HER2 expression and gene amplification in pT2a Gleason score 6 prostate cancer incidentally detected in cystoprostatectomies: comparison with clinically detected androgen-dependent and androgen-independent cancer

State of the art and future perspectives of new radionuclides in Nuclear Medicine

This continuing education analyzes recent advances in Nuclear Medicine focused on the development of new radiopharmaceuticals that improve both the diagnosis and treatment of complex diseases. The focus is on teragnosis, which combines diagnosis and treatment by means of pairs of radiopharmaceuticals directed to the same molecular target, which allows the personalization of treatments. This first part specifically reviews the teragnostic pairs copper-64/copper-67, lead-212/lead-203 and scandium-44/scandium-47, highlighting their physical characteristics, methods of production and potential clinical applications. Despite the challenges in their production, their versatility and effectiveness are driving their clinical application in oncology and other diseases. The text also addresses the development of new radiopharmaceuticals and their impact on precision medicine, pointing out future directions and opportunities for research in this field.

Clinicopathologic characteristics and outcomes of prostate cancer incidentally discovered at the time of radical cystoprostatectomy: a population-based cohort study

OBJECTIVE

This study aimed to comprehensively analyze the clinical characteristics and prognosis of patients with concomitant bladder cancer (BCa) and prostate cancer (PCa) using a large population-based database.

METHODS

Within the Surveillance, Epidemiology, and End Results (SEER) database (2000-2019), the authors identified patient with concomitant PCa at the time of radical cystoprostatectomy (RCP). Logistic regression and propensity score matching (PSM) analyses were employed to identify risk factors and mitigate confounders, respectively. Kaplan-Meier survival curves were used to estimate cancer-specific survival (CSS).

RESULTS

A total of 14 199 BCa patients undergoing RCP were identified, with 28.8% incidentally discovered to have concurrent PCa. Among them, 89.9% exhibited organ-confined (T1-2) PCa. An increased risk of concomitant tumors was observed among older age, white race, and high tumor grade of BCa. Survival analysis revealed no significant difference in CSS between patients with BCa alone and those with concurrent PCa (5-year CSS rate: 71.3 vs. 67.2%, P =0.076). Subgroup analysis and multivariable analysis, however, indicated that concurrent high-risk PCa adversely impacted survival (5-year CSS rate: 71.3 vs. 63.4%, HR 1.27, 95% CI: 1.01-1.58, P =0.038) compared to solitary BCa. Notably, the presence of low/intermediate-risk PCa did not affect survival outcomes ( P =0.584).

CONCLUSION

In conclusion, incidentally discovered PCa in RCP specimens is frequent and characterized by organ-confined presentation, lower PSA levels, and Gleason scores. Patients with concurrent high-risk PCa have a worse prognosis compared to those with solitary BCa, while the presence of low/intermediate-risk PCa does not influence oncological prognosis.

Her2 Expression in Circulating Tumor Cells Is Associated with Poor Outcomes in Patients with Metastatic Castration-Resistant Prostate Cancer

HER2-dependent signaling may support the development of metastatic castration-resistant prostate cancer (mCRPC) by activating androgen receptor signaling through ligand-independent mechanisms. From 41 mCRPC patients (including 31 treated with Androgen Receptor Signaling Inhibitors [ARSI]), Circulating Tumor Cells (CTCs) were prospectively enriched with AdnaTest platform and analyzed with a multiplexed assay for HER2 and AR-V7 mRNA expression. Then, we evaluated the impact of HER2 expression on PSA-response, Progression Free Survival (PFS) and Overall Survival (OS). HER2 expression was detected in CTCs of 26 patients (63%). Although PSA response was similar regardless of HER2 status, patients with HER2 positive CTCs had shorter PSA-PFS (median: 6.2 months versus 13.0 months, p = 0.034) and radiological-PFS (6.8 months versus 25.6 months, p = 0.022) than patients without HER2 expression. HER2 expression was also associated with a shorter OS (22.7 months versus not reached, p = 0.05). In patients treated with ARSI, multivariate analyses revealed that the prognostic impact of HER2 status on PSA-PFS was independent of AR-V7 expression and of the detection of CTCs by an AdnaTest. We showed for the first time the poor prognostic value of HER2 expression in CTCs from patients with mCRPC. The therapeutic interest of targeting this actionable pathway remains to be explored.

203/212Pb Theranostic Radiopharmaceuticals for Image-guided Radionuclide Therapy for Cancer

Receptor-targeted image-guided Radionuclide Therapy (TRT) is increasingly recognized as a promising approach to cancer treatment. In particular, the potential for clinical translation of receptor-targeted alpha-particle therapy is receiving considerable attention as an approach that can improve outcomes for cancer patients. Higher Linear-energy Transfer (LET) of alpha-particles (compared to beta particles) for this purpose results in an increased incidence of double-strand DNA breaks and improved-localized cancer-cell damage. Recent clinical studies provide compelling evidence that alpha-TRT has the potential to deliver a significantly more potent anti-cancer effect compared with beta-TRT. Generator-produced 212Pb (which decays to alpha emitters 212Bi and 212Po) is a particularly promising radionuclide for receptor-targeted alpha-particle therapy. A second attractive feature that distinguishes 212Pb alpha-TRT from other available radionuclides is the possibility to employ elementallymatched isotope 203Pb as an imaging surrogate in place of the therapeutic radionuclide. As direct non-invasive measurement of alpha-particle emissions cannot be conducted using current medical scanner technology, the imaging surrogate allows for a pharmacologically-inactive determination of the pharmacokinetics and biodistribution of TRT candidate ligands in advance of treatment. Thus, elementally-matched 203Pb labeled radiopharmaceuticals can be used to identify patients who may benefit from 212Pb alpha-TRT and apply appropriate dosimetry and treatment planning in advance of the therapy. In this review, we provide a brief history on the use of these isotopes for cancer therapy; describe the decay and chemical characteristics of 203/212Pb for their use in cancer theranostics and methodologies applied for production and purification of these isotopes for radiopharmaceutical production. In addition, a medical physics and dosimetry perspective is provided that highlights the potential of 212Pb for alpha-TRT and the expected safety for 203Pb surrogate imaging. Recent and current preclinical and clinical studies are presented. The sum of the findings herein and observations presented provide evidence that the 203Pb/212Pb theranostic pair has a promising future for use in radiopharmaceutical theranostic therapies for cancer.

Correlation of Gleason Grading and Prognostic Immunohistochemistry Markers (Human Epidermal Growth Factor Receptor 2/neu and Androgen Receptor) in Prostatic Core Needle Biopsy: A Study in a Tertiary Care Center

Background: Worldwide prostate cancer is the most common cause of cancer and the second leading cause of cancer death among men. Transrectal ultrasound-guided core needle biopsies are the diagnostic modalities which help in proper categorization and grading of prostatic carcinoma, thus facilitating individualized treatment. These biopsies are the primary source for performance of additional diagnostic immunohistochemical testing for basal cell-associated markers to rule out the morphological mimicker and prognostic markers such as androgen receptor (AR) and human epidermal growth factor receptor 2 (HER2)/neu. Materials and Methods: A prospective, observational study was conducted in the department of pathology in collaboration with department of urosurgery of a tertiary care hospital. One hundred and nineteen patients diagnosed with prostatic nodules were included in this study. Values of serum prostate-specific antigen were recorded. Tissue for histopathological study was obtained in the form of core needle biopsy, and Gleason grade was calculated in all malignant cases. Immunohistochemistry for p63 and alpha-methylacyl-CoA racemase was performed as an additional test in premalignant cases. Prognostication of the prostate cancer cases was done using AR and HER2/neu. Results: A total of 119 cases aged between 20 and 90 years were included in this study. Malignant lesions reveal an increase in the percentage of AR staining in comparison to the benign glandular structure. The Gleason score with higher value (8–9) showed increased expression of HER2/neu receptor. Conclusion: Critical histopathological analysis of core needle biopsy along with immunohistochemical evaluation maximizes the diagnostic accuracy in prostate cancer cases and also helps in prognosis assessment.

ErbB-2 signaling in advanced prostate cancer progression and potential therapy

Currently, prostate cancer (PCa) remains the most commonly diagnosed solid tumor and the second leading cause of cancer-related deaths in US men. Most of these deaths are attributed to the development of castration-resistant (CR) PCa. ErbB-2 and ErbB family members have been demonstrated to contribute to the progression of this lethal disease. In this review, we focus on updating the role of ErbB-2 in advanced PCa progression and its regulation, including its regulation via ligand activation, miRNAs and protein phosphorylation. We also discuss its downstream signaling pathways, including AKT, ERK1/2 and STATs, involved in advanced PCa progression. Additionally, we evaluate the potential of ErbB-2, focusing on its protein hyper-phosphorylation status, as a biomarker for aggressive PCa as well as the effectiveness of ErbB-2 as a target for the treatment of CR PCa via a multitude of approaches, including orally available inhibitors, intratumoral expression of cPAcP, vaccination and immunotherapy.

Three-dimensional proton magnetic resonance spectroscopy and diffusion-weighted imaging in the differentiation of incidental prostate carcinoma from benign prostate hyperplasia

The present study evaluated three-dimensional proton magnetic resonance spectroscopy (MRS) and diffusion-weighted imaging (DWI) features in differentiating incidental prostate carcinoma (IPCa) and benign prostate hyperplasia (BPH) in the central gland of the prostate. The clinical and imaging data of 9 patients with IPCa, 118 patients with BPH [including those with glandular hyperplasia (GH), stromal hyperplasia (SH) and mixed hyperplasia (MH)], were retrospectively analyzed. The mean (choline + creatine)/citrate (CC/C) value of 3D MRS, the apparent diffusion coefficient (ADC) value and the minimal ADC value of DWI were compared between carcinoma and non-carcinoma tissues. The mean CC/C values were 1.04±0.28, and 1.09±0.58 in IPCa and BPH, respectively (t=-0.205, P=0.838). No significant difference in CC/C values (χ²=2.595, P=0.458) could be detected between IPCa, GH, SH and MH groups. The ADC values of the central gland only differed between IPCa (1.48±0.18) ×10^-3 and GH (1.60±0.16) ×10^-3 mm²/sec (P=0.037). The minimal ADC values were similar between IPCa (1.15±0.10) ×10^-3 and BPH (1.14±0.11) ×10^-3 mm²/sec, no significant differences could be detected between IPCa and GH (P=0.930), IPCa and SH (P=0.192), and IPCa and MH (P=0.544). Although the ADC values of the central gland of the prostate differed between IPCa and GH, the findings of the present study therefore indicate that combining 3D MRS with DWI cannot potentially improve the detection of IPCa.

Radioimmunotherapy for Prostate Cancer--Current Status and Future Possibilities

Prostate cancer (PCa) is one of the most common cancers in men and is the second leading cause of cancer-related deaths in the USA. In the United States, it is the second most frequently diagnosed cancer after skin cancer, and in Europe it is number one. According to the American Cancer Society, approximately 221,000 men in the United States would be diagnosed with PCa during 2015, and approximately 28,000 would die of the disease. According to the International Agency for Research on Cancer, approximately 345,000 men were diagnosed with PCa in Europe during 2012, and despite more emphasis placed on early detection through routine screening, 72,000 men died of the disease. Hence, the need for improved therapy modalities is of utmost importance. And targeted therapies based on radiolabeled specific antibodies or peptides are a very interesting and promising alternative to increase the therapeutic efficacy and overall chance of survival of these patients. There are currently several preclinical and some clinical studies that have been conducted, or are ongoing, to investigate the therapeutic efficacy and toxicity of radioimmunotherapy (RIT) against PCa. One thing that is lacking in a lot of these published studies is the dosimetry data, which are needed to compare results between the studies and the study locations. Given the complicated tumor microenvironment and overall complexity of RIT to PCa, old and new targets and targeting strategies like combination RIT and pretargeting RIT are being improved and assessed along with various therapeutic radionuclides candidates. Given alone or in combination with other therapies, these new and improved strategies and RIT tools further enhance the clinical response to RIT drugs in PCa, making RIT for PCa an increasingly practical clinical tool.

Possible Role of HER-2 in the Progression of Prostate Cancer from Primary Tumor to Androgen Independence

BACKGROUND

The expression of HER-2 in prostate cancer has been linked to disease progression. We analysed the presence of HER-2 expression in primary tumors in men undergoing radical prostatectomy, its association with clinical and pathological findings, and its expression in secondary circulating prostate cells (CPCs) during follow up, as well as links with biochemical failure and the effects of androgen blockade.

MATERIALS AND METHODS

Consecutive men undergoing radical prostatectomy for histologically confirmed prostate cancer were analyzed. HER-2 expression in the primary tumor was assessed using the HercepTest®, CPCs were identified from blood samples using standard immunocytochemistry with anti-PSA and positive samples with the HercepTest® to determine HER-2 expression. The influence of HER-2 expression on the frequency of biochemical failure and effects of androgen blockade was determined.

RESULTS

144 men with a mean age of 64.8±10.3 years participated, with a median follow up of 8.2 years. HER-2 was expressed in 20.8% of primary tumors; it was associated with vascular infiltration and older age, but not with other clinical pathological findings. Some 40.3% of men had secondary CPCs detected, of which 38% expressed HER-2. Men CPC (+) had a higher frequency of biochemical failure, but there was no difference in HER-2 expression of CPCs with the frequency of biochemical failure. After androgen blockade, men with HER-2 (+) positive secondary CPCs had a higher frequency of disease progression to castrate resistant disease.

CONCLUSIONS

HER-2 plays a dual role in the progression of prostate cancer; firstly it may increase the potential of tumor cells to disseminate from the primary tumor via the blood by increasing vascular infiltration. In the presence of androgens, there is no survival advantage of expressing HER-2, but once biochemical failure has occurred and androgen blockade started, HER-2 positive cells are resistant to treatment, survive and grow leading to castration resistant disease.

Incidental prostate cancer diagnosed at radical cystoprostatectomy for bladder cancer: disease-specific outcomes and survival

Background

The current standard of care for men with muscle-invasive bladder cancer is radical cystoprostatectomy (RCP). One-third of RCP specimens demonstrate incidental prostate cancer, primarily reported in small series with limited follow-up. The aim of this study is to report mature outcomes, including patterns of failure and disease-specific recurrence rates, and survival, for a large cohort of men with incidental prostate cancer at RCP performed at a tertiary referral center.

Methods

This retrospective study describes cancer control and survival rates for men who underwent RCP for bladder cancer and were found incidentally to have prostate cancer. Analysis of patient-, tumor-, and treatment-specific factors were analyzed for association with disease control and survival endpoints.

Results

Between 2002 and 2010, 94 patients with incidental discovery of prostate cancer postRCP were identified for inclusion in this study. Forty-five patients (45%) underwent RCP for recurrent (rather than initial presentation of) bladder carcinoma. At a median follow-up of 40.3 months (71.2 months for survivors; range, 8.9–155.5 months), 42 patients were alive without recurrence and 52 patients had died (25 associated with disease). The estimated 5-year bladder cancer disease-free, urinary tract malignancy disease-free, and prostate specific antigen (PSA) relapse-free survivals were 76% [95% confidence interval (CI), 65–84%], 64% (52–74%), and 97% (79–100%), respectively. The estimated 5-year urinary tract malignancy-specific and overall survivals were 61% (49–71%) and 52% (41–62%), respectively. Univariate analysis demonstrated associations between pathologic T/N-stage and nodal ratio with bladder cancer disease-free, urinary tract malignancy disease-specific, and overall survivals, with patient age at diagnosis as an additional adverse factor associated with overall survival. Multivariate analysis confirmed pN-stage and age as independently associated with worse survival.

Conclusion

For men undergoing RCP for bladder cancer, the present study suggests that incidentally discovered prostate cancers, irrespective of pathologic stage, Gleason score, or clinical significance, do not impact 5-year disease control or survival outcomes.

ErbB-2 signaling plays a critical role in regulating androgen-sensitive and castration-resistant androgen receptor-positive prostate cancer cells

While androgen deprivation therapy (ADT) reduces tumor burden, autocrine growth factor loops such as human epidermal growth factor receptor 2 (HER2/ErbB-2/neu) have been proposed to contribute to prostate cancer (PCa) survival and relapse. However, the role of ErbB-2 in regulating androgen-sensitive (AS) and castration-resistant (CR) cell proliferation remains unclear. Here, we determined the role of ErbB-2 in PCa progression and survival under steroid-reduced conditions using two independent PCa cell progression models. In AR-positive androgen-independent (AI) PCa cells that exhibit the CR phenotype, ErbB-2 was constitutively activated, compared to corresponding AS PCa cells. In AS LNCaP C-33 cells, androgen-induced ErbB-2 activation through ERK1/2 mediates PCa cell proliferation. Further, the ErbB-2-specific but not EGFR-specific inhibitor suppresses basal and androgen-stimulated cell proliferation and also blocks ERK1/2 activation. ErbB-2 ectopic expression and cPAcP siRNA transfection of LNCaP C-33 cells each increases ErbB-2 tyrosine phosphorylation, correlating with increased AI PSA secretion and cell proliferation. Conversely, trapping ErbB-2 by transfected endoplasmic reticulum-targeting ScFv5R expression vector abolished DHT-induced LNCaP C-33 cell growth. Moreover, inhibition of ErbB-2 but not EGFR in AI LNCaP C-81 and MDA PCa2b-AI PCa cells significantly abolished AI cell growth. In contrast to androgens via ErbB-2/ERK1/2 signaling in AS PCa cells, the inhibition of ErbB-2 abrogated AI cell proliferation by inhibiting the cell survival protein Akt in those AI cells. These results suggest that ErbB-2 is a prominent player in mediating the ligand-dependent and -independent activation of AR in AS and AI/CR PCa cells respectively for PCa progression and survival.

Overexpression of HER-2/neu in patients with prostatic adenocarcinoma

BACKGROUND

Prostatic adenocarcinoma is one of the main causes of cancer death, and its timely diagnosis and preventing its progression dramatically helps improve life indexes. Given the high disease recurrence rate, today, research is more inclined toward exploring causes of recurrence and development, and innovation of modern treatment methods. Several studies have explored over-expression of human epidermal growth factor receptor 2 (HER-2/neu) in prostatic cancer so far, with different results. Thus, it was decided to investigate HER-2/neu overexpression in patients with prostatic adenocarcinoma in Iran.

MATERIALS AND METHODS

A sample size of 40 patients with prostate cancer entered the study, using a cross-sectional, non-randomized sampling method. Parameters studied included patient age at surgery, Gleason score, serum prostatic specific antigen (PSA) before surgery, and positive sample rate after immunohistochemical staining to investigate HER-2/neu overexpression.

RESULTS

In terms of HER-2/neu receptor staining rate, of 40 slides, 16 (40%) scored 0, 13 (32.5%) 1+, 7 (17.5%) 2+, and 4 (10%) 3+. In total 27.5% of slides showed HER-2/neu overexpression. In terms of age, an inverse correlation was found (-0.181), but without significance (p=0.263). In terms of serum PSA, the correlation coefficient was 0.449 (p=0.004). With respect to Gleason score, the coefficient was 0.190 (p=0.240).

CONCLUSIONS

In this study, HER-2/neu overexpression occurred in 27.5% of prostate cancer cases, which is a relatively high figure, compared to similar studies elsewhere. While, we failed to reveal any relationship between HER-2/neu expression status with progression and prognosis of disease, it was demonstrated that the serum PSA level was significantly higher in cases with increased receptor expression.

[Prognostic influence of prostate gland invasion by bladder tumour and/or prostate cancer in cystoprostatectomy specimen: a review]

INTRODUCTION

Cystoprostatectomy (CPT) is the gold standard surgical treatment for muscle invasive bladder cancer (MIBC). In certain cases, MIBC can invade the prostate gland and/or a prostate cancer (PCa) can be discovered fortuitously on the pathologic specimen. The aim of the current study was to report the prognostic influence of PCa in patients who underwent a CPT for MIBC.

MATERIALS AND METHODS

A systematic review of the scientific literature was achieved in the Pubmed database, using the following keywords: prostatic neoplasm; urinary bladder neoplasm; cystectomy; surgery; recurrence; prognosis; survival. Clinical cases and series of less than five cases were deliberately excluded herein.

RESULTS

Overall, ten studies published between 2004 and 2011 and involving 2196 patients were selected. Only retrospective studies of low level of evidence (NP 4) were available. The incidence of neoplastic invasion of the prostate gland by MIBC ranged from 25 to 48%. Preoperative predictors were multiple BC, recurrent, location in the trigone and existence of CIS. Overall survival at 3 years was significantly affected by the invasion of the prostate gland (pT4a) in these patients. The incidence of PCa discovered incidentally pathologic specimen CPT ranged from 14 to 49%. Only age was found as a positive predictor. The diagnosis of PCa did not influence survival of patients with MIBC and no specific PCa adjuvant treatment was systematically advocated.

CONCLUSION

Fortuitous diagnosis of PCa and/or neoplastic invasion of the prostatic gland by BC on CPT specimen is not uncommon but this is variable across studies, depending on the quality of the pathological analysis. The invasion of the prostate gland by MIBC is a serious situation (pT4a) and linked with a poor prognosis. In case of concomitant PCa and MIBC, the prognosis is much more related to the natural history of the bladder tumour.

Is there a role for prostate tumour overexpressed-1 in the diagnosis of HGPIN and of prostatic adenocarcinoma? A comparison with alpha-methylacyl CoA racemase

Prostate Tumour Overexpressed-1 (PTOV1) was recently identified as a novel gene and protein during a differential display screening for genes overexpressed in prostate cancer (PCa). Alpha-Methyl-CoA racemase (AMACR) mRNA was identified as being overexpressed in PCa. PTOV1 and racemase were immunohistochemically evaluated in PCa, high-grade prostatic intraepithelial neoplasia (HGPIN), atrophy and normal-looking epithelium (NEp) in 20 radical prostatectomies (RPs) with pT2a Gleason score 6 prostate cancer with the aim of analyzing the differences in marker expression between PTOV1 and AMACR. The level of expression of PTOV1 and AMACR increased from NEp and atrophy through HGPIN, away from and adjacent to prostate cancer, to PCa. With the ROC curve analysis the overall accuracy in distinguishing PCa vs HGPIN away from and adjacent to cancer was higher for AMACR than for PTOV1. In conclusion, AMACR can be considered a more accurate marker than PTOV1 in the identification of HGPIN and of PCa. However, PTOV1 may aid in the diagnosis of PCa, at least to supplement AMACR as another positive marker of carcinoma and to potentially increase diagnostic accuracy.

Cell-based quantification of molecular biomarkers in histopathology specimens

AIMS

To investigate the use of a computer-assisted technology for objective, cell-based quantification of molecular biomarkers in specified cell types in histopathology specimens, with the aim of advancing current visual estimation and pixel-level (rather than cell-based) quantification methods.

METHODS AND RESULTS

Tissue specimens were multiplex-immunostained to reveal cell structures, cell type markers, and analytes, and imaged with multispectral microscopy. The image data were processed with novel software that automatically delineates and types each cell in the field, measures morphological features, and quantifies analytes in different subcellular compartments of specified cells.The methodology was validated with the use of cell blocks composed of differentially labelled cultured cells mixed in known proportions, and evaluated on human breast carcinoma specimens for quantifying human epidermal growth factor receptor 2, estrogen receptor, progesterone receptor, Ki67, phospho-extracellular signal-related kinase, and phospho-S6. Automated cell-level analyses closely matched human assessments, but, predictably, differed from pixel-level analyses of the same images.

CONCLUSIONS

Our method reveals the type, distribution, morphology and biomarker state of each cell in the field, and allows multiple biomarkers to be quantified over specified cell types, regardless of their abundance. It is ideal for studying specimens from patients in clinical trials of targeted therapeutic agents, for investigating minority stromal cell subpopulations, and for phenotypic characterization to personalize therapy and prognosis.

HER2 overcomes PTEN (loss)-induced senescence to cause aggressive prostate cancer

Prostate cancer (CaP) is the most common cancer among adult men in the Western world. Better insight into its tumor-activating pathways may facilitate the development of targeted therapies. In this study, we show that patients who develop prostate tumors with low levels of PTEN and high levels of HER2/3 have a poor prognosis. This is functionally relevant, as targeting Her2 activation to the murine prostate cooperates with Pten loss and drives CaP progression. Mechanistically, this is associated with activation of the MAPK pathway and abrogation of the Pten loss-induced cellular senescence program. Importantly, inhibition of MEK function strongly suppressed proliferation within these tumors by restoring the Pten loss-induced cellular senescence program. Taken together, these data suggest that stratification of CaP patients for HER2/3 and PTEN status could identify patients with aggressive CaP who may respond favorably to MEK inhibition.

Immunohistochemical expression of prostate tumor overexpressed 1 in cystoprostatectomies with incidental and insignificant prostate cancer. Further evidence for field effect in prostatic carcinogenesis

Prostate tumor overexpressed 1 was recently identified as a novel gene and protein during a differential display screening for genes overexpressed in prostate cancer. It has been suggested that overexpression of prostate tumor overexpressed 1 can contribute to the proliferative status of prostate tumor cells and, thus, to their biologic behavior. Prostate tumor overexpressed 1 and Ki-67 were immunohistochemically evaluated in prostate cancer, high-grade prostatic intraepithelial neoplasia, and normal-looking epithelium in 20 cystoprostatectomies and 20 radical prostatectomies with pT2a Gleason score 6 prostate cancer. The aim was to see whether there were differences in marker expression between cystoprostatectomies and radical prostatectomies. The proportions of prostate tumor overexpressed 1- and Ki-67-positive cells in the cystoprostatectomies and radical prostatectomies increased from normal-looking epithelium through high-grade prostatic intraepithelial neoplasia, away from and adjacent to prostate cancer, to prostate cancer. Prostate tumor overexpressed 1 expression in prostate cancer in cystoprostatectomies was lower than in radical prostatectomies, the differences being significant; there were significant differences in Ki-67 indices. In conclusion, our findings related to prostate tumor overexpressed 1 expression in high-grade prostatic intraepithelial neoplasia, evaluated adjacent and away from prostate cancer, and in incidental and clinical cancers give further support to the concept of field effect in prostatic carcinogenesis as well as to differences in the process of prostatic carcinogenesis between cystoprostatectomies and radical prostatectomies.

Prognostic significance of focal neuroendocrine differentiation in prostate cancer: cases with autopsy-verified cause of death

AIMS

This study was designed to evaluate the prognostic significance of focal chromogranin A (cgA) expression in prostate cancer in a series of cases with autopsy-verified cause of death.

METHODS AND RESULTS

Seventy seven autopsy-verified cases of prostate cancer were identified, 41 cases with metastatic disease and 36 with nonmetastatic disease at autopsy. Immunohistochemical analysis for cgA was performed in 40 cases on the archived diagnostic biopsies taken during the patients' lifetime. After exclusion of a single case of carcinoid tumor, 14 of the 18 (78%) metastatic and none of the 21 (0%) nonmetastatic tumors showed focal neuroendocrine differentiation (NED). The Gleason score and focal cgA expression further increased the accuracy of the prediction of the outcome, as all the cases with focal NED associated with high Gleason score had metastatic disease in contrast to cases without cgA-expression and low Gleason score, all of which were non-metastatic.

CONCLUSIONS

Focal NED seems to be a powerful negative prognostic parameter in prostate adenocarcinomas. The outcome of the disease in prostate cancer can be accurately predicted based on focal NED of the tumor cells either alone or in combination with Gleason score.

Matriptase is involved in ErbB-2-induced prostate cancer cell invasion

Deregulation of both ErbB-2 signaling and matriptase activity has been associated with human prostate cancer (PCa) progression. In this communication, we investigated the roles of both ErbB-2 signaling in matriptase zymogen activation and matriptase in ErbB-2-induced PCa malignancy. In a human PCa cell progression model, we observed that advanced PCa C-81 LNCaP cells exhibited an aggressive phenotype with increased cell migration and invasion capacity; these cells concurrently showed both enhanced ErbB-2 phosphorylation and increased matriptase zymogen activation compared with parental C-33 LNCaP cells. Moreover, ErbB2 activation, both ligand-dependent (eg, epidermal growth factor treatment) and ligand-independent (eg, overexpression), was able to induce matriptase zymogen activation in this cell line. Inhibition of ErbB-2 activity by either the specific inhibitor, AG825, in epidermal growth factor-treated C-33 LNCaP cells or ErbB-2 knockdown in C-81 LNCaP cells, reduced matriptase activation. These observations were confirmed by similar studies using both DU145 and PC3 cells. Together, these data suggest that ErbB-2 signaling plays an important role in matriptase zymogen activation. ErbB-2-enhanced matriptase activation was suppressed by a phosphatidylinositol 3-kinase inhibitor (ie, LY294002) but not by a MEK inhibitor (ie, PD98059). Suppression of matriptase expression by small hairpin RNA knockdown in ErbB-2-overexpressing LNCaP cells dramatically suppressed cancer cell invasion. In summary, our data indicate that ErbB-2 signaling via the phosphatidylinositol 3-kinase pathway results in up-regulated matriptase zymogen activity, which contributes to PCa cell invasion.

Immunohistochemical expression and localization of somatostatin receptor subtypes in prostate cancer with neuroendocrine differentiation

The aim of the study is to examine the tissue expression and localization of the somatostatin receptors (SSTRs) in prostate cancer (PCa) with neuroendocrine (NE) differentiation. The five SSTR subtypes (SSTR1 to 5) were evaluated immunohistochemically in the secretory cells of normal-looking epithelium (Nep), high-grade prostatic intraepithelial neoplasia (HGPIN) and PCa in 20 radical prostatectomies (RPs) with Gleason score 3+3=6 acinar PCa; 20 RPs with GS 4+4=8 and 4+5=9 PCa; and 20 RPs with PCa with NE differentiation. The basal cells were evaluated in Nep and HGPIN. In all groups the stromal smooth muscle and endothelial cells were also analyzed. Concerning the secretory cells, (i) the greatest mean proportions of cells with strong cytoplasmic staining in PCa were seen for SSTR2, mainly in the group of RP with NE differentiation, and for SSTR4 in all three groups; the mean values in HGPIN were intermediate between Nep and PCa; (ii) Membrane staining was seen for SSTR3 and SSTR4; the mean percentages of positive cells, higher in SSTR3 than in SSTR4, decreased from Nep to HGPIN and PCa in all three RP groups; in the latter two, the mean percentages were similar; and (iii) Nuclear staining was seen with SSTR4 and SSTR5; for SSTR4, the mean percentages in the PCa of the three groups were higher than in HGPIN and Nep, the highest proportion being with PCa with NE differentiation. Concerning the basal cells, in Nep the mean proportions of cells with strong staining intensity were greater for SSTR1 and SSTR3 than for the other subtypes, the lowest being with SSTR2; in HGPIN the highest mean propositions of positive cells was with SSTR3, the proportions in the three RP groups being similar. Concerning the stromal smooth muscle and endothelial cells, the highest mean values being in SSTR1 and the lowest in SSTR5; for the former subtype the highest proportion of endothelial cells with strong intensity was seen in the RP NE group. In conclusion, this immunohistochemical study expands our knowledge on the expression and localization of five SSTRs in the various tissue components in the prostate with PCa with NE differentiation, compared with conventional PCa. Typing somatostatin receptor expression in NE tumours could be of relevance to target somatostatin analogue-based diagnostic approach and treatment.

Low level HER2 overexpression is associated with rapid tumor cell proliferation and poor prognosis in prostate cancer

PURPOSE

The HER2 oncogene is involved in the biology of many different tumor types and serves as a prognostic marker and a therapeutic target in breast cancer. In contrast to breast cancer, studies on Her2 overexpression and gene amplification in prostate cancer have yielded different results. The purpose of this study was to learn more on the prevalence and clinical significance of HER2 amplification and overexpression in prostate cancer.

EXPERIMENTAL DESIGN

A tissue microarray containing >2,000 prostate cancers with follow-up data was used. Tissue microarray sections were analyzed on protein and DNA level using two different antibodies (HercepTest, DAKO; Novocastra NCL-CB11) and fluorescence in situ hybridization.

RESULTS

Immunohistochemical analyses showed highly similar results for both antibodies. Detectable Her2 immunostaining was observed in 17.2% for the HercepTest and in 22.5% for the Novocastra antibody with the vast majority of cases showing 1+ or 2+ staining. For both antibodies (HercepTest/Novocastra), significant associations were found between positive staining and high Gleason grade (P < 0.0001, both), advanced pT stage (P < 0.0001/P = 0.0015), rapid tumor cell proliferation (P = 0.0004/P = 0.0071), and tumor recurrence (P < 0.0001, both). HER2 amplification was only found in 1 of 2,525 analyzable cases (0.04%).

CONCLUSIONS

Low-level Her2 overexpression occurs at relevant frequency in prostate cancer and in the absence of gene amplification. Increased Her2 expression may potentially lead to an aggressive behavior of tumor cells through the stimulation of tumor cell proliferation because Her2 staining was shown to be significantly associated with Ki67 labeling index. These data argue for reconsidering anti-Her2 therapy, possibly with modified approaches.

Immunohistochemical Expression of Prostate Stem Cell Antigen in Cystoprostatectomies with Incidental Prostate Cancer

High expression of Prostate Stem Cell Antigen (PSCA) has been shown to be associated with adverse prognostic features in clinically-diagnosed prostate cancer. The aim of this study is to analyze PSCA expression in cystoprostatectomies with incidental prostate carcinoma (PCa). PSCA expression was evaluated immunohistochemically in normal-looking epithelium (NEp), high-grade prostatic intraepithelial neoplasia (HGPIN) and pT2a Gleason score 6 acinar adenocarcinoma. The evaluation was carried out on 20 cystoprostatectomies (CyPs) with incidental PCa from men with bladder urothelial carcinoma (UC), and 20 radical prostatectomies (RPs) with hormonally untreated PCa from men with clinically detected PCa. Ki-67 was also investigated. The percentages of PSCA positive cells in HGPIN were significantly higher than in NEp (NEp: CyP, mean 2.92% ± standard deviation 6.26%; RP, 3.5% ± 6.46%. HGPIN: CyP, 13.67% ± 12.78%; RP, 14.67% ± 11.34%) (p<0.001). The proportions of positive cells in PCa were greater than in HGPIN (CyP, 20.25% ± 15.96%; RP, 22.58% ± 13.67%) (p0.001). For Ki-67 labeling, the proportions of positive nuclei in the CyPs significantly increased from NEp through HGPIN to PCa. A similar trend was seen in the RPs. In the CyPs the percentages of PSCA and Ki67 positive cells were lower than in the RPs, the differences between the CyP and RP compartments being not statistically significant. Our findings suggest that PSCA is a marker associated with neoplastic transformation of prostate cells, both in CyPs and RPs. However, there are no significant differences between CyPs with incidental prostate carcinoma and RPs with clinically diagnosed cancer.

Bicalutamide demonstrates biologic effectiveness in prostate cancer cell lines and tumor primary cultures irrespective of Her2/neu expression levels

OBJECTIVES

To evaluate the role of Her2/neu as a molecular marker predictive of the treatment response to bicalutamide in prostate cancer (PCa).

METHODS

Four PCa cell lines with graded Her2/neu expression levels and 63 primary tumor cultures derived from men with PCa and selected according to Her2/neu tumor levels were used. Primary tumor cultures and PCa cell lines were treated with bicalutamide (0.1-10 microM) in the presence of dehydrotestosterone (10(-12) M) for 4 days. The presence of a significant correlation between Her2/nue expression and drug efficacy was used to define the role of Her2/neu as molecular predictor of bicalutamide effectiveness. As an indicator of drug effectiveness we used the concentration that inhibits 50% values determined after bicalutamide treatment.

RESULTS

After bicalutamide treatment, no significant differences in the concentration that inhibits 50% were found among the different tumor cell lines (P = .081). In this experimental model, the correlation analysis suggested that the effectiveness of this drug was not influenced by Her2/neu levels (r = 0.053, P = .823). In primary cultures with high Her2/neu levels (43 tumor cultures), the mean value of the concentration that inhibits 50% for bicalutamide was 0.43 +/- 0.13 microM, and in cultures with low Her2/neu levels (20 tumor cultures), the same parameter was 0.5 +/- 0.16 microM (P = .14). The correlation analysis suggested that the effectiveness of this drug was not influenced by Her2/neu levels (r = 0.33, P = .101).

CONCLUSIONS

Our biologic data seem to indicate that the antitumor effect of bicalutamide is independent of Her2/neu levels in preclinical models of PCa. Bicalutamide could be configured as a pharmacologic option to treat patients with high or low levels of Her2/neu.

Her2 crosstalks with TrkA in a subset of prostate cancer cells: rationale for a guided dual treatment

BACKGROUND

To date, no effective therapeutic treatment prevents prostate cancer (PCa) progression to more advanced and invasive disease forms. It has been demonstrated that the simultaneous high expression of p185(HER2) and TrkA might confer a proliferative advantage to PCa cells.

METHODS

In this work we verified the crosstalk between TrkA and Her2 signaling pathways and the effects of a combined treatment with Her2 and TrkA inhibitors.

RESULTS

NGF induced TrkA activation and stimulated cell proliferation of PCa cells. NGF induced also tyrosine phosphorylation of p185(HER2). This event was only partially inhibited by the pan Trk inhibitor, CEP-701 but was strongly blocked by pertuzumab, a humanized antibody blocking Her2 heterodimerization. In presence of NGF, TrkA and Her2 co-precipitated and this was dependent to the relative high cellular levels of TrkA since when cell lysates were immunoprecipitated with an antibody against Her2 the amount of TrkA were proportional to the cellular levels of this receptor. On the contrary when we immunoprecipitated using an antibody against TrkA the amount of Her2 seemed independent to cellular levels of Her2. So, combined treatment between CEP-701 and pertuzumab showed supra-additive effects in cells with higher levels of TrkA and Her2 suggesting once again that this was indicative of a higher response to treatment.

CONCLUSIONS

Our data suggest that the dual inhibition of TrkA and Her2 may be useful in a subset of patients in which TrkA and Her2 are overexpressed and in which the possibility of TrkA and Her2 protein-binding is elevated.

Is incidentally detected prostate cancer in patients undergoing radical cystoprostatectomy clinically significant?

Cystoprostatectomy specimens obtained from patients with bladder cancer provide a unique opportunity to assess the features of silent prostate adenocarcinoma (PCa). The whole-mount prostate sections of 248 totally embedded and consecutively examined radical cystoprostatectomy (RCP) specimens were reviewed to determine the incidence and features of incidentally detected PCa. PCa was considered clinically significant if any of the following criteria were present: total tumor volume, 0.5 cc or more; Gleason grade, 4 or more; extraprostatic extension; seminal vesicle invasion; lymph node metastasis (of PCa); or positive surgical margins. PCa was present in 123 (49.6%) of 248 specimens. Features were as follows: acinar adenocarcinoma, 123 (100.0%); peripheral zone location, 98 (79.7%); pT2a, 96 (78.0%); pT2b, 11 (8.9%); pT2c, 9 (7.3%); pT3a, 5 (4.1%); pT3b, 2 (1.6%); pT4, 0 (0.0%); Gleason score 6 or less, 107 (87.0%); negative margins, 119 (96.7%); pN0 for PCa, 123 (100.0%); and tumor volume less than 0.5 cc, 116 (94.3%). Of the 123 incidentally detected cases of PCa, 100 (81.3%) were considered clinically insignificant. Incidentally detected PCa is frequently observed in RCP. The majority are clinically insignificant.

Putative tissue markers in prostate cancer

A variety of putative prostate cancer markers have been described in human serum, urine, seminal fluid, and histological specimens. These markers exhibit varying capacities to detect prostate cancer and to predict disease course. In order to be considered markers for diagnosis or prognosis of disease course, and to be brought forward for large-scale clinical evaluation, they should fulfill several criteria. Firstly, there should be a biological or therapeutic rationale for choosing the marker, or at least a consistent association with disease presence, disease characteristics such as stage, or disease aggressiveness. Secondly, there should be an assessment of the strength of marker association with disease outcome. Thirdly, the marker should be assessed as an independent predictor in a multivariate analysis.

Elevated levels of HER-2/neu and androgen receptor in clinically localized prostate cancer identifies metastatic potential

BACKGROUND

In this study, we investigated the expression of HER-2/neu and AR in clinically organ-confined prostate cancer to determine whether alterations in these signaling pathways contribute to the development of metastatic disease.

METHODS

HER-2/neu and AR immunoreactivity were evaluated in archived prostatic tissues obtained from 53 men with clinically organ-confined disease who underwent radical prostatectomy. Associations between AR and HER-2/neu immunostaining and disease outcome were determined.

RESULTS

Seventy percent (37/53) of tumors exhibited high levels of HER-2/neu immunostaining and 68% (36/53) of tumors had elevated AR levels. Patients with high levels of both HER-2/neu and AR had the highest rate of PSA failure (56%, 15/27) compared with no PSA failures amongst seven patients with low levels of both HER-2/neu and AR (log rank statistic 7.69, P = 0.021). Concurrent high levels of HER-2/neu and AR expression were significantly associated with high pathological stage (P = 0.027) and development of metastatic disease (P = 0.022).

CONCLUSIONS

These findings support the notion that both the HER-2/neu and AR signaling pathways may contribute to development of metastatic disease. The subset of prostate tumors with increased HER-2/neu and AR levels may benefit from treatment strategies that target both signaling pathways.

Morphological changes induced by androgen blockade in normal prostate and prostatic carcinoma

Maximal androgen blockade (MAB), combining a luteinizing hormone releasing hormone (LHRH) agonist and a pure or non-steroidal anti-androgen, induces significant morphologic changes in the prostate. The tumor volume, density, capsular penetration, and surgical margin involvement are strongly reduced following such treatment. On histology, normal prostate tissue and tumor undergo marked atrophy and shrinkage. Although residual cancer cells are readily identifiable in most cases, they may often be sparse and easily overlooked. The increased Gleason score apparent after MAB is most likely related to fragmentation of acinar structures, and grading is not recommended following MAB. Residual cancer cells show features of lower activity and increased apoptosis. Such therapy-induced changes may be reversible, although occasional clones of cancer cells are apparently not affected and have probably developed resistance. Finally, MAB leads to marked but reversible morphologic changes and reduction in prevalence and extent of prostatic intra-epithelial neoplasia (PIN). Monotherapy using a variety of agents causes comparable but often less extensive changes.

Immunohistochemical Expression of Endothelin-1 and Endothelin-A and Endothelin-B Receptors in High-Grade Prostatic Intraepithelial Neoplasia and Prostate Cancer

OBJECTIVES

To analyze the expression of endothelin-1 (ET-1), endothelin-A receptor (ET-A-R), and endothelin-B receptor (ET-B-R) in incidental prostate cancer in cystoprostatectomies (CyPs), clinically detected hormonally untreated and hormonally treated prostate cancer in radical prostatectomies (RPs), and hormone-independent prostate cancer in transurethral resections of the prostate (TURPs). High-grade prostatic intraepithelial neoplasia (HGPIN) was also investigated.

METHODS

Nineteen CyPs and 44 RPs (25 untreated, 19 treated) with pT2a Gleason score 6 cancer and HGPIN were examined. The study included 9 TURPs with hormone-independent cancer and 8 normal cases from CyPs without prostate cancer and HGPIN. ET-1, ET-A-R, ET-B-R, and the proliferation marker Ki67 were investigated immunohistochemically.

RESULTS

The mean proportion of prostate cancer cells with strong ET-1, ET-A-R, and ET-B-R expression in CyPs was lower (18.5%, 28.0%, and 14.7%, respectively) than in the untreated group (40.7%, 39.7%, and 25.1%) and higher than in treated group (5.0%, 13.9%, and 11.3%). The highest values were in the hormone-independent cancer group (53.9%, 48.9%, 33.3%). The trend in the proportion of HGPIN cells overexpressing ET-1, ET-A-R, and ET-B-R was similar to that in the cancer groups. The values in HGPIN lesions were always slightly greater than those in the cancers. Ki67 expression in HGPIN and prostate cancer in CyPs was lower than in RPs and TURPs.

CONCLUSIONS

Our study showed for the first time that ET-1, ET-A-R, and ET-B-R expression is not limited to the late prostate cancer phases. It is also seen in HGPIN as well as in prostate cancers considered to be clinically insignificant, such as those seen in CyP specimens. Although the series of cases in each group was small, our data may have clinical significance.

Clinicopathologic Features of Prostate Adenocarcinoma Incidentally Discovered at the Time of Radical Cystectomy: An Evidence-Based Analysis

OBJECTIVES

To review all relevant features of incidentally discovered prostate cancer (PCa) in patients undergoing radical cystectomy for bladder cancer: incidence, pathologic characteristics, clinical significance, and implications for its management.

METHODS

A structured literature review through a MEDLINE search was performed.

RESULTS

The frequency of incidentally discovered PCa in cystoprostatectomy specimens is extremely variable because of several factors, particularly the pathology sampling. The relationship among clinically, incidentally, and autopsy-detected cancer is uncertain. The definition of clinically significant cancer varies among published reports and remains inadequate for clinical application. High-grade prostatic intraepithelial neoplasia is a marker for concurrent PCa and the risk depends more on the volume than on its absolute presence. Outcome of patients with unsuspected PCa after cystoprostatectomy relies mostly on the bladder tumor.

CONCLUSIONS

Incidental PCa in patients with bladder cancer is highly variable and with an unclear clinical significance. For those who are candidates for prostate-sparing surgery, it seems reasonable to include a routine prostate biopsy in the standard preoperative work-up irrespective of prostate-specific antigen values. In the absence of sufficient data to make firm recommendations, when PCa is incidentally discovered, PCa surveillance should be part of the follow-up scheme after radical cystectomy.

Molecular staging of prostate cancer in the year 2007

Numerous attempts towards improving patient management by molecular staging have been fruitless so far. No single molecular parameter is routinely analyzed in prostate cancer tissue. This may be partly due to genuine properties of prostate cancer that may make this tumor a difficult target. Furthermore, inherent logistical problems result in a shortage of prostate cancer tissue for research purposes. For the future, it can be hoped that the availability of more powerful molecular techniques in combination with better tissue archives will allow more rapid progress. Powerful DNA array and proteomics methods allow the systematic analysis of virtually all genes of a cancer on the DNA, RNA, and protein level. Although such approaches are sometimes labeled as "fishing expeditions," it cannot be totally disregarded that the simultaneous analysis of all genes has a high likelihood of identifying significant new information. In future, one of the major scientific challenges will be the validation of several potential biomarkers in large enough and clinically well-characterized patient cohorts. In particular, studies on needle core biopsies and hormone refractory cancers are imperatively needed for investigating the natural history of the disease or to discover potential predictive markers for radiation therapy and new therapeutic target genes to answer the clinically most important questions for optimal clinical decision making in prostate cancer patients: which patients will not require local therapy? If local therapy is needed, what is the treatment of choice? What medications should be given if metastases are present?

Amplifications of EGFR gene and protein expression of EGFR, Her-2/neu, c-kit, and androgen receptor in phyllodes tumor of the prostate

Phyllodes tumor of the prostate is a rare neoplasm with an unpredictable clinical behavior. It may undergo early recurrence with sarcomatous transformation or may even metastasize. Because targeted therapies have shown great success against several malignancies, there is hope that these same therapies may show similar promise in the treatment of other neoplasms. This study was undertaken to investigate both amplification of the epidermal growth factor receptor (EGFR) gene by fluorescence in situ hybridization and the overexpression of EGFR, Her-2/neu, CD117 (c-kit), and androgen receptor by immunohistochemical staining in a series of 11 phyllodes tumors of the prostate. In the stromal elements, EGFR gene amplification was present in four of 11 tumors and polysomy chromosome 7 was present in two of 11 tumors. No amplification was present in the epithelial components. Only one of 11 tumors had polysomy of chromosome 7 in the epithelial components. Immunohistochemically, in the stromal components, EGFR expression was demonstrable in four of 11 tumors and androgen receptor was demonstrated in six of 10 tumors. Neither Her-2/neu nor c-kit expression was seen in the stromal components of any of the 11 tumors. In the epithelial components, EGFR expression was present in all 11 tumors with strong staining in the basal cell layers and weak or no staining in luminal epithelium; androgen receptor expression was seen in seven of 10 tumors; Her-2/neu was weakly positive in four of 11 tumors; and c-kit expression was present focally and weakly in two of 11 cases with only 2-5% of cells staining. The highest staining intensity and the highest percentage of positively staining cells were seen with EGFR immunostaining in both the stromal and epithelial (mainly basal cells) components. Androgen receptor staining showed the next highest staining intensity and percentage of positive cells in both components. Her-2/neu and c-kit were only weakly or infrequently expressed in the epithelial components of prostatic phyllodes tumors. Our data indicate that EGFR and androgen receptor are frequently and strongly expressed in both epithelial and stromal components of prostatic phyllodes tumors. EGFR gene amplification is frequently present in prostatic phyllodes tumors and may account for one of the mechanisms leading to protein overexpression in some but not all cases. Anti-EGFR and/or antiandrogen agents may be potentially useful for management of patients with tumors expressing EGFR and/or androgen receptor.