Microvessel density in prostate cancer: lack of correlation with tumor grade, pathologic stage, and clinical outcome

Microvascular proliferation is associated with high tumour blood flow by mpMRI and disease progression in primary prostate cancer

Active angiogenesis may be assessed by immunohistochemistry using Nestin, a marker of newly formed vessels, combined with Ki67 for proliferating cells. Here, we studied microvascular proliferation by Nestin-Ki67 co-expression in prostate cancer, focusing on relations to quantitative imaging parameters from anatomically matched areas obtained by preoperative mpMRI, clinico-pathological features and prognosis. Tumour slides from 67 patients (radical prostatectomies) were stained for Nestin-Ki67. Proliferative microvessel density (pMVD) and presence of glomeruloid microvascular proliferation (GMP) were recorded. From mpMRI, forward volume transfer constant (Ktrans), reverse volume transfer constant (kep), volume of EES (ve), blood flow, and apparent diffusion coefficient (ADC) were obtained. High pMVD was associated with high blood flow (p = 0.008) and low ADC (p = 0.032). High Ktrans, kep, and blood flow were associated with high Gleason score. High pMVD, GMP, and low ADC were associated with most adverse clinico-pathological factors. Regarding prognosis, high pMVD, Ktrans, kep, and low ADC were associated with reduced biochemical recurrence-free- and metastasis-free survival (p ≤ 0.044) and high blood flow with reduced time to biochemical- and clinical recurrence (p < 0.026). In multivariate analyses however, microvascular proliferation was a stronger predictor compared with blood flow. Indirect, dynamic markers of angiogenesis from mpMRI and direct, static markers of angiogenesis from immunohistochemistry may aid in the stratification and therapy planning of prostate cancer patients.

Prostate Cancer Microvascular Routes: Exploration and Measurement Strategies

Angiogenesis is acknowledged as a pivotal feature in the pathology of human cancer. Despite the absence of universally accepted markers for gauging the comprehensive angiogenic activity in prostate cancer (PCa) that could steer the formulation of focused anti-angiogenic treatments, the scrutiny of diverse facets of tumoral blood vessel development may furnish significant understanding of angiogenic processes. Malignant neoplasms, encompassing PCa, deploy a myriad of strategies to secure an adequate blood supply. These modalities range from sprouting angiogenesis and vasculogenesis to intussusceptive angiogenesis, vascular co-option, the formation of mosaic vessels, vasculogenic mimicry, the conversion of cancer stem-like cells into tumor endothelial cells, and vascular pruning. Here we provide a thorough review of these angiogenic mechanisms as they relate to PCa, discuss their prospective relevance for predictive and prognostic evaluations, and outline the prevailing obstacles in quantitatively evaluating neovascularization via histopathological examinations.

Differential diagnosis of prostate cancer and benign prostatic hyperplasia based on DCE-MRI using bi-directional CLSTM deep learning and radiomics

Dynamic contrast-enhanced MRI (DCE-MRI) is routinely included in the prostate MRI protocol for a long time; its role has been questioned. It provides rich spatial and temporal information. However, the contained information cannot be fully extracted in radiologists' visual evaluation. More sophisticated computer algorithms are needed to extract the higher-order information. The purpose of this study was to apply a new deep learning algorithm, the bi-directional convolutional long short-term memory (CLSTM) network, and the radiomics analysis for differential diagnosis of PCa and benign prostatic hyperplasia (BPH). To systematically investigate the optimal amount of peritumoral tissue for improving diagnosis, a total of 9 ROIs were delineated by using 3 different methods. The results showed that bi-directional CLSTM with ± 20% region growing peritumoral ROI achieved the mean AUC of 0.89, better than the mean AUC of 0.84 by using the tumor alone without any peritumoral tissue (p = 0.25, not significant). For all 9 ROIs, deep learning had higher AUC than radiomics, but only reaching the significant difference for ± 20% region growing peritumoral ROI (0.89 vs. 0.79, p = 0.04). In conclusion, the kinetic information extracted from DCE-MRI using bi-directional CLSTM may provide helpful supplementary information for diagnosis of PCa.

Xenografts on nude mouse diaphragm of human DU145 prostate carcinoma cells: mesothelium removal by outgrowths and angiogenesis

Human prostate carcinoma DU145 cells, androgen-independent malignant cells, implanted in the athymic nu/nu male mouse, developed numerous tumors on peritoneal and retro-peritoneal organs whose growth aspects and vascular supply have yet to be investigated with fine structure techniques. A series of necropsies from moribund implanted mice diaphragms were examined with light, scanning, and transmission electron microscopy. DU145 xenografts installations, far away from the implanted site, were described as the smallest installation to large diaphragm outgrowths in moribund mice. Carcinomas did not show extracellular matrix and, reaching more than 0.15 mm in thickness, they revealed new structures in these outgrowths. Voids to be gland-like structures with mediocre secretion and, unexpectedly, intercellular spaces connected with fascicles of elongated DU145 cells that merged with a vascular supply originated from either the tumor cells and/or some perimysium vessels. In the largest carcinomas, most important vascular invasions coincidently accompanied the mouse lethality, similarly to human cancers. This androgen-independent model would be useful to study tumor outgrowth's changes related to testing anticancer strategy, including anti-angiogenic therapies involving toxicity, simultaneously with those of other vital organs with combined biomolecular and fine structure techniques.

The role of androgen receptors in vascular and cell proliferation of the prostate adenocarcinomas

Prostate adenocarcinoma (PA) is by incidence and prognosis a unique model for investigating the biomolecular mechanisms involved in tumor progression. In this study, we analyzed the immunoexpression of androgen receptor (AR), cluster of differentiation 105 (CD105) and Ki67 for 61 cases of PA, in relation to the main clinicopathological parameters of the lesions. The AR scores, CD105 microvessel density (MVD) and Ki67 proliferation index (PI) were significantly higher in patients with serum prostate-specific antigen (PSA) above 20 ng/mL, in ductal, colloid and sarcomatoid types of PA, in growth patterns 4–5 or mixed, respectively in the case of high-grade advanced stage tumors, with perineural and vascular invasion, as well as in groups with a reserved prognosis. The results obtained, reflected in the positive linear correlation of AR, CD105 and Ki67 expression, indicate synchronous endocrine, angiogenic and proliferative mechanisms involved in tumor progression, which can be used to optimize the targeted tumor therapy.

The potential of tumour microenvironment markers to stratify the risk of recurrence in prostate cancer patients

The tumour micro-environment (TME) plays a crucial role in the onset and progression of prostate cancer (PCa). Here we studied the potential of a selected panel of TME-markers to predict clinical recurrence (CLR) in PCa. Patient cohorts were matched for the presence or absence of CLR 5 years post-prostatectomy. Tissue micro-arrays (TMA) were composed with both prostate non-tumour (PNT) and PCa tissue and subsequently processed for immunohistochemistry (IHC). The IHC panel included markers for cancer activated fibroblasts (CAFs), blood vessels and steroid hormone receptors ((SHR): androgen receptor (AR), progesterone receptor (PR) and estrogen receptor (ER)). Stained slides were digitalised, selectively annotated and analysed for percentage of marker expression with standardized and validated image analysis algorithms. A univariable analysis identified several TME markers with significant impact on CR: expression of CD31 (vascular marker) in PNT stroma, expression of alpha smooth muscle actin (αSMA) in PCa stroma, and PR expression ratio between PCa stroma and PNT stroma. A multivariable model, which included CD31 expression (vascular marker) in PNT stroma and PR expression ratio between PCa stroma and PNT stroma, could significantly stratify patients for CLR, with the identification of a low risk and high-risk subgroup. If validated and confirmed in an independent prospective series, this subgroup might have clinical potential for PCa patient stratification.

Age-related and zonal anatomical microstructure features of normal prostatic tissues: a preliminary study with VERDICT MRI

PURPOSE

This study aimed to explore the differences in VERDICT parameters for normal prostatic tissues among different regions and age groups.

MATERIALS AND METHODS

In total, 31 male volunteers were included in the study. Vascular, extracellular and restricted diffusion for cytometry in tumors (VERDICT) model parameters (fIC, intracellular volume fraction; fEES, extracellular-extravascular space fraction; and fVASC, vascular fraction) were calculated based on the whole prostate volume and the peripheral zone (PZ), central gland (CG) and anterior fibromuscular stroma (AS) regions of interest (ROIs). Agreement between two readers was determined by calculating the intraclass correlation coefficient. Two-way ANOVA was used to identify significant differences among age groups and regions within the prostate. Age-related and area-related changes in these parameters were assessed using Spearman's correlation coefficients.

RESULTS

There were differences in the parameters among regions of the prostate (P < 0.05). In the PZ, there was a negative correlation between age and fIC (r = - 0.66, P < 0.001, adjusted P < 0.001), and age was positively correlated with fEES (r = 0.69, P < 0.001, adjusted P < 0.001) but had no correlation with fVASC. In the CG ROI, there was a positive correlation between age and fEES (r = 0.56, P < 0.001, adjusted P < 0.001) but no correlation between age and fVASC, similar to the results for the PZ. There were no correlations between age and VERDICT parameters in the AS.

CONCLUSION

VERDICT parameters vary among different regions of the prostate and correlate with age. These findings are in agreement with histological theory.

Diagnostic, prognostic and predictive parameters in prostate cancer

Prostate cancer (CP) is the most common malignancy in men in America, while it is the second most common in Europe. It is responsible for about 10% of cancer deaths in the same population. It is clinically manifested in various forms, from slow-growing to aggressive forms with pronounced metastatic potential. Diagnosis is made by a well-defined algorithm, which begins with the determination of serum prostate specific antigen values and ends with prostate biopsy as the "gold standard". Pathohistological diagnostic criterias are based on architectural, cytoplasmic, nuclear and characteristics of intraluminal structures, as well as periacinar cleftings, which are deffined as helpfull diagnostic criteria of undoubted importance. Prognostic and predictive parameters are classified into three categories. Some of them are an integral part of routine pathohistologicat report, while others are considered as the diagnostic process progresses. Modern knowledge introduces biomarkers into the everyday practice of personalized medicine, especially when is necessary to treat prostate cancer patients.

Hypoxia and angiogenic biomarkers in prostate cancer after external beam radiotherapy (EBRT) alone or combined with high-dose-rate brachytherapy boost (HDR-BTb)

PURPOSE

To investigate angiogenic and hypoxia biomarkers to predict outcome in patients receiving external beam radiotherapy (EBRT) alone or combined with high-dose-rate brachytherapy boost (HDR-BTb) for localised prostate cancer.

METHODS

Prostate biopsy samples were collected prospectively in patients entered into a phase 3 randomised controlled trial of patients receiving EBRT or EBRT + HDR-BTb. Univariate and multivariate analyses using Cox proportional hazards model were performed to identify associations between immunohistochemical staining of hypoxia inducible factor 1 alpha (HIF1α), glucose transporter 1 (GLUT1), osteopontin (OPN) and microvessel density (MVD) using CD-34 antibody with clinical outcome. The primary endpoint was biochemical relapse free survival (BRFS) and secondary endpoint was distant metastasis free survival (DMFS).

RESULTS

Immunohistochemistry was available for 204 patients. Increased OPN (Hazard ratio [HR] 2.38, 95% Confidence Interval [CI] 1.06-5.34, p < 0.036) and GLUT1 (HR 2.36, 95%CI 1.39-4.01, p < 0.001) expression were predictive of worse BRFS. Increased GLUT1 expression (HR 2.22, 1.02-4.84, p = 0.045) was predictive of worse DMFS. Increased MVD (CD-34) (HR 1.82, 95%CI 1.06-3.14, p = 0.03) and OPN (HR 1.82, 95%CI 1.06-3.14, p = 0.03) but reduced GLUT1 expression (HR 0.40, 95%CI 0.20-0.79, p = 0.009) were predictive of improved BRFS in patients receiving EBRT + HDR-BTb.

CONCLUSION

Our data suggest angiogenic and hypoxia biomarkers may predict outcome and benefit of dose escalation, however further validation in prospective studies including hypoxia modification is needed. Trial registration number ISRCTN98241100, registered with ISRCTN at http://www.controlled-trials.com/isrctn/.

Photoacoustic tomography for imaging the prostate: a transurethral illumination probe design and application

In vivo imaging of prostate cancer with photoacoustic tomography is currently limited by the lack of sufficient local fluence for deep tissue penetration and the risk of over-irradiation near the laser-tissue contact surface. We propose the design of a transurethral illumination probe that addresses those limitations. A high energy of 50 mJ/pulse is coupled into a 1000-µm-core diameter multimode fiber. A 2 cm diffusing end is fabricated, which delivers light in radial illumination. The radial illumination is then reflected and reshaped by a parabolic cylindrical mirror to obtain nearly parallel side illumination with a doubled fluence. The fiber assembly is housed in a 25 Fr cystoscope sheath to provide protection of the fiber and maintain a minimal laser-tissue contact distance of 5 mm. A large laser-tissue contact surface area of 4 cm² is obtained and the fluence on the tissue surface is kept below the maximum permissible exposure. By imaging a prostate mimicking phantom, a penetration depth of 3.5 cm at 10 mJ/cm² fluence and 700 nm wavelength is demonstrated. The results indicate that photoacoustic tomography with the proposed transurethral probe has the potential to image the entire prostate while satisfying the fluence maximum permissible exposure and delivering a high power to the tissue.

VERDICT-AMICO: Ultrafast fitting algorithm for non-invasive prostate microstructure characterization

VERDICT (vascular, extracellular and restricted diffusion for cytometry in tumours) estimates and maps microstructural features of cancerous tissue non-invasively using diffusion MRI. The main purpose of this study is to address the high computational time of microstructural model fitting for prostate diagnosis, while retaining utility in terms of tumour conspicuity and repeatability. In this work, we adapt the accelerated microstructure imaging via convex optimization (AMICO) framework to linearize the estimation of VERDICT parameters for the prostate gland. We compare the original non-linear fitting of VERDICT with the linear fitting, quantifying accuracy with synthetic data, and computational time and reliability (performance and precision) in eight patients. We also assess the repeatability (scan-rescan) of the parameters. Comparison of the original VERDICT fitting versus VERDICT-AMICO showed that the linearized fitting (1) is more accurate in simulation for a signal-to-noise ratio of 20 dB; (2) reduces the processing time by three orders of magnitude, from 6.55 seconds/voxel to 1.78 milliseconds/voxel; (3) estimates parameters more precisely; (4) produces similar parametric maps and (5) produces similar estimated parameters with a high Pearson correlation between implementations, r2  > 0.7. The VERDICT-AMICO estimates also show high levels of repeatability. Finally, we demonstrate that VERDICT-AMICO can estimate an extra diffusivity parameter without losing tumour conspicuity and retains the fitting advantages. VERDICT-AMICO provides microstructural maps for prostate cancer characterization in seconds.

Convective-Dispersion Modeling in 3D Contrast-Ultrasound Imaging for the Localization of Prostate Cancer

Despite being the solid tumor with the highest incidence in western men, prostate cancer (PCa) still lacks reliable imaging solutions that can overcome the need for systematic biopsies. Dynamic contrast-enhanced ultrasound imaging (DCE-US) allows us to quantitatively characterize the vascular bed in the prostate, due to its ability to visualize an intravenously administered bolus of contrast agents. Previous research has demonstrated that DCE-US parameters related to the vascular architecture are useful markers for the localization of PCa lesions. In this paper, we propose a novel method to assess the convective dispersion (D) and velocity (v) of the contrast bolus spreading through the prostate from three-dimensional (3D) DCE-US recordings. By assuming that D and v are locally constant, we solve the convective-dispersion equation by minimizing the corresponding regularized least-squares problem. 3D multiparametric maps of D and v were compared with 3D histopathology retrieved from the radical prostatectomy specimens of six patients. With a pixel-wise area under the receiver operating characteristic curve of 0.72 and 0.80, respectively, the method shows diagnostic value for the localization of PCa.

Prostate cancer aggressiveness and age: Impact of p53, BCL-2 and microvessel density

Older men are more likely to have advanced prostate cancer at time of their diagnosis, but whether prostate tumors are inherently (biologically) more aggressive with advancing age is uncertain. To address this gap in knowledge, we analyzed data from veterans (n=971) diagnosed with prostate cancer during 1991–1995. Factors included age, detection of prostate cancer by screening, prostate-specific antigen (PSA) level, anatomic stage, and Gleason score. Information on molecular markers obtained from immunohistochemical staining of prostate tissue, included B cell lymphoma-2 (bcl-2), p53, and microvessel density (MVD), each having a previously documented association with disease progression and increased risk of prostate cancer death. We first examined the bivariate association of demographic, clinical, and molecular factors with age, and found evidence that race, screening status, Gleason score, PSA, bcl-2, p53, and MVD varied across categories of age in this study population. After further characterizing the association between age and Gleason score, we used logistic regression to examine the association between age and molecular markers—accounting for race, screening status, PSA, and Gleason score. Comparing men older than 80 years to those younger than 70 years, adjusted ORs and 95% CIs were 1.89 (0.73 to 4.92), 1.91 (1.05 to 3.46), and 2.00 (1.06 to 3.78), for positive bcl-2, p53, and MVD markers, respectively; no statistically significant associations were found for men 70–79 years old, compared with men younger than 70 years. These novel findings suggest that very elderly men often present with biologically aggressive prostate cancer; the results also have potential implications for therapeutic decision-making.

Cellular Constituents of the Prostate Stroma: Key Contributors to Prostate Cancer Progression and Therapy Resistance

Reciprocal signaling between prostate stroma and its epithelium are fundamental to organ development and homeostasis. Similarly, interactions between tumor cells and stromal constituents are central to key aspects of carcinogenesis and malignancy growth involving tumor cell invasion, dissemination, and growth in distant sites. The prostate stroma is complex with several distinct resident cell types, infiltrating nonresident cell types and an amalgam of structural matrix factors, matricellular proteins, metabolites, growth factors, and cytokines. Of importance, the stroma is dynamic with changes in composition as a cause or consequence of intrinsic and extrinsic factors. In the context of epithelial neoplasia, the prostate stroma undergoes phenotypic changes with a loss of well-differentiated smooth muscle cell population and the expansion of cancer-associated fibroblast populations. This reactive stroma further coevolves with tumor progression. Recent studies show the role of tumor microenvironment components in therapy resistance and highlight the importance of a thorough knowledge of cross talk between tumor cells and microenvironment niches to develop new therapeutic strategies.

The Value of Contrast-Enhanced Ultrasonography Combined with Real-Time Strain Elastography in the Early Diagnosis of Prostate Cancer

To evaluate the performance of a combination of real-time strain elastography (RTSE) and contrast-enhanced transrectal ultrasound (CETRUS) for prostate cancer detection. Patients with serum prostate-specific antigen (PSA) levels of ≥4.0 ng/ml were prospectively enrolled between June 2014 and December 2016. 153 prostate nodules diagnosed by conventional ultrasound were prospectively enrolled and examined by CETRUS and RTSE before a biopsy. Multivariate logistic regression models were established for CETRUS, and CETRUS combined with RTSE to diagnose prostate malignancy. The diagnostic performances of CETRUS, RTSE, and their combined use were evaluated with the receiver operating characteristic (ROC) curve. The multivariate logistic regression for CETRUS combined with RTSE showed that enhanced strength, enhanced uniformity, and elasticity scores were the independent predictors of prostate malignancy. The area under the ROC curve of CETRUS combined with RTSE (0.921±0.023) was higher than that of CETRUS and RTSE (0.88±0.029 and 0.80±0.038, respectively; both p<0.05). Moreover, the sensitivity, accuracy and negative predictive value of CETRUS combined with RTSE were 92.1%, 86.2%, and 84.6%, respectively. The omission diagnostic rate of CETRUS combined with RTSE (7.9%) was reduced. And the diagnostic accuracy of CETRUS combined with RTSE was significantly higher than that of CETRUS and RTSE (p<0.05). While the diagnostic accuracy of CETRUS was close to the RTSE, the difference was not statistically significant (p>0.05). The combined RTSE with CETRUS approach significantly improved the sensitivity and overall accuracy for correctly identifying prostate cancer.

The importance of microvessel density in predicting cancer progression in patients with penile squamous cell carcinoma

PURPOSE

To evaluate the role of microvessel density (MVD) in predicting lymph node (LN) metastasis in penile squamous cell carcinoma (PSCC).

MATERIALS AND METHODS

Records of 266 patients with PSCC were analyzed. Parameters examined were tumor stage, grade, nodal status, intratumoral and peritumoral MVD. Univariate and multivariate analyses were used to evaluate association between different histopathological variables and MVD. ROC was plotted to derive a prediction model using appropriate cutoff values of the parameters predicting cancer progression.

RESULTS

77 patients were found to have histologically proven metastatic LN. MVD did not correlate significantly with T stage and grade of tumor. The intratumoral and peritumoral MVD of patients with metastatic LN was significantly higher than patients with negative LN (58.92 vs. 49.89 and 65.57 vs. 53.72, respectively; P < 0.0001). Multivariate analysis also revealed that MVD (intratumoral and peritumoral) was independent predictor for LN metastasis. From ROC curve, at the cutoff value of 54, intratumoral MVD predicted LN metastasis with sensitivity of 91% and specificity of 87%. Similarly, at cutoff value of 61, peritumoral MVD predicted LN metastasis with sensitivity of 94% and specificity of 89%. The 5-year survival was 79 and 77% for those with low intratumoral and peritumoral MVD, respectively, as compared to 41 and 39% for those with high intratumoral and peritumoral MVD, respectively (P < 0.05).

CONCLUSIONS

Higher intratumoral and peritumoral MVD predicts cancer progression in patients with PSCC. Patients with an intratumoral MVD of 54 and peritumoral MVD of 61 have lymph node metastasis with a high sensitivity and specificity. The overall 5-year survival of patients is poor in high intratumoral or peritumoral MVD.

Dynamic contrast-enhanced MRI for oncology drug development

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is a promising tool for evaluating tumor vascularity, as it can provide vasculature-derived, functional, and quantitative parameters. To implement DCE-MRI parameters as biomarkers for monitoring the effect of antiangiogenic or vascular-disrupting treatment, two crucial elements of surrogate endpoint, ie, validation and qualification, should be satisfied. Although early studies have shown the accuracy and reliability of DCE-MRI parameters for evaluating treatment-driven vascular alterations, there have been an increasing number of studies demonstrating the limitations of DCE-MRI parameters as surrogate endpoints. Therefore, in order to improve the application of DCE-MRI parameters in drug development, it is necessary to establish a standardized evaluation method and to determine the correct therapeutics-oriented meaning of individual DCE-MRI parameter. In this regard, this article describes the biophysical background and data acquisition/analysis techniques of DCE-MRI while focusing on the validation and qualification issues. Specifically, the causes of disagreement and confusion encountered in the preclinical and clinical trials using DCE-MRI are presented in detail. Finally, considering these limitations, we present potential strategies to optimize implementation of DCE-MRI. J. Magn. Reson. Imaging 2016;44:251-264.

Hypoxia imaging in gliomas with 18F-fluoromisonidazole PET: toward clinical translation

There is significant interest in the development of improved image-guided therapy for neuro-oncology applications. Glioblastomas (GBM) in particular present a considerable challenge because of their pervasive nature, propensity for recurrence, and resistance to conventional therapies. MRI is routinely used as a guide for planning treatment strategies. However, this imaging modality is not able to provide images that clearly delineate tumor boundaries and affords only indirect information about key tumor pathophysiology. With the emergence of PET imaging with new oncology radiotracers, mapping of tumor infiltration and other important molecular events such as hypoxia is now feasible within the clinical setting. In particular, the importance of imaging hypoxia levels within the tumoral microenvironment is gathering interest, as hypoxia is known to play a central role in glioma pathogenesis and resistance to treatment. One of the hypoxia radiotracers known for its clinical utility is (18)F-fluoromisodazole ((18)F-FMISO). In this review, we highlight the typical causes of treatment failure in gliomas that may be linked to hypoxia and outline current methods for the detection of hypoxia. We also provide an overview of the growing body of studies focusing on the clinical translation of (18)F-FMISO PET imaging, strengthening the argument for the use of (18)F-FMISO hypoxia imaging to help optimize and guide treatment strategies for patients with glioblastoma.

Prolactin- and testosterone-induced carboxypeptidase-D correlates with increased nitrotyrosines and Ki67 in prostate cancer

BACKGROUND

Carboxypeptidase-D (CPD) cleaves C-terminal arginine for conversion to nitric oxide (NO) by nitric oxide synthase (NOS). Prolactin (PRL) and androgens stimulate CPD gene transcription and expression, which increases intracellular production of NO to promote viability of prostate cancer (PCa) cells in vitro. The current study evaluated whether hormonal upregulation of CPD and NO promote PCa cell viabilty in vivo, by correlating changes in expression of CPD and nitrotyrosine residues (products of NO action) with proliferation marker Ki67 and associated proteins during PCa development and progression.

METHODS

Fresh prostate tissues, obtained from 40 men with benign prostatic hyperplasia (BPH) or PCa, were flash-frozen at the time of surgery and used for RT-qPCR analysis of CPD, androgen receptor (AR), PRL receptor (PRLR), eNOS, and Ki67 levels. Archival paraffin-embedded tissues from 113 men with BPH or PCa were used for immunohistochemical (IHC) analysis of CPD, nitrotyrosines, phospho-Stat5 (for activated PRLR), AR, eNOS/iNOS, and Ki67.

RESULTS

RT-qPCR and IHC analyses showed strong AR and PRLR expression in benign and malignant prostates. CPD mRNA levels increased ∼threefold in PCa compared to BPH, which corresponded to a twofold increase in Ki67 mRNA levels. IHC analysis showed a progressive increase in CPD from 11.4 ± 2.1% in benign to 21.8 ± 3.2% in low-grade (P = 0.007), 40.7 ± 4.0% in high-grade (P < 0.0001) and 50.0 ± 9.5% in castration-recurrent PCa (P < 0.0001). Immunostaining for nitrotyrosines and Ki67 mirrored these increases during PCa progression. CPD, nitrotyrosines, and Ki67 tended to co-localize, as did phospho-Stat5.

CONCLUSIONS

CPD, nitrotyrosine, and Ki67 levels were higher in PCa than in benign and tended to co-localize, along with phospho-Stat5. The strong correlation in expression of these proteins in benign and malignant prostate tissues, combined with abundant AR and PRLR, supports in vitro evidence that the CPD-Arg-NO pathway is involved in the regulation of PCa cell proliferation. It further highlights a role for PRL in the development and progression of PCa.

Association between tumor-associated macrophages and microvessel density on prostate cancer progression

Background

To evaluate tumor-associated macrophages (TAMs) infiltration and microvessel density as possible prognostic factors related to prostate cancer (PCa) progression.

Methods

Immunostaining of TAMs in prostate biopsy specimens was performed using a monoclonal antibody CD68 and microvessel density (MVD) using von Willebrand factor (vWF) from 25 specimens with high-grade prostatic intraepithelial neoplasia (HGPIN) and 25 specimens with PCa after transurethral resection of the prostate (TURP). Six microscopic (×200) fields were selected for TAM counting and six microscopic (×100) fields were selected for MVD counting around the cancer foci. Association between age, preoperative prostate-specific antigen (PSA), pathologic Gleason sum (GS), TAM, MVD, extracapsular extension, and metastasis were assessed using Pearson/Spearman, Student t test/Mann-Whitney U test and one-way analysis of variance/Kruskal-Wallis test.

Results

The mean of age, PSA, TAMs, and MVD were 69.1 ± 9.9, 67.1 ± 92.4, 26.2 ± 11.9, and 31.4 ± 14.0, respectively, from 50 specimens with PCa and HGPIN. Increasing TAMs number was not correlated with increasing MVD number and there was no significant mean difference statistically (P > 0.05) in TAMs and MVD although the mean of TAMs number was higher in PCa versus HGPIN but significant in PSA level (P < 0.001). In PCa specimens, age, PSA, TAMs, and MVD number were higher in patients with metastatic and extracapsular extension, but not significant statistically (P > 0.005). There was no correlation between TAMs and MVD (P > 0.001).

Conclusions

TAMs and MVD had increased PCa but did not provide independent prognostic value. Increasing numbers of TAMs was not always followed by an increase in MVD. HGPIN is the most likely precursor for PCa.

Reconsideration of the clinical and histopathological significance of angiogenesis in prostate cancer: Usefulness and limitations of microvessel density measurement

Angiogenesis plays important roles in tumor growth and cancer cell dissemination in almost all cancers. In prostate cancer, there is general agreement that increased angiogenesis is an important factor in determining tumor development and prognosis in these patients. Microvessel density is recognized as a useful marker for evaluating the angiogenic status of cancer tissues. Many investigators have reported that microvessel density is significantly associated with pathological features and outcomes in prostate cancer patients; however, some researchers have expressed opposing opinions. As the reason for such discrepancy, previous reports have suggested differences in the methodologies of measuring microvessel density in cancer tissues. In the present review, we focus on the variation in such methods, including the selected area and the method used for (semi)quantification. In particular, we discuss the relationship between malignancy potential, tumor progression, and survival and differences in the antibodies used for detection of endothelial cells in detail. We briefly compare the pathological significance and prognostic roles of microvessel density measured using von Willebrand factor, CD31, CD34, and CD105. Based on these analyses, the advantages and limitations of microvessel density measurements in prostate cancer tissues are clarified. Improved "real" and "specific" markers of cancer-related angiogenesis are necessary for better predictions of prognoses and for discussion of treatment strategies for patients with prostate cancer. However, establishment of a satisfactory cancer-related endothelial marker could take a long time. Therefore, knowledge regarding the pathological significance of microvessel density - based on understanding of the advantages and limitations of microvessel density determination methods - is important.

Contrast enhanced computed tomography is indicative for angiogenesis pattern and display prognostic significance in breast cancer

Background

The Prognostic value of microvessel density in cancer remains unclear. Recent studies have suggested that the uneven distribution of microvessels in tumours caused the variation in sample selection which led to different prognostic outcome. The enhancement pattern of Contrast-enhanced computed tomography (CECT) is determined in part by the microvessel distribution in solid tumors. Therefore, survival analysis of tumors grouping by the enhancement pattern and the pattern of microvessel distribution is important.

Methods

Survival analysis grouped by the tumor enhancement pattern and the microvessel distribution was carried out in 255 patients with invasive ductal carcinoma.

Results

There were significant differences in overall survival (OS) and disease-free survival (DFS) among the homogeneous, heterogeneous and peripheral enhancement groups. There were significant differences between OS and DFS groups with uniform and uneven distributions of microvessels.

Conclusions

The distribution of microvessels in a tumor is a potential prognostic indicator in patients with breast cancer, and can be assessed by CECT prior the operation.

Assessment of prostate cancer aggressiveness using dynamic contrast-enhanced magnetic resonance imaging at 3 T

BACKGROUND

A challenge in the diagnosis of prostate cancer (PCa) is the accurate assessment of aggressiveness.

OBJECTIVE

To validate the performance of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) of the prostate at 3 tesla (T) for the assessment of PCa aggressiveness, with prostatectomy specimens as the reference standard.

DESIGN, SETTINGS, AND PARTICIPANTS

A total of 45 patients with PCa scheduled for prostatectomy were included. This study was approved by the institutional review board; the need for informed consent was waived.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Subjects underwent a clinical MRI protocol including DCE-MRI. Blinded to DCE-images, PCa was indicated on T2-weighted images based on histopathology results from prostatectomy specimens with the use of anatomical landmarks for the precise localization of the tumor. PCa was classified as low-, intermediate-, or high-grade, according to Gleason score. DCE-images were used as an overlay on T2-weighted images; mean and quartile values from semi-quantitative and pharmacokinetic model parameters were extracted per tumor region. Statistical analysis included Spearman's ρ, the Kruskal-Wallis test, and a receiver operating characteristics (ROC) analysis.

RESULTS AND LIMITATIONS

Significant differences were seen for the mean and 75th percentile (p75) values of wash-in (p = 0.024 and p = 0.017, respectively), mean wash-out (p = 0.044), and p75 of transfer constant (K(trans)) (p = 0.035), all between low-grade and high-grade PCa in the peripheral zone. ROC analysis revealed the best discriminating performance between low-grade versus intermediate-grade plus high-grade PCa in the peripheral zone for p75 of wash-in, K(trans), and rate constant (Kep) (area under the curve: 0.72). Due to a limited number of tumors in the transition zone, a definitive conclusion for this region of the prostate could not be drawn.

CONCLUSIONS

Quantitative parameters (K(trans) and Kep) and semi-quantitative parameters (wash-in and wash-out) derived from DCE-MRI at 3 T have the potential to assess the aggressiveness of PCa in the peripheral zone. P75 of wash-in, K(trans), and Kep offer the best possibility to discriminate low-grade from intermediate-grade plus high-grade PCa.

Differential expression of VEGF ligands and receptors in prostate cancer

BACKGROUND

Prostate cancer disseminates to regional lymph nodes, however the molecular mechanisms responsible for lymph node metastasis are poorly understood. The vascular endothelial growth factor (VEGF) ligand and receptor family have been implicated in the growth and spread of prostate cancer via activation of the blood vasculature and lymphatic systems. The purpose of this study was to comprehensively examine the expression pattern of VEGF ligands and receptors in the glandular epithelium, stroma, lymphatic vasculature and blood vessels in prostate cancer.

METHODS

The localization of VEGF-A, VEGF-C, VEGF-D, VEGF receptor (VEGFR)-1, VEGFR-2, and VEGFR-3 was examined in cancerous and adjacent benign prostate tissue from 52 subjects representing various grades of prostate cancer.

RESULTS

Except for VEGFR-2, extensive staining was observed for all ligands and receptors in the prostate specimens. In epithelial cells, VEGF-A and VEGFR-1 expression was higher in tumor tissue compared to benign tissue. VEGF-D and VEGFR-3 expression was significantly higher in benign tissue compared to tumor in the stroma and the endothelium of lymphatic and blood vessels. In addition, the frequency of lymphatic vessels, but not blood vessels, was lower in tumor tissue compared with benign tissue.

CONCLUSIONS

These results suggest that activation of VEGFR-1 by VEGF-A within the carcinoma, and activation of lymphatic endothelial cell VEGFR-3 by VEGF-D within the adjacent benign stroma may be important signaling mechanisms involved in the progression and subsequent metastatic spread of prostate cancer. Thus inhibition of these pathways may contribute to therapeutic strategies for the management of prostate cancer.

The prognostic significance of vasohibin-1 expression in patients with prostate cancer

Background:

We recently isolated vasohibin-1 (VASH1), a novel angiogenic molecule that is specifically expressed in activated vascular endothelial cells (ECs), and the status of VASH1 expression has been documented in various cancer angiogenesis. The aim of this study was to assess the prognostic value of VASH1 expression in prostate cancer (PCa).

Methods:

In this study, we retrospectively analysed the clinical records and evaluated the VASH1 expression of tumour microvessels in 167 patients with PCa who underwent radical prostatectomy. We immunohistochemically examined the microvessels positive for anti-CD34 as microvessel density (MVD) and the microvessels with activated ECs positive for VASH1 density.

Results:

We found that the VASH1 expression was restricted to ECs in the tumour stroma. VASH1 density was significantly associated with pathological T stage, Gleason score and MVD. The 5-year PSA recurrence-free survival rate was 58.8% in patients with higher VASH1 density (≧12 per mm²) and 89.1% in patients with lower VASH1 density (<12 per mm²), respectively (P<0.001). Microvessel density was not an independent predictor of PSA recurrence. Multivariate analysis revealed that high VASH1 density was an independent prognostic indicator of PSA recurrence (P=0.007, HR=2.950).

Conclusion:

VASH1 density represents a clinically relevant predictor of patient prognosis and can be a new biomarker that would provide additional prognostic information in PCa.

Nestin: A novel angiogenesis marker and possible target for tumor angiogenesis

Abnormal vasculature, termed tumor vessels, is a hallmark of solid tumors. The degree of angiogenesis is associated with tumor aggressiveness and clinical outcome. Therefore, exact quantification of tumor vessels is useful to evaluate prognosis. Furthermore, selective detection of newly formed tumor vessels within cancer tissues using specific markers raises the possibility of molecular targeted therapy via the inhibition of tumor angiogenesis. Nestin, an intermediate filament protein, is reportedly expressed in repair processes, various neoplasms, and proliferating vascular endothelial cells. Nestin expression is detected in endothelial cells of embryonic capillaries, capillaries of the corpus luteum, which replenishes itself by angiogenesis, and proliferating endothelial progenitor cells, but not in mature endothelial cells. Therefore, expression of nestin is relatively limited to proliferating vascular endothelial cells and endothelial progenitor cells. Nestin expression is also reported in blood vessels within glioblastoma, prostate cancer, colorectal cancer, and pancreatic cancer, and its expression is more specific for newly formed blood vessels than other endothelial cell markers. Nestin-positive blood vessels form smaller vessels with high proliferation activity in tumors. Knockdown of nestin in vascular endothelial cells suppresses endothelial cell growth and tumor formation ability of pancreatic cancers in vivo. Using nestin to more accurately evaluate microvessel density in cancer specimens may be a novel prognostic indicator. Furthermore, nestin-targeted therapy may suppress tumor proliferation via inhibition of angiogenesis in numerous malignancies, including pancreatic cancer. In this review article, we focus on nestin as a novel angiogenesis marker and possible therapeutic target via inhibition of tumor angiogenesis.

Tumour epithelial expression levels of endocannabinoid markers modulate the value of endoglin-positive vascular density as a prognostic marker in prostate cancer

Fatty acid amide hydrolase (FAAH) is responsible for the hydrolysis of the endogenous cannabinoid (CB) receptor ligand anandamide. Here we have investigated whether the expression levels of FAAH and CB1 receptors influence the prognostic value of markers of angiogenesis in prostate cancer. Data from a cohort of 419 patients who were diagnosed with prostate cancer at transurethral resection for lower urinary tract symptoms, of whom approximately 2/3 had been followed by expectancy, were used. Scores for the angiogenesis markers endoglin and von Willebrand factor (vWf), the endocannabinoid markers fatty acid amide hydrolase (FAAH) and cannabinoid CB1 receptors and the cell proliferation marker Ki-67 were available in the database. For the cases followed by expectancy, the prognostic value of endoglin was dependent upon the tumour epithelial FAAH immunoreactivity (FAAH-IR) and CB1IR scores, and the non-malignant epithelial FAAH-IR scores, but not the non-malignant CB1IR scores or the tumour blood vessel FAAH-IR scores. This dependency upon the tumour epithelial FAAH-IR or CB1IR scores was less apparent for vWf, and was not seen for Ki-67. Using an endoglin cut-off value of 10 positively stained vessels per core and a median split of tumour FAAH-IR, four groups could be generated, with 15year of disease-specific survival (%) of 68±7 (low endoglin, low FAAH), 45±11 (high endoglin, low FAAH), 77±6 (low endoglin, high FAAH) and 21±10 (high endoglin, high FAAH). Thus, the cases with high endoglin and high FAAH scores have the poorest rate of disease-specific survival. At diagnosis, the number of cases with tumour stages 1a-1b relative to stages 2-4 was sensitive to the endoglin score in a manner dependent upon the tumour FAAH-IR. It is concluded that the prognostic value of endoglin as a marker of neovascularisation in prostate cancer can be influenced by the expression level of markers of the endocannabinoid system. This article is part of a Special Issue entitled Lipid Metabolism in Cancer.

The role of treatment modality on the utility of predictive tissue biomarkers in clinical prostate cancer: a systematic review

BACKGROUND

Tissue biomarkers could pivotally improve clinical outcome prediction following prostate cancer therapy. Clinically, prostate cancer is managed by diverse treatment modalities whose individual influence on a biomarker's predictive ability is not well understood and poorly investigated in the literature.

OBJECTIVE

We conducted a systematic review to assess the predictive value of biomarkers in different treatment contexts in prostate cancer.

STUDY METHODOLOGY

A literature search was performed using the MeSH headings "prostate neoplasms" and "biological markers". Rigorous selection criteria identified studies correlating expression with clinical outcomes from primary androgen deprivation therapy (ADT), radical prostatectomy and radiotherapy (± neoadjuvant ADT).

STUDY RESULTS

Of 10,668 studies identified, 481 papers matched initial inclusion criteria. Following rescreening, 384 studies identified 236 individual tissue biomarkers, of which 29 were predictive on multivariate analysis in at least 2 independent cohorts. The majority were only tested in surgical cohorts. Only 8 predictive biomarkers were tested across all 3 treatments with Ki67 identified as universal predictive marker. p16 showed potential for treatment stratification between surgery and radiotherapy but needs further validation in independent studies.

CONCLUSIONS

Despite years of research, very few tissue biomarkers retain predictive value in independent validation across therapy context. Currently, none have conclusive ability to help treatment selection. Future biomarker research should consider the therapy context and use uniform methodology and evaluation criteria.

Microvessel density is not increased in prostate cancer: digital imaging of routine sections and tissue microarrays

Angiogenesis is considered a prognostic factor and therapy target in many tumors but remains controversial in prostate cancer. This study compares the microvessel density of normal prostate and prostate cancer of different grades using an automated approach to determine its clinical utility. Neoplastic and normal prostatic tissues from 60 prostatectomies were examined by routine histological sections (group I); 136 prostatectomies were used to create tissue microarrays (group II). Microvessel density was calculated using CD31 immunostaining. Automated Cellular Image System (ChromaVision, San Juan Capistrano, CA) and Aperio automated systems were used to digitally analyze microvessel density in Groups I and II respectively. Microvessel density was not significantly increased in tumor versus normal prostate in Group I (P = .303). Both the mean vessel count and vessel area were significantly higher in normal tissue than in tumor either by Automated Cellular Image System or Aperio analysis (P < .05). Aperio analysis in group II additionally showed significantly higher values in normal tissue for vessel lumen (P < .001), whereas vessel perimeter, wall thickness, vessel compactness, and shape were not significantly different (P > .05). Aperio comparison of low- versus high-grade prostate cancer demonstrated that only mean vessel count was increased in high-grade tumors (P = .047); no other automated parameter in either group showed significant association with Gleason scores. Irrespective of methodology, microvessel density was not increased in prostate cancer compared to normal prostate. The bias of using vascular hot spots that possibly contributed to previous contradictory results has been mitigated by automated microvessel density quantitation here. Similar microvessel density of low- and high-grade tumors indicate that microvessel density is neither an important nor reliable prognostic marker for prostate cancer.

Diffusion-weighted and dynamic contrast-enhanced MRI of prostate cancer: correlation of quantitative MR parameters with Gleason score and tumor angiogenesis

OBJECTIVE

The objective of our study was to investigate whether quantitative parameters derived from diffusion-weighted imaging (DWI) and dynamic contrast-enhanced MRI (DCE-MRI) correlate with Gleason score and angiogenesis of prostate cancer.

MATERIALS AND METHODS

Seventy-three patients who underwent preoperative MRI and radical prostatectomy were included in our study. A radiologist and pathologist located the dominant tumor on the MR images based on histopathologic correlation. For each dominant tumor, the apparent diffusion coefficient (ADC) value and quantitative DCE-MRI parameters (i.e., contrast agent transfer rate between blood and tissue [K(trans)], extravascular extracellular fractional volume [v(e)], contrast agent backflux rate constant [k(ep)], and blood plasma fractional volume on a voxel-by-voxel basis [v(p)]) were calculated and the Gleason score was recorded. The mean blood vessel count, mean vessel area fraction, and vascular endothelial growth factor (VEGF) expression of the dominant tumor were determined using CD31, CD34, and VEGF antibody stains. Spearman correlation analysis between MR and histopathologic parameters was conducted.

RESULTS

The mean tumor diameter was 15.2 mm (range, 5-28 mm). Of the 73 prostate cancer tumors, five (6.8%) had a Gleason score of 6, 46 (63%) had a Gleason score of 7, and 22 (30.1%) had a Gleason score of greater than 7. ADC values showed a moderate negative correlation with Gleason score (r = -0.376, p = 0.001) but did not correlate with tumor angiogenesis parameters. Quantitative DCE-MRI parameters did not show a significant correlation with Gleason score or VEGF expression (p > 0.05). Mean blood vessel count and mean vessel area fraction parameters estimated from prostate cancer positively correlated with k(ep) (r = 0.440 and 0.453, respectively; p = 0.001 for both).

CONCLUSION

There is a moderate correlation between ADC values and Gleason score and between k(ep) and microvessel density of prostate cancer. Although the strength of the correlations is insufficient for immediate diagnostic utility, these results warrant further investigation on the potential of multiparametric MRI to facilitate noninvasive assessment of prostate cancer aggressiveness and angiogenesis.

Angiogenesis and host immune response contribute to the aggressive character of non-melanoma skin cancers in renal transplant recipients

AIMS

The aim of this study was to determine the contribution of tumour angiogenesis to the aggressive growth of non-melanoma skin cancers (NMSCs) in renal transplant recipients (RTRs).

METHODS AND RESULTS

The study cohort included RTRs (n = 38) with formalin-fixed paraffin-embedded tumour samples available from first post-transplant NMSC (NMSC1) surgically excised at Christchurch Hospital, New Zealand, from 1997 to 2007. Comparable samples excised from immunocompetent individuals (ICIs) (n = 36) were selected to accommodate confounding factors. Markers of tumour angiogenesis were evaluated by immunohistochemistry, and analysed for associations with clinicopathological variables. As compared with ICIs, RTRs had a higher proportion of tumours with high microvessel density (P = 0.008), high proliferating capillary index (P < 0.0001) and low microvessel pericyte coverage index (P < 0.0001), and RTRs had a shorter cumulative second NMSC (NMSC2)-free interval (P < 0.0001). ICIs had a higher proportion of tumours with a 'marked' number of vascular endothelial growth factor (VEGF)-A-positive leukocytes than RTRs (P = 0.04), and RTRs with a 'moderate/marked' number of VEGF-A-positive leukocytes had longer cumulative NMSC2-free intervals than those with a 'minimum' number (P = 0.02).

CONCLUSIONS

This study demonstrates increased tumour angiogenesis in NMSC in RTRs, and suggests a role for VEGF-A-positive peritumoural leukocytes in suppressing NMSC development.

Vascular proliferation is a prognostic factor in breast cancer

Angiogenesis is important for the growth and spread of malignant tumors, and anti-angiogenesis treatment is currently being evaluated for breast cancer and other tumors. Although microvessel density is the most commonly used tissue-based marker of tumor associated angiogenesis, it has significant limitations and has not proven effective as a predictive factor in selecting patients for treatment. We here wanted to explore the significance of vascular endothelial cell proliferation in breast carcinoma. We examined microvessel proliferation in breast cancer by dual immunohistochemical staining, using the pan-endothelial marker Factor-VIII combined with proliferation of endothelial cells by Ki-67 expression, in three independent series of breast cancer, including a total of 499 patients and 141 events during follow-up. Common statistical tests of associations as well as univariate and multivariate regression analysis of patient survival were used. By counting vessels with actively proliferating endothelium, we show that microvascular proliferation is a significant predictor of disease progression in breast cancer, especially among high-grade and ER-negative tumors. Our findings indicate that this novel marker of active tumor angiogenesis might be of value in patient management and should be further studied in the context of patient selection for anti-angiogenesis treatment.

Increased lymphatic vessel density and lymphangiogenesis in inflammatory bowel disease

BACKGROUND

Involvement of the lymphatic system in inflammatory bowel disease (IBD) has been suggested.

AIMS

To examine the density and distribution of lymphatic vessels (LV) within inflamed and non-inflamed wall sections of IBD patients compared with controls, and to evaluate expression of major lymphangiogenic factors.

METHODS

Ileal and colon specimens of 22 patients with Crohn's disease (CD), 16 patients with ulcerative colitis (UC) and 11 controls were studied. Quantification of LV was performed using immunohistochemistry with podoplanin and D2-40 antibodies on seven randomly selected fields. Mucosal expression of podoplanin and lymphangiogenic factor mRNA was measured using PCR.

RESULTS

In CD patients, lymphatic density was significantly increased in non-inflamed and inflamed ileal (P < 0.01 and P < 0.001) and colonic (P < 0.01 and P < 0.001) mucosa compared to controls. Podoplanin mRNA levels were similar in non-inflamed mucosal areas and controls, whereas a four- and sixfold increase was seen in inflamed ileal and colonic areas (P < 0.05). In UC, lymphatic density increased fourfold in non-inflamed (P < 0.001) and fivefold in inflamed colonic mucosa (P < 0.001) compared with controls. An increase in podoplanin mRNA levels was seen in both non-inflamed and inflamed areas (P < 0.01) compared with controls. In CD and UC, lymphatics were found throughout the inflamed mucosa, including the upper half of the lamina propria. Expression of lymphangiogenic factors was similar in patients and controls.

CONCLUSIONS

Increased density of lymphatic vessels is a constant feature of IBD and is present in non-inflamed areas. It is transmural in CD and confined to the mucosa in UC. Its origin remains unclear.

Expressão imunohistoquímica do marcador tumoral CD34 e P27 como fator prognóstico em adenocarcinoma de próstata clinicamente localizado após prostatectomia radical

OBJETIVO: Analisar a expressão imunoistoquímica do marcador CD34 e p27, como fator prognóstico em pacientes com neoplasia de próstata localizada. MÉTODOS: Análise de 100 casos de pacientes portadores de neoplasia prostática localizada submetida à cirurgia curativa. Realizou-se o preparo histológico habitual, seguido da reação imunoistoquímica para a detecção do acúmulo da proteína CD34 e p27 seguida de análise estatística. RESULTADOS: Na avaliação do marcador P27 e na correlação com as variáveis, observou-se diferença significativa no escore de Gleason com expressão positiva (P27 positivo) relacionada com PSA médio mais baixo (p=0,091), escore de Gleason mais baixo (p<0,0001) e menor área de tumor no CD34 (p=0,036). Correlacionando-se o marcador CD34 na área tumoral observou-se quanto menor o CD34 positivo menor é o valor do PSA (p<0,0001), e menor é o escore de Gleason (r=0,5726 ; p<0,0001) e quanto maior o CD34 positivo maior é o estadiamento (r=0,3305 ; p<0,0001) e a chance de recidiva (p=0,002). Os pacientes com estadiamento mais alto, também tinham maior área CD34 positivo (p<0,0001). CONCLUSÃO: Os marcadores P27 e CD34 estão associados com os eventos próprios ao câncer de próstata; contudo, apenas o CD34 foi capaz de determinar a possibilidade de recidiva bioquímica.

Tumor angiogenesis as an early marker of long-term prostate cancer mortality

Evaluation of: Mucci LA, Powolny A, Giovannucci E et al.: Prospective study of prostate tumor angiogenesis and cancer-specific mortality in the health professionals follow-up study. J. Clin. Oncol. 27, 5627–5633 (2009). Most prostate cancer patients are diagnosed with localized disease. Long-term prostate cancer mortality is low, and many patients have been overtreated. Better prediction tools are needed to distinguish clinically insignificant, low-risk prostate cancers from lethal diseases. Tumor microvessel density, a marker of angiogenesis, has been shown to be related to the development of prostate cancer metastasis and even mortality. Mucci et al. found that morphologic characteristics of tumor microvessels, such as vessel size and irregularity, from prostatectomy specimen may be better than microvessel density as indicators of active angiogenesis, cancer aggressiveness and metastatic potential, and potentially prostate cancer-specific mortality. Prognostic tools combining angiogenesis biomarkers and clinical features led to marked improvement in the prediction of lethal prostate cancer. If these results are confirmed with studies from prostate biopsy samples, this novel prognosis tool will be of significant importance to guide clinical decision-making for localized prostate cancer.

Prospective study of prostate tumor angiogenesis and cancer-specific mortality in the health professionals follow-up study

PURPOSE

Tumor growth requires the development of independent vascular networks that are often primitive in morphology and function. We examined whether microvessel morphology contributes to the considerable biologic heterogeneity of prostate cancer.

METHODS

We evaluated microvessel morphology as a predictor of prostate cancer mortality among 572 men in the Health Professionals Follow-Up Study diagnosed with cancer during 1986 to 2000. We immunostained prostatectomy tumor block sections for endothelial marker CD34 and assessed microvessel density, vessel size (area and diameter), and irregularity of vessel lumen using image analysis. Proportional hazards models were used to assess microvessel density and morphology in relation to lethal prostate cancer.

RESULTS

Poorly differentiated tumors exhibited greater microvessel density, greater irregularity of the vessel lumen, and smaller vessels. During 20 years of follow-up, 44 men developed bone metastases or died of cancer. Men with tumors exhibiting the smallest vessel diameter, based on quartiles, were 6.0 times more likely (95% CI, 1.8 to 20.0) to develop lethal prostate cancer. Men with the most irregularly shaped vessels were 17.1 times more likely (95% CI, 2.3 to 128) to develop lethal disease. Adjusting for Gleason grade and prostate-specific antigen levels did not qualitatively change the results. Microvessel density was not linked to cancer-specific mortality after adjusting for clinical factors.

CONCLUSION

Aggressive tumors form vessels that are primitive in morphology and function, with consequences for metastases. Vascular size and irregularity reflect the angiogenic potential of prostate cancer and may serve as biomarkers to predict prostate cancer mortality several years after diagnosis.

Dynamic contrast-enhanced MR imaging in the evaluation of patients with prostate cancer

Prostate cancer is a common tumor among men, with increasing diagnosis at an earlier stage and a lower volume of disease because of screening with prostate-specific antigen (PSA). The need for imaging of the prostate stems from a desire to optimize treatment strategy on a patient and tumor-specific level. The major goals of prostate imaging are (1) staging of known cancer, (2) determination of tumor aggressiveness, (3) diagnosis of cancer in patients who have elevated PSA but a negative biopsy, (4) treatment planning, and (5) the evaluation of therapy response. This article concentrates on the role of dynamic contrast-enhanced MR imaging in the evaluation of patients who have prostate cancer and how it might be used to help achieve the above goals. Various dynamic contrast enhancement approaches (quantitative/semiquantitative/qualitative, high temporal versus high spatial resolution) are summarized with reference to the relevant strengths and compromises of each approach.

Prostate MR imaging: tissue characterization with pharmacokinetic volume and blood flow parameters and correlation with histologic parameters

PURPOSE

To prospectively determine whether pharmacokinetic magnetic resonance (MR) imaging parameters correlate with histologic mean vessel density (MVD), mean vessel area (MVA), and mean interstitial area (MIA) and whether these parameters enable differentiation of prostate cancer, chronic prostatitis, and normal prostate tissue.

MATERIALS AND METHODS

This study was approved by the institutional review board, and informed consent was obtained from all patients. Thirty-five patients with biopsy-proved prostate cancer were examined with a dynamic contrast material-enhanced inversion-prepared dual-contrast gradient-echo sequence (temporal resolution, 1.65 seconds) at 1.5 T to calculate blood volume, interstitial volume, and blood flow. These parameters were correlated with MVD, MVA, and MIA in 95 areas (prostate cancer, n = 36; chronic prostatitis, n = 27; normal prostate tissue, n = 32). For each MR area, five 1-mm(2) squares (original magnification, x100) of the matching histologic area were analyzed. The Wilcoxon signed-rank test was used for statistical analysis.

RESULTS

Blood volume correlated poorly with MVD (Spearman correlation coefficient, 0.252; P = .014) but did not correlate at all with MVA (P = .759). Interstitial volume did not correlate with MIA (P = .507). Blood volume differed between patients with prostate cancer and those with a normal prostate (1.49% vs 0.84%, respectively; P < .001). Interstitial volume differed between patients with chronic prostatitis and those with a normal prostate (39.00% vs 22.59%, respectively; P = .022). Blood flow differed between patients with prostate cancer and those with a normal prostate (0.97 mL/[cm(3) x min(-1)] vs 0.34 mL/[cm(3) x min(-1)], respectively; P < .001), between patients with prostate cancer and those with chronic prostatitis (0.97 mL/[cm(3) x min(-1)] vs 0.60 mL/[cm(3) x min(-1)], respectively; P = .026), and between patients with chronic prostatitis and those with a normal prostate (0.60 mL/[cm(3) x min(-1)] vs 0.34 mL/[cm(3) x min(-1)], respectively; P = .023).

CONCLUSION

Blood volume and interstitial volume did not reliably correlate with the histologic parameters. Only blood flow enabled differentiation of prostate cancer, chronic prostatitis, and normal prostate tissue.