with the recruitment and organization of pericytes.

Immunohistochemical expression of somatostatin receptor subtypes in prostate tissue from cystoprostatectomies with incidental prostate cancer.

OBJECTIVE: To examine immunohistochemically the expression of the five somatostatin receptors (SSTRs) in cystoprostatectomies (CyPs) with incidental prostate cancer. MATERIALS AND METHODS: The five SSTRs (SSTR1-5) were evaluated in 'normal-looking' epithelium (NEp), high-grade prostatic intraepithelial neoplasia (HGPIN) and pT2a Gleason score 6 adenocarcinoma in 20 CyP specimens with incidental prostate cancer and 20 radical prostatectomy (RP) specimens with clinically detected prostate cancer. RESULTS: For cytoplasm expression, the mean percentage of positive secretory cells with strong cytoplasmic staining increased from NEp to HGPIN and prostate cancer, being slightly lower in the CyP than in the RP specimens. Both in the CyP and RP specimens SSTR4 was found in the highest percentage of cells. There was membrane staining in the secretory cells for SSTR3 and SSTR4. There was nuclear staining in the secretory cells for SSTR4 and SSTR5. For SSTR1 and SSTR3 the mean proportions of positive basal cells were higher than for the other three subtypes, and greater in NEp than in HGPIN. There were positive smooth muscle and endothelial cells for all five SSTR subtypes, the highest proportions being SSTR1 and the lowest SSTR5. CONCLUSIONS: This immunohistochemical study expands our knowledge of the expression and localization of SSTRs in the various tissue components in the prostate with incidental cancer, compared with clinically detected cancer. Such information might be useful in developing further non-invasive strategies for the prevention and treatment of pre-neoplastic and neoplastic lesions of the prostate.

GnRH receptor expression in human prostate cancer cells is affected by hormones and growth factors.

GnRH receptors (GnRH-R) have been found in various malignancies, including prostate cancer (PCa). They mediate the direct antitumor effects of GnRH analogs. Nevertheless, few reports concern drug-induced modulation of GnRH-R levels. In this study, we investigated GnRH-R expression in androgen-sensitive (LNCaP) and -insensitive (PC-3) PCa cells treated for 4 and 6 days with a GnRH agonist (Leuprorelin acetate, LA, 10(-11) or 10(-6) M), Dihydrotestosterone (DHT, 10(-9) M), Cyproterone acetate (CA, 10(-7) M), and Epidermal growth factor (EGF, 10 ng/ml), either alone or combined. The RT-PCR analysis showed no variation in GnRH-R mRNA levels of both treated LNCaP and PC-3 cells. On the contrary, immunoblotting indicated that in LNCaP and PC-3 cells, LA upregulated membrane GnRH-R expression (up to 92%). In androgen-sensitive cells, DHT induced a GnRH-R increase (up to 119%) always comparable to that occurring in the presence of CA. GnRH-R upregulation by LA/DHT or CA/DHT association was similar to that promoted by the single agents. In PC-3 cells, EGF upregulated GnRH-R (up to 110%). A prolonged treatment (for 12 days) determined a greater EGF-induced increase in GnRH-R levels (142%). Lower (or no) receptor enhancement occurred when LA and EGF were associated. Our findings indicate that LA post-transcriptionally upregulates its own membrane receptor in androgen-sensitive and -insensitive PCa cells, counteracting the receptor enhancement produced by DHT and EGF. The effects, obtained with a relatively long and continuous treatment, may have implications in the choice of therapy modality with GnRH analogs and may render the receptor a novel therapeutic target, particularly in hormone-refractory PCa.

Intermittent androgen deprivation for locally advanced and metastatic prostate cancer: results from a randomised phase 3 study of the South European Uroncological Group.

BACKGROUND: Few randomised studies have compared intermittent hormonal therapy (IHT) with continuous therapy for the treatment of advanced prostate cancer (PCa). OBJECTIVE: To determine whether intermittent therapy is associated with a shorter time to progression. DESIGN, SETTING, AND PARTICIPANTS: 766 patients with locally advanced or metastatic PCa received a 3-mo induction treatment. The 626 patients whose prostate-specific antigen (PSA) level decreased to <4 ng/ml or to 80% below the initial value were randomised. INTERVENTION: Patients received cyproterone acetate (CPA) 200mg for 2 wk and then monthly depot injections of a luteinising hormone-releasing hormone (LHRH) analogue plus 200mg of CPA daily during induction. Patients randomised to the intermittent arm ceased treatment, while those randomised to the continuous arm received 200mg of CPA daily plus an LHRH analogue. MEASUREMENTS: Primary outcome measurement was time to subjective or objective progression. Secondary outcomes were survival and quality of life (QoL). Time off therapy in the intermittent arm was also recorded. RESULTS AND LIMITATIONS: 127 patients from the intermittent arm and 107 patients from the continuous arm progressed, with a hazard ratio (HR) of 0.81 (95% confidence interval [CI]: 0.63-1.05, p=0.11). There was no difference in survival, with an HR of 0.99 (95% CI: 0.80-1.23) and 170 deaths in the intermittent arm and 169 deaths in the continuous arm. The greater number of cancer deaths in the intermittent treatment arm (106 vs 84) was balanced by a greater number of cardiovascular deaths in the continuous arm (52 vs 41). Side-effects were more pronounced in the continuous arm. Men treated with intermittent therapy reported better sexual function. Median time off therapy for the intermittent patients was 52 wk (95% CI: 39.4-65.7). CONCLUSIONS: IHT should be considered for use in routine practice because it is associated with no reduction in survival, no clinically meaningful impairment in QoL, better sexual activity, and considerable economic benefit to the individual and the community.

Immunohistochemical detection and localization of somatostatin receptor subtypes in prostate tissue from patients with bladder outlet obstruction.

BACKGROUND AND AIM OF THE STUDY: Scant information on the cellular distribution of the five somatostatin receptor (SSTR) subtypes in the normal prostate and in neoplasms of the prostate has been reported in very few studies in which techniques, such as in situ hybridization histochemistry, autoradiography, and more recently immunohistochemistry, have been applied. The aim of the study was to examine immunohistochemically the distribution and localization of these 5 subtypes in the various tissue components in normal prostate. MATERIALS: The study was conducted in 14 surgical specimens of normal prostate tissue from adenomectomy specimens from patients with bladder outlet obstruction. The distribution and localization of the 5 somatostatin receptor (SSTR) subtypes was investigated with an immunohistochemical technique. Specificity of the antibodies against the 5 receptor subtypes was preliminarily investigated. RESULTS: Close to 90% of secretory cells showed a weak positivity in the cytoplasm, the proportion ranging from 86.3% (SSTR4) to 89.9% (SSTR5). Strong immunoreactivity was seen in a small proportion of cells, ranging from 0.8% (SSTR3) to 3.2% (SSTR1). For the subtypes 1 and 3 the greatest proportion of basal cells showed a moderate intensity (42.5 and 41.4%, respectively), strong immunoreactivity being observed only in 18.1 and 15.8% of cells, respectively. For the subtypes 2, 4 and 5, the majority of cells showed a weak intensity (72.3, 65.7 and 65.1%, respectively). Subtype 1 showed a strong immunoreactivity in the cytoplasm in 60% of the smooth muscle cells. With subtypes 2, 3 and 4 the greatest proportion of cells showed a weak intensity (63.4, 89.8 and 81.7%, respectively). With the subtype 5 the majority of cells (59.8%) were negative. Subtype 1 showed a strong immunoreactivity in the cytoplasm in 98.6% of the endothelial cells. With subtypes 3 and 4 the greatest proportion of cells showed a weak intensity (73.5 and 56.4%, respectively). With the subtype 2 and 5 the majority of cells were negative (59.1 and 50.7%, respectively).

Bicalutamide 50 mg monotherapy in patients with isolated high-grade PIN: findings in repeat biopsies at 6 months.

OBJECTIVES: To evaluate morphological findings in repeat biopsies in patients with isolated high-grade prostatic intraepithelial neoplasia (HGPIN) after a 6-month course of bicalutamide (Casodex) 50 mg/day. METHODS: 20 consecutive patients with isolated HGPIN in prostate biopsies were treated for 6 months with bicalutamide 50 mg/day. After treatment, the patients were resubmitted to prostate biopsy mapping. The control group included 22 untreated consecutive patients with isolated high-grade PIN with repeat biopsies taken 6 months after the initial biopsies. RESULTS: In the initial biopsies of the treated group, HGPIN was monofocal in 12 patients and plurifocal in 8. In the repeat biopsies HGPIN was present in 2 patients, monofocal in both, whereas prostate adenocarcinoma (PCa) was discovered in one. In the control group, HGPIN was monofocal in 15 and plurifocal in 7. In the repeat biopsies HGPIN was present in six patients, being monofocal in three and plurifocal in the other three. PCa was present in one. CONCLUSIONS: There was a lower incidence of HGPIN (treated group vs control: 10% vs 27.2%) after 6 months of bicalutamide. Reduction in its extent was also observed (treated group vs control: monofocal 100% vs 50%). Treatment did not affect the incidence of cancer (treated vs control: 5% vs 4.5%).

Gene expression profiling of renal cell carcinoma: a DNA macroarray analysis.

OBJECTIVE: To examine differences in gene expression levels between renal cell carcinoma (RCC) tissue and 'normal' appearing renal tissue using a commercially available DNA macroarray. MATERIALS AND METHODS: Tissue was obtained from 47 consecutive radical nephrectomies, 29 of which were eligible. DNA macroarrays were analysed on the tumour and normal-appearing control tissue to measure the expression of 1185 cancer-related genes. The group of samples was also stratified according to the presence or absence of granular cells and according to tumour grade. Quantitative real-time polymerase-chain reaction (PCR) was also performed on seven key genes present on the macroarray. RESULTS: In all, 444 genes were over-expressed and 33 genes were under-expressed. Using selection criteria reduced the list to nine that were significantly over-expressed and 23 that were under-expressed. These significant genes belonged to the families of oncogenes, growth factors, interleukins, receptors, immune system components, cytoskeleton, matrix proteins and intracellular modulators, or they coded for proteins involved in DNA transcription and RNA translation, DNA repair, protein turnover, and metabolism of carbohydrates and lipids. There were differences in gene expression according to the presence or absence of granular cells and according to tumour grade. Using quantitative real-time PCR there was over-expression of epidermal growth factor receptor, c-myc, transforming growth factor-alpha, vascular endothelial growth factor and vimentin, and under-expression of TYRO3 protein tyrosine kinase. The von Hippel-Lindau gene was under-expressed but not significantly. CONCLUSIONS: A procedure for collecting and storing fresh renal tissue and subsequent gene expression profiling of RCC and normal renal tissue was established. A commercially available DNA macroarray coupled with the significance analysis of macroarrays allowed the identification of sets of differentially expressed cancer-related genes that were characteristic of RCC, compared with apparently normal renal tissue, and which distinguished among subgroups divided according to tumour grade and histological subtype. Quantitative PCR is important to validate the results of macroarray experiments.

Histopathology reporting of prostate needle biopsies. 2005 update.

This report reviews the diagnostic and prognostic importance of the pathologic findings in prostate needle biopsies. The morphological findings of the needle biopsy may be placed into one of the following five categories: prostate cancer, atypical small acinar proliferation, high-grade prostatic intraepithelial neoplasia, inflammation, and benign prostatic tissue. While the prime goal of the biopsy is to diagnose prostatic adenocarcinoma, once carcinoma is detected, further descriptive information regarding the type, amount of cancer, and grade forms the cornerstone for contemporary management of the patient and for assessment of the potential for local cure and the risk for distant metastasis. The information provided in the needle biopsy report regarding the attributes of carcinoma is used depending on the individual patient's medical condition and preference and on the treating physician's evaluation to determine whether any form of treatment is indicated and, if so, the type of therapy.

The role of luteinizing hormone-releasing hormone therapy in locally advanced prostate cancer and biochemical failure: considerations for optimal use.

BACKGROUND: More patients are being diagnosed with prostate cancer at an earlier age with earlier stage disease because of advances in screening and detection. Investigators continue to explore the use of hormone therapy, particularly luteinizing hormone-releasing hormone (LHRH) analogues, earlier in the course of disease. OBJECTIVE: This review summarizes clinical evidence regarding the safety and efficacy of LHRH analogues in the treatment of locoregional disease or following biochemical failure. METHODS: Relevant information from clinical studies was identified through a MEDLINE search of the medical literature published in English in the last 5 years (search terms: LHRH and prostate cancer). The search included prospective and retrospective clinical studies on LHRH therapy in locally advanced prostate cancer. Additional relevant publications published before 1999 were identified from citations in the resulting articles. RESULTS: The available clinical evidence suggests that the use of LHRH analogues as adjuvant or neoadjuvant therapy in conjunction with radiation therapy may improve survival outcomes. Few studies have evaluated the use of LHRH analogues after biochemical failure. However, several related studies indicate that initiating hormone therapy earlier rather than later may provide some clinical benefit. When considering early initiation of LHRH therapy, the potential risks of long-term treatment must be considered. Physiologic changes, such as deterioration of body composition and bone quality, may have important effects on the risk of developing cardiovascular disease and osteoporosis. CONCLUSIONS: Although some clinical evidence supports the use of LHRH analogues as adjuvant or neoadjuvant therapy or following biochemical failure, further study is needed. In the meantime, clinicians should carefully weigh the potential benefits and risks of early hormone therapy when making treatment decisions.

Bladder tumor markers beyond cytology: International Consensus Panel on bladder tumor markers.

This is the first of 2 articles that summarize the findings of the International Consensus Panel on cytology and bladder tumor markers. The objectives of our panel were to reach a consensus on the areas where markers are needed, to define the attributes of an ideal tumor marker, and to identify which marker(s) would be suitable for diagnosis and/or surveillance of bladder cancer. Our panel consisted of urologists and researchers from Europe, Asia, and the United States who reviewed original articles, reviews, and book chapters on individual bladder tumor markers published in the English language mainly using the PubMed search engine. Panel members also met during 3 international meetings to write recommendations regarding bladder tumor markers. The panel found that the most practical use of noninvasive tests is to monitor bladder cancer recurrence, thereby reducing the number of surveillance cystoscopies performed each year. Markers also may be useful in the screening of high-risk individuals for early detection of bladder cancer. However, more prospective studies are needed to strengthen this argument. Case-control and cohort studies show that several markers have a higher sensitivity to detect bladder cancer. However, cytology is the superior marker in terms of specificity, although some markers in limited numbers of studies have shown specificity equivalent to that of cytology. Our panel believes that several bladder tumor markers are more accurate in detecting bladder cancer than prostate-specific antigen (PSA) is in detecting prostate cancer. However, bladder tumor markers are held to a higher standard than PSA. Therefore, use of bladder tumor markers in the management of patients with bladder cancer will require the willingness of both urologists and clinicians to accept them.

Prognostic markers for bladder cancer: International Consensus Panel on bladder tumor markers.

The International Consensus Panel on cytology and bladder tumor markers evaluated markers that have the ability to predict tumor recurrence, progression, development of metastases, or response to therapy or patient survival. This article summarizes those findings. The panel mainly reviewed articles listed in PubMed on various prognostic indicators for bladder cancer. Based on these studies, most of which were case-control retrospective studies, various prognostic indicators were classified into 6 groups: (1) microsatellite-associated markers, (2) proto-oncogenes/oncogenes, (3) tumor suppressor genes, (4) cell cycle regulators, (5) angiogenesis-related factors, and (6) extracellular matrix adhesion molecules. The panel concluded that although certain markers, such as Ki-67 and p53, appear to be promising in predicting recurrence and progression of bladder cancer, the data are still heterogeneous. The panel recommends that identifying definitive criteria for test positivity, a clearly defined patient population, standardization of techniques used to evaluate markers, and clearly specified endpoints and statistical methods will help to bring accurate independent prognostic indicators into the clinical management of patients with bladder cancer.

Handling and pathology reporting of radical prostatectomy specimens.

Proper examination of radical prostatectomy (RP) specimens by the pathologists is critical in accurately determining the prediction of patient outcome. The pathology report should include relevant clinical information as well as provide prognostically useful data derived from the evaluation of the RP specimen.

The side effects of Bacillus Calmette-Guerin in the treatment of Ta T1 bladder cancer do not predict its efficacy: results from a European Organisation for Research and Treatment of Cancer Genito-Urinary Group Phase III Trial.

OBJECTIVES: Previous publications have suggested that patients developing local and/or systemic side effects to Bacillus Calmette-Guerin (BCG) have a better clinical result, however it is necessary to determine if toxicity is responsible for improved efficacy. METHODS: After transurethral resection, intravesical instillations of BCG were given during a 6-week induction course followed by 3-weekly maintenance courses at 3, 6, 12, 18, 24, 30 and 36 months. The prognostic importance of delaying or stopping BCG due to local and/or systemic side effects was assessed in 487 patients. RESULTS: Patients with local BCG side effects had a significantly longer time to first recurrence, suggesting that side effects are related to efficacy. However patients with a better outcome remain on study for a longer period of time and receive more BCG, thus increasing their risk to develop side effects. To prove whether toxicity is responsible for improved efficacy, the prognostic importance of toxicity occurring prior to the 6 month instillations was assessed using the landmark method. Neither local nor systemic BCG toxicity prior to 6 months was related to subsequent recurrence. CONCLUSIONS: While a correlation between BCG toxicity and efficacy exists, this study does not confirm that BCG toxicity is actually responsible for an improved outcome.

Maintenance Bacillus Calmette-Guerin for Ta T1 bladder tumors is not associated with increased toxicity: results from a European Organisation for Research and Treatment of Cancer Genito-Urinary Group Phase III Trial.

OBJECTIVES: After transurethral resection, the local and systemic side effects of Bacillus Calmette-Guerin (BCG) instillations were assessed during a 6-week induction course followed by 3 weekly maintenance instillations at 3, 6, 12, 18, 24, 30 and 36 months to determine if BCG toxicity increases over time. METHODS: 487 patients who received BCG in a multicenter phase III trial were included. Side effects were divided into 5 different treatment periods: the first 6 weeks induction, months 3 and 6, month 12, the second year, and the third year. RESULTS: 99 (20.3%) patients stopped BCG due to side effects. 72 (14.8%) stopped due to local side effects, including 59 for BCG induced cystitis, 33 during the first 6 months. 46 (9.4%) stopped due to systemic side effects: 23 due to fever, 19 within 6 months, and 15 due to general malaise, 12 within 6 months. 68% who stopped due to side effects did so during the first 6 months. The percent stopping after 6 months due to local side effects does not increase and actually decreases for systemic side effects. CONCLUSIONS: The majority of local and systemic side effects are seen already during the induction and the first half-year of maintenance. During further maintenance BCG toxicity does not increase and instillations are generally well tolerated.

Gonadotropin-releasing hormone receptors in prostate tissue.

OBJECTIVE: To perform an immunohistochemical analysis of gonadotropin-releasing hormone receptors (GnRH-Rs) in archival prostate tissue. STUDY DESIGN: Thirteen benign prostatic hyperplasia (BPH) specimens from open surgery, 48 radical prostatectomy specimens (30 surgery only and 18 neoadjuvant hormone treatment and surgery) and 14 prostate needle biopsies were examined. The avidin-biotin-peroxidase technique and monoclonal antibody A9E4 against the extracellular domain of GnRH-Rs were employed. Cases with > 5% immunoreactive cells (IR) were considered positive. RESULTS: The epitheliumfrom all 13 cases of BPH was immunoreactive. Most tumor cellsfrom biopsies were IR positive. Twenty-seven of 30 surgery-only specimens were IR positive vs. 8/18 in the surgery and neoadjuvant hormone treatment group. CONCLUSION: GnRH-Rs have been histochemically demonstrated in normal lutenizing hormone/follicle-stimulating hormone pituitary cells. In cell lines LN-CaP and DU-145, Gn-RH-R was identical to that of the pituitary. GnRH-Rs in the prostate can be quite easily assessed immunohistochemically in archival tissue samples, and hormone treatment significantly decreases the immunoreactivity of GnRH-Rs in prostate cancer tissue. This strongly suggests that GnRH agonists bind to BPH and prostate cancer cells.