Glomeruloid Microvascular Proliferation Research Articles

The specific shapes of capillaries are associated with worse prognosis in patients with invasive breast cancer.

Angiogenesis is considered essential for tumor progression; however, whether histological counting of blood vessel numbers, expressed as microvessel density (MVD), can be a prognostic factor in breast cancer remains controversial. It has been suggested that the specific morphology of blood vessels such as glomeruloid microvascular proliferation (GMP) is associated with clinical parameters. Here, we aimed to clarify the significance of MVD with revised immunohistochemistry and to identify new blood vessel shapes that predict prognosis in breast cancer. Four hundred and eleven primary breast cancer specimens were collected, and the sections were immunohistochemically stained with CD31 (single staining) and CD31 and Collagen IV (double staining). The prognosis of patients was examined based on the MVD value, and the presence of GMP and other blood vessels with other specific shapes. As a result, high MVD value and the presence of GMP were not associated with worse prognosis. By contrast, patients with deep-curved capillaries surrounding tumor cell nests (C-shaped) or excessively branched capillaries near tumor cell nests showed a significantly poor prognosis. The presence of these capillaries was also correlated with clinicopathological parameters such as Ki-67 index. Thus, the morphology of capillaries rather than MVD can be a better indicator of tumor aggressiveness.

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.

Intracranial myxoid mesenchymal tumour with EWSR1-ATF1 fusion mimicking high grade glioma

Abstract Aims Molecular profiling is increasingly used in the diagnosis of CNS and non-CNS neoplasms. More than a quarter of all soft tissue tumours are characterized by specific recurrent chromosomal translocations which can be used as molecular signatures. With increasing frequency, EWSR1 rearrangements are found on both mesenchymal tumours and primary glial/neuronal tumours. Here we present a case of intracranial myxoid mesenchymal tumour (IMMT), a rare tumour which is becoming more recognised in recent years, affecting mainly children and young adults, and rarely older adults. It can be found in intraaxial and extraaxial location, with frequent dural connection. The tumour is defined by the genetic hallmark of EWSR1-CREB family gene fusion. Including our case, 16 intracranial tumours with this gene fusion have been reported to date. Our goal is to contribute further to the characterisation of the morphological spectrum, fusion partners and biological behaviour of rare EWSR1-CREB (non-ETS)-rearranged tumours of the CNS. Method Case: The patient is a 27 year old woman with a frontal lobe lesion, radiologically described as a tumour with dural attachment. She underwent surgical debulking, and tumour tissue was histologically examined with conventional immunohistochemistry. Additional genetic testing included targeted mutation screening, FISH, EPIC (Illumina BeadChip) methylation array and next generation sequencing. Histology showed a mitotically active neoplasm with relatively uniform cells, round nuclei and oligodendroglioma-like clear cell change, but no myxoid change. Glomeruloid microvascular proliferation and large areas of tumour necrosis were present. Immunohistochemistry was focally positive for GFAP, and negative or normal for synaptophysin, IDH1 R132H mutation, ATRX and p53. The ki-67 index reached ~20%. Sequencing of IDH1 and IDH2 did not reveal rare IDH mutations, and FISH did not show 1p19q codeletion. Testing for BRAF V600 mutation was negative. Results Although the histology initially suggested a diagnosis of oligodendroglioma, the integrated diagnosis was compatible with glioblastoma, IDH wildtype. Methylation array analysis by EPIC array did not result in classification of currently known entities, neither confirming glioblastoma, nor providing a new diagnosis, when analysed on both brain tumour and sarcoma classifier. This suggested a novel tumour entity not yet represented in the classifier algorithm. Additional testing including next generation sequencing revealed EWSR1 gene rearrangement with fusion partner ATF1 (EWSR1-ATF1 fusion). Based on this, the diagnosis was revised to the emerging new entity of ‘intracranial myxoid mesenchymal tumor’ (IMMT) characterised by EWSR1 fusion with members of the cAMP response element binding protein (CREB) family (ATF1, CREB1 and CREM). Subsequent immunohistochemistry demonstrated positive staining for CD99 and EMA but not desmin. The patient underwent various oncological treatments and is recurrence-free 3 years after initial diagnosis. Conclusion Histologically, IMMT demonstrates a spectrum of features that overlaps with other tumours, but often displays circumscribed growth, uniform cellularity, cytoplasmic clearing and variable myxoid change. The clinical behaviour of these tumours is not fully understood, however provisionally considered intermediate grade. EWSR1-CREB family fusion is not specific but shared with a diverse group of extracranial tumours including soft tissue, salivary gland, odontogenic and myoepithelial tumours. Therefore, clinico-radiologico-pathological correlation is essential to achieve the final diagnosis, and ensure the absence of a primary tumour elsewhere. Familiarisation with IMMT, its characteristic genetic profile and its as yet underreported natural course is crucial, as it can clinically mimic other intracranial tumours such as malignant meningioma or glioma but appears to behave less aggressively than high grade glioma. It is also important to further our understanding of its optimal treatment through review of larger case series and global comparison of patient management.

Baseline microvessel density predicts response to neoadjuvant bevacizumab treatment of locally advanced breast cancer

A subset of breast cancer patients benefits from preoperative bevacizumab and chemotherapy, but validated predictive biomarkers are lacking. Here, we aimed to evaluate tissue-based angiogenesis markers for potential predictive value regarding response to neoadjuvant bevacizumab treatment in breast cancer. In this randomized 1:1 phase II clinical trial, 132 patients with large or locally advanced HER2-negative tumors received chemotherapy ± bevacizumab. Dual Factor VIII/Ki-67 immunohistochemical staining was performed on core needle biopsies at baseline and week 12. Microvessel density (MVD), proliferative microvessel density (pMVD; Factor VIII/Ki-67 co-expression), glomeruloid microvascular proliferation (GMP), and a gene expression angiogenesis signature score, were studied in relation to pathologic complete response (pCR), clinico-pathologic features and intrinsic molecular subtype. We found that high baseline MVD (by median) significantly predicted pCR in the bevacizumab-arm (odds ratio 4.9, P = 0.012). High pMVD, presence of GMP, and the angiogenesis signature score did not predict pCR, but were associated with basal-like (P ≤ 0.009) and triple negative phenotypes (P ≤ 0.041). pMVD and GMP did also associate with high-grade tumors (P ≤ 0.048). To conclude, high baseline MVD significantly predicted response to bevacizumab treatment. In contrast, pMVD, GMP, and the angiogenesis signature score, did not predict response, but associated with aggressive tumor features, including basal-like and triple-negative phenotypes.

Glomeruloid Microvascular Proliferation, Desmoplasia, and High Proliferative Index as Potential Indicators of High Grade Canine Choroid Plexus Tumors.

Choroid plexus tumors (CPT) are intraventricular neoplasms accounting for 10% of all primary central nervous system tumors in dogs. They are frequently classified according to the human WHO classification into choroid plexus papilloma (CPP, grade I), atypical CPP (aCPP, grade II), and choroid plexus carcinoma (CPC, grade III). Histological features observed in canine CPT such as increased vascular density (IVD) and glomeruloid microvascular proliferation (GMVP) are not part of the WHO classification. This multi-centric study aimed to investigate tumor-associated vascular hyperplasia in dogs by determining the prevalence of GMVP and IVD in 52 canine CPT and their association with tumor grade. In addition, the expression of angiogenic factors was assessed by immunohistochemistry in 25 tumors to investigate the pathogenesis of tumor-associated vascular hyperplasia. Based on the classical histological hallmarks, this study of 52 CPT identified 22 (42%) CPP (grade I) and 30 of (58%) CPC (grade III). GMVP was more prevalent in CPC (13/30; 43%) than CPP (1/22; 4%), whereas IVD occurred to a similar extent in CPP and CPC. Desmoplasia was more common in CPC (19/30; 63%) than CPP (2/22; 9%), and similarly, the proliferative index (PI) of neoplastic epithelium was significantly higher in CPC (5.14%) than CPP (0.94%). The majority of CPT expressed platelet-derived growth factor (PDGF), PDGFRα, PDGFRβ, and vascular endothelial growth factor (VEGF) irrespective of tumor grade or tumor-associated vascular hyperplasia. These results suggest that tumor-associated GMVP, desmoplasia, and PI may serve as histological indicators of malignancy in CPT.

Impact of Blood Vessel Quantity and Vascular Expression of CD133 and ICAM-1 on Survival of Glioblastoma Patients.

Glioblastoma (GB) is the most angiogenic tumor. Nevertheless, antiangiogenic therapy has not shown significant clinical efficacy. The aim of this study was to assess blood vessel characteristics on survival of GB patients. Surgically excised GB tissues were histologically examined for overall proportion of glomeruloid microvascular proliferation (MP) and the total number of blood vessels. Also, immunohistochemical vascular staining intensities of CD133 and ICAM-1 were determined. Vessel parameters were correlated with patients' overall survival. The survival time depended on the number of blood vessels (p = 0.03) but not on the proportion of MP. Median survival times for patients with low (<median) and high (≥median) number of blood vessels were 9.0 months (95% CI: 7.5–10.5) and 12.0 months (95% CI: 9.3–14.7). Also, median survival times for patients with low (<median) and high (≥median) vascular expression level of CD133 were 9.0 months (95% CI: 8.0–10.1) and 12.0 months (95% CI: 10.3–13.7). In contrast, the staining intensity of vascular ICAM-1 did not affect survival. In multivariate analysis, the number of blood vessels emerged as an independent predictor for longer overall survival (HR: 2.4, 95% CI: 1.2–5.0, p = 0.02). For success in antiangiogenic therapy, better understanding about tumor vasculature biology is needed.

Effects of conventional neoadjuvant chemotherapy for breast cancer on tumor angiogenesis.

The effects of breast cancer conventional chemotherapy on tumor angiogenesis need to be further characterized. Neoadjuvant chemotherapy is an ideal model to evaluate the results of chemotherapy, allowing intra-patient direct comparison of antitumor and antiangiogenic effects. We sought to analyze the effect of neoadjuvant chemotherapy on tumor angiogenesis and its clinical significance in breast cancer. Breast cancer patients (n=108) treated with neoadjuvant sequential anthracyclines and taxanes were studied. Pre- and post-chemotherapy microvessel density (MVD) and mean vessel size (MVS) were analyzed after CD34 immunohistochemistry and correlated with tumor expression of pro- and antiangiogenic factors (VEGFA, THBS1, HIF1A, CTGF, and PDGFA) by qRT-PCR. Angiogenic measures at diagnosis varied among breast cancer subtypes. Pre-treatment higher MVS was associated with triple-negative subtype and more advanced disease. Higher MVS was correlated with higher VEGFA (p=0.003), while higher MVD was correlated with lower antiangiogenic factors expression (THBS1, p<0.0001; CTGF, p=0.001). Increased angiogenesis at diagnosis (high MVS and glomeruloid microvascular proliferation) and higher VEGFA expression were associated with tumor recurrence (p=0.048 and 0.009, respectively). Chemotherapy-induced angiogenic response (defined as decreased MVD) was present in 35.2% of patients. This response correlated with an increase in antiangiogenic factors (THBS1) without changes in VEGFA expression, and it was associated with tumor downstaging, but not with clinical response, pathologic complete response, or prognosis. Global effects of chemotherapy mainly consisted in an increased expression of antiangiogenic factors (THBS1, CTGF), with significant changes neither of tumor VEGFA nor of MVS. Conventionally scheduled neoadjuvant chemotherapy exerts antiangiogenic effects, through an increase in antiangiogenic factors, THBS1 and CTGF, but the expression of VEGFA is maintained after treatment. Better markers of angiogenic response and a better understanding of the cooperation of chemotherapy and antiangiogenic therapy in the neoadjuvant clinical scenario are needed.

ERG is a novel and reliable marker for endothelial cells in central nervous system tumors.

ETS-related gene (ERG) is a transcription factor that has been linked to angiogenesis. Very little research has been done to assess ERG expression in central nervous system (CNS) tumors. We evaluated 57 CNS tumors, including glioblastomas (GBMs) and hemangioblastomas (HBs), as well as two arteriovenous malformations and four samples of normal brain tissue with immunohistochemistry using a specific ERG rabbit monoclonal antibody. In addition, immunostains for CD31, CD34, and α-smooth muscle actin (α-SMA) were performed on all samples. CD31 demonstrated variable and sometimes weak immunoreactivity for endothelial cells. Furthermore, in 1 case of a GBM, CD34 stained not only endothelial cells, but also tumor cells. In contrast, we observed that ERG was only expressed in the nuclei of endothelial cells, for example, in the hyperplastic vascular complexes that comprise the glomeruloid microvascular proliferation seen in GBMs. Conversely, α-SMA immunoreactivity was identified in the abluminal cells of these hyperplastic vessels. Quantitative evaluation with automated methodology and custom Matlab 2008b software was used to calculate percent staining of ERG in each case. We observed significantly higher quantitative expression of ERG in HBs than in other CNS tumors. Our results show that ERG is a novel, reliable, and specific marker for endothelial cells within CNS tumors that can be used to better study the process of neovascularization.

Hyperplasia of pericytes is one of the main characteristics of microvascular architecture in malignant glioma.

ObjectivesTo investigate the role of pericytes in constructing the malformed microvessels (MVs) and participating microvascular architecture heterogeneity of glioma.MethodsForty human glioma tissue samples (WHO grade II-IV) were included in present study. Observation of blood vessel patterns, quantitative analysis of endothelial cells (ECs)- and pericyte-labeled MVs and comparison between malignant grades based on single- or double-immunohistochemical staining. The MV number density (MVND), microvascular pericyte number density (MPND), and microvascular pericyte area density (MPAD) were calculated. The expression of PDGFβ was also scored after immunostaining.ResultsIn grade II glioma, most of tumor MVs were the thin-wall CD34+ vessels with near normal morphology. In addition to thin-wall CD34+ MVs, more thick-wall MVs were found in grade III glioma, which often showed α-SMA positive. Most of MVs in grade IV glioma were in the form of plexus, curled cell cords and glomeruloid microvascular proliferation while the α-SMA+ cells were the main components. The MVs usually showed disordered arrangement, loose connection and active cell proliferation as shown by Ki67 and α-SMA coexpression. With the increase of glioma grades, the α-SMA+ MVND, CD34+ MVND and MPND were significantly augmented although the increase of CD34+ MVND but not MPAD was statistically insignificant between grade III and IV. It was interesting that some vessel-like structures only consist of α-SMA+ cells, assuming the guiding role of pericytes in angiogenesis. The expression level of PDGFβ was upregulated and directly correlated with the MPND in different glioma grades.ConclusionHyperplasia of pericytes was one of the significant characteristics of malignant glioma and locally proliferated pericytes were the main constituent of MVs in high grade glioma. The pathological characteristics of pericytes could be used as indexes of malignant grades of glioma.

Lentiviral-induced high-grade gliomas in rats: the effects of PDGFB, HRAS-G12V, AKT, and IDH1-R132H.

In human gliomas, the RTK/RAS/PI(3)K signaling pathway is nearly always altered. We present a model of experimental gliomagenesis that elucidates the contributions of genes involved in this pathway (PDGF-B ligand, HRAS-G12V, and AKT). We also examine the effect on gliomagenesis by the potential modifier gene, IDH1-R132H. Injections of lentiviral-encoded oncogenes induce de novo gliomas of varying penetrance, tumor progression, and histological grade depending on the specific oncogenes used. Our model mimics hallmark histological structures of high-grade glioma, such as pseudopalisades, glomeruloid microvascular proliferation, and diffuse tumor invasion. We use our model of gliomagenesis to test the efficacy of an experimental brain tumor gene therapy. Our model allowed us to test the contributions of oncogenes in the RTK/RAS/PI(3)K pathway, and their potential modification by over-expression of mutated IDH1, in glioma development and progression in rats. Our model constitutes a clinically relevant system to study gliomagenesis, the effects of modifier genes, and the efficacy of experimental therapeutics.

Mullerian Carcinosarcoma Arising in the Cecum Associated With Florid Vascular Proliferation/Glomeruloid Microvascular Proliferation

Angiogenesis is required for tumor growth, and the degree of new vessel formation correlates with adverse prognosis in many types of malignancies. It has now been appreciated that tumor-associated vasculature is heterogenous and sometimes includes a complex vasoformative process that has been termed florid vascular proliferation or glomeruloid microvascular proliferation. These vascular lesions are most characteristic of high-grade gliomas and neuroendocrine tumors but are being increasingly recognized in other types of neoplasias as well. Herein we report a case of carcinosarcoma arising within the cecal wall of a 62-yr-old patient that exhibited florid vascular proliferation, particularly at the time of peritoneal recurrence. Recognition of these tumor-associated vasoformative lesions may be important in view of their adverse prognostic association and may become therapeutically relevant considering the current developments in angiogenesis inhibitors.

Lipocalin 2 expression is associated with aggressive features of endometrial cancer

BackgroundIncreased expression of lipocalin 2 (LCN2) has been observed in several cancers. The aim of the present study was to investigate LCN2 in endometrial cancer in relation to clinico-pathologic phenotype, angiogenesis, markers of epithelial-mesenchymal transition (EMT), and patient survival.MethodsImmunohistochemical staining was performed using a human LCN2 antibody on a population-based series of endometrial cancer patients collected in Hordaland County (Norway) during 1981-1990 (n = 256). Patients were followed from the time of primary surgery until death or last follow-up in 2007. The median follow-up time for survivors was 17 years. Gene expression data from a prospectively collected endometrial cancer series (n = 76) and a publicly available endometrial cancer series (n = 111) was used for gene correlation studies.ResultsExpression of LCN2 protein, found in 49% of the cases, was associated with non-endometrioid histologic type (p = 0.001), nuclear grade 3 (p = 0.001), >50% solid tumor growth (p = 0.001), ER and PR negativity (p = 0.028 and 0.006), and positive EZH2 expression (p < 0.001). LCN2 expression was significantly associated with expression of VEGF-A (p = 0.021), although not with other angiogenesis markers examined (vascular proliferation index, glomeruloid microvascular proliferation, VEGF-C, VEGF-D or bFGF2 expression). Further, LCN2 was not associated with several EMT-related markers (E-cadherin, N-cadherin, P-cadherin, β-catenin), nor with vascular invasion (tumor cells invading lymphatic or blood vessels). Notably, LCN2 was significantly associated with distant tumor recurrences, as well as with the S100A family of metastasis related genes. Patients with tumors showing no LCN2 expression had the best outcome with 81% 5-year survival, compared to 73% for intermediate and 38% for the small subgroup with strong LCN2 staining (p = 0.007). In multivariate analysis, LCN2 expression was an independent prognostic factor in addition to histologic grade and FIGO stage.ConclusionIncreased LCN2 expression is associated with aggressive features and poor prognosis in endometrial cancer.

Glomeruloid microvascular proliferation is associated with lack of response to chemotherapy in breast cancer

Background:Glomeruloid microvascular proliferation (GMP), a novel histology-based angiogenesis marker, has been associated with decreased survival in several human cancers.Methods:In this study, we evaluated the ability of GMP to predict clinical response to neoadjuvant chemotherapy in a series of locally advanced breast cancers (n=112).Results:Presence of GMP (21% of the cases) was significantly associated with high-grade tumours and TP53 mutations in addition to the basal-like and HER2 subtypes of breast cancer as defined by gene expression data. GMP was correlated to a gene expression signature for tumour hypoxia response. The GMP pattern was also significantly associated with lack of treatment response and progressive disease (P=0.004).Interpretation:The findings suggest that GMP might be able to predict the lack of response to neoadjuvant chemotherapy in locally advanced breast cancer. Whether GMP may be an independent predictor compared with other factors including TP53 mutation status and tumour grade needs confirmation in larger studies.

Prominent Microvascular Proliferation in Clinically Aggressive Neuroblastoma

Tumor vasculature is disorganized and glomeruloid microvascular proliferation (MVP) has been identified as a poor prognosticator in some adult cancers. To determine the clinical significance of MVP, including glomeruloid MVP in neuroblastoma, we initially examined vessel architecture in tumor sections from 51 children diagnosed at Children's Memorial Hospital (CMH) and subsequently evaluated 154 neuroblastoma tumors on a tissue microarray constructed at Children's Hospital of Philadelphia (CHOP). H&E sections were examined for the presence of structurally abnormal vessels and further characterized by immunostaining for CD31 and von Willebrand factor to highlight endothelial cells and alpha-smooth muscle actin for pericytes. Tumors with thickened walls containing a complete layer of hypertrophic endothelial cells plus additional layers of vascular mural cells were classified as MVP positive. Associations between MVP and established clinicopathologic features and outcome were assessed. In both series, MVP was significantly associated with Schwannian stroma-poor histology (CMH, P = 0.008; CHOP, P < 0.001) and decreased survival probability (CMH, P = 0.017; CHOP, P = 0.014). In the CHOP series, MVP was associated with high-risk group classification (P < 0.001), although this association was not seen in the smaller CMH cohort. The association between MVP and poor outcome provides further support for the concept that angiogenesis plays an important role in determining the biological behavior of neuroblastoma tumors. Our results also indicate that angiogenesis is regulated differently in Schwannian stroma-rich versus stroma-poor neuroblastoma tumors. Further studies investigating the activity of angiogenic inhibitors in children with clinically aggressive stroma-poor neuroblastoma are warranted.

Expression of enhancer of zeste homologue 2 is significantly associated with increased tumor cell proliferation and is a marker of aggressive breast cancer.

The polycomb group protein enhancer of zeste homologue 2 (EZH2) has been linked to invasive properties of aggressive breast cancer. In this report, tissue microarray analysis of 190 breast carcinomas from a nested case-control study shows that EZH2 is significantly associated with interval breast cancers. Further, a strong relationship was found with tumor cell proliferation (by Ki-67 expression), locally advanced disease, metastasis at presentation, markers of the basal epithelial phenotype (positivity for cytokeratin 5/6 or P-cadherin), and p53 status. EZH2 expression was also significantly associated with glomeruloid microvascular proliferation, an aggressive angiogenic phenotype. For prediction of aggressive disease (any event of locally advanced disease, lymph node spread, or distant spread), EZH2 was the only variable of significance in multivariate analysis, whereas no additional information was given by Ki-67. Although EZH2 expression was significant in univariate survival analysis, only tumor cell proliferation and lymph node status were significant in the final multivariate model. In conclusion, our findings indicate an important relationship not only between EZH2 and markers of tumor cell proliferation but also with aggressive disease. These findings might be practically important and relevant because the polycomb group proteins have recently been suggested as candidates for targeted therapy.

Angiogenesis – recent developments in molecular pathogenesis, morphological markers, and therapeutic applications

Angiogenesis – recent developments in molecular pathogenesis, morphological markers, and therapeutic applications

The prognostic implication of the basal-like (cyclin E high/p27 low/p53+/glomeruloid-microvascular-proliferation+) phenotype of BRCA1-related breast cancer.

Previous studies have shown that BRCA1-related breast cancers are often high-grade tumors that do not express estrogen receptors, HER2, p27(Kip1), or cyclin D1, but do express p53 and cyclin E. In addition, the expression of cytokeratin 5/6 (CK5/6), indicating a basal epithelial phenotype, is frequent in BRCA1-related breast cancer. Here, in a series of 247 breast cancers, we demonstrate that CK5/6 expression was associated with nearly all of the features of BRCA1-related breast cancer and was also associated with a poor prognosis. In a parsimonious multivariable proportional hazards model, protein levels of cyclin E, p27(Kip1), p53, and the presence of glomeruloid microvascular proliferation all independently predicted outcome after breast cancer. In this model, only cyclin E and p27(Kip1) levels were independent predictors in lymph node-negative cancers, whereas glomeruloid microvascular proliferation and tumor size independently predicted outcome in node-positive disease. The molecular determinants of the basal epithelial phenotype encapsulate many of the key features of breast cancers occurring in germ-line BRCA1 mutation carriers and have independent prognostic value. Basal breast cancer deserves recognition as an important subtype of breast cancer.

Reduced Renin Expression and Altered Gene Transcript Profiles in Multicystic Dysplastic Kidneys

Reduced Renin Expression and Altered Gene Transcript Profiles in Multicystic Dysplastic Kidneys

Glomeruloid Microvascular Proliferation Orchestrated by VPF/VEGF: A New World of Angiogenesis Research

One can hardly imagine a more comprehensive investigative assault than that occurring in the field of tumor angiogenesis. Scores of basic and clinical researchers in academics and industry are entrenched in a search for underlying mechanisms and a means for antagonizing the proliferation of new blood vessels in neoplastic diseases with the common goal of selectively inhibiting angiogenesis as an effective therapy for all sorts of cancer. To this end, angiogenesis is being approached from a variety of research angles: genetic, biochemical, molecular biological, transgenic and knockout mouse models, and large scale clinical trials involving anti-angiogenesis regimens in cancer patients. 1,2 In this period of heightened research activity, enthusiasm, and even media coverage, it seems inconceivable that a time existed when angiogenesis research either did not exist or was not fashionable. In fact, the concept of angiogenesis as a key regulator of neoplasia is relatively new, having emerged in the early 1970s. 3 Even after its conceptual birth, meaningful results in angiogenesis research were limited by the experimental model systems available for investigation. Years passed before researchers studying angiogenesis developed model systems that could adequately address their fundamental biological questions. Some have argued that appropriate models are still lacking. 1,4

Quantitative analysis of microvascular changes in diffuse astrocytic neoplasms with increasing grade of malignancy

Because glioblastoma multiforme (GBM) frequently shows striking, glomeruloid microvascular proliferation (MVP), this tumor has become a strong candidate for anti-angiogenic therapy. However, the efficacy of anti-angiogenic treatment may rather be determined by the extent of classic angiogenesis with the formation of delicate microvascular sprouts. Therefore, this study differentially quantifies the microvascular changes in supratentorial diffuse astrocytic neoplasms by computerized image analysis of histological sections in which the microvessels were highlighted by a combined anti-collagen IV/MIB-1 staining. Four microvascular parameters (number, area, perimeter, diameter), the cellularity of the glial tissue, and the MIB-1 labeling index were assessed in biopsies of astrocytoma (A, n = 13), anaplastic astrocytoma (AA, n = 14), and GBM (n = 20), and in normal cerebral cortex (n = 7) and white matter (n = 7). In As and AAs, the microvascular parameters were not significantly different from each other, and the microvascular changes were generally limited compared with WM and CX. In contrast, in GBMs the microvascular parameters were highly variable, and their overall mean value was significantly increased compared with As and AAs (ranging from 1.3× for vessel diameter to 3.3× for vessel area). Our study indicates that not only glomeruloid MVP, but also classic angiogenesis, occurs mainly and only locally in GBMs. Thus, this study provides evidence that As and AAs are not good candidates for anti-angiogenic therapy. The efficacy of such therapy for GBMs awaits further evaluation.