DNA ploidy, nuclear size, proliferation index and DNA-hypomethylation in ovarian cancer.

OBJECTIVE: The present study was undertaken to analyze the impact of epigenetic alterations with a main focus on nuclear area, aneuploidy, hyperploidy, and proliferation in 70 ovarian cancer specimens. METHODS: Morphometric changes and somatic chromosomal ploidy status were assessed by Feulgen spectrophotometry. DNA-hypomethylation of LINE1 repeats was analyzed by means of MethyLight PCR, and methylation levels of satellite 2 (Sat2) and satellite alpha (Satα) DNA sequences in chromosome 1 were measured by Southern blot analysis. These parameters were analyzed with regard to correlations as well as to recurrence and survival. RESULTS: We identified a significant association between LINE1 DNA-hypomethylation and patient age (p=0.029). Furthermore, LINE1 DNA-hypomethylation was positively correlated with the nuclear area (r=0.47; p<0.001) and the proliferation index (r=0.36; p<0.001). Univariate survival analysis showed that the nuclear area and LINE1 DNA-hypomethylation were prognostic factors for overall (p=0.015 and =0.006, respectively) and progression-free survival (p=0.020 and p=0.001 respectively), the percentage of aneuploidy only for overall survival (p=0.031). Subgroup survival analyses revealed that the prognostic value of these factors is strictly confined to mucinous cancers. In serous cancers no prognostic value could be pointed out for any analyzed parameter. Multivariate analysis of the entire cohort showed that the percentage of hyperploidy was an independent prognostic parameter for overall survival (p=0.003) and LINE1 DNA-hypomethylation for progression-free survival (p=0.03). In mucinous cancers nuclear area and LINE1 DNA-hypomethylation were found to be independent predictors of progression-free and overall survival. CONCLUSIONS: In this study we identified the correlations between early cancer-associated genome DNA-hypomethylation, nuclear morphometric changes, somatic chromosomal ploidy status and the proliferation index. Prognostic relevance of nuclear area and LINE1 DNA-hypomethylation was revealed exclusively in mucinous ovarian cancers.

Immunohistochemical profiling of node negative breast carcinomas allows prediction of metastatic risk.

The aim of this study was to identify a prognostic immunohistochemical signature indicative of risk of early metastasis in node-negative breast carcinomas that would also be relevant to the development of new tailored therapy. Quantitative measurements of the immunohistochemical expression of 64 markers (selected from literature data) using high-throughput densitometry (as a continuous variable) of digitised microscopic micro-array images were correlated with clinical outcome in 667 node-negative breast carcinomas (mean follow-up 102 months). Multivariable fractional polynomials model of logistic regression allowed the selection of the best combination of markers (in terms of sensitivity and specificity) to predict patient outcome without any categorisation using predefined cut-points for individual marker measurements. A highly predictive ten-marker (out of 64) signature was identified comprising PI3K, pmTOR, pMAPKAPK-2, SHARP-2, P21, HIF-1alpha, Moesin, p4EBP-1, pAKT and P27 that well classified 91.4% of node-negative patients (specificity 90.9%, sensitivity 93.7%, area under ROC curve 0.958) independently of estrogen receptors (ER), and progesterone receptors (PR) and HER-2 status (91.6% well classified patients when ER, PR, HER-2 excluded). It is concluded that quantitative immunoprofiling of node-negative breast carcinomas is helpful in selecting patients who should not receive aggressive adjuvant chemotherapy and provides data for the development of tailored therapy.

Quantitative immunocytochemical profile to predict early outcome of disease in triple-negative breast carcinomas.

We aimed in this study at identifying prognostic immunohistochemical molecular signatures indicative of disease outcome, also relevant for development of new specific therapies, in triple-negative (ER, PR, c-erbB2- negative) breast carcinoma subtypes. We evaluated 42 markers in tissue micro-arrays from a series of 924 breast carcinomas including 184 triple-negative tumors using standardized quantitative immunocytochemical assays and correlated the data with patients' outcome (mean follow-up of 79 months). When 27/42 markers including basal-like markers first found to be individually significant for prognosis in a univariate analysis (log-rank test) in 924 tumors, were secondly evaluated in the triple-negative tumor subtype (184/924), eleven including maspin, P21, P27, PTEN, caveolin, EGFR, FAK, P38, pMAPK, STAT1 and CD10 were 89.2% predictive of disease outcome in logistic regression. When markers reported in the literature as expressed in basal-like subtype were evaluated in the 924 series, only eight (EGFR, CK14, moesin, caveolin, cMet, ckit, CD44v6, C10) were prognosis predictive in univariate analysis (log-rank test) and in logistic regression were predictive of disease outcome in 66.3% independently of ER, PR and c-erbB2 expression and in 72% in triple-negative tumor subset. The results suggest that the category of 'triple-negative' breast carcinomas does not exactly overlap the basal-like subtype, and that immunoprofiling of triple-negative tumors (not similar to that of basal-like tumors) may be helpful to select patients for more aggressive treatment and provides a basis for development of tailored therapy.

A signature predictive of disease outcome in breast carcinomas, identified by quantitative immunocytochemical assays.

Quantitative immunocytochemical assays of 1,200 breast carcinomas were assessed after construction of tissue microarrays. A total of 42 markers were evaluated for prognostic significance by univariate log rank test (mean follow-up, 79 months), using quantitative scoring by an image analysis device and specific software. Complete data were obtained for 924 patients, for whom 27 of the 42 markers proved to be significant prognostic indicators. Analysis of these 27 markers by logistic regression showed that 18 (cMet, CD44v6, FAK, moesin, caveolin, c-Kit, CK14, CD10, P21, P27, pMAPK, pSTAT3, STAT1, SHARP2, FYN, ER, PgR and c-erb B2), and 15 when ER, PgR and c-erb B2 were excluded, were 80.52% and 78.9% predictive of disease outcome, respectively. The immunocytochemical assays on 4 micron thick sections of fixed tissue are easy to handle in current practice and are cost-effective. Quantitative densitometric measurement of immunoprecipitates by computer-assisted devices from digitized microscopic images allows standardized high-throughput "in situ" molecular profiling within tumors. It is concluded that this 15 marker immunohistochemical signature is suitable for current practice, since performed on paraffin sections of fixed tumor samples, and can be used to select patients needing more aggressive therapy, since this signature is about 80% predictive of poor clinical outcome. Also, the markers included in the signature may be indicative of tumor responsiveness to current chemotherapy or suggest new targets for specific therapies.

[Early breast carcinoma profiling based on quantitative immunocytochemistry can help predict the risk of early distant metastasis]. / Evaluation immunohistochimique du risque métastasique dans les cancers du sein débutants sur microbiopsies.

We examined a series of 667 patients with node-negative breast carcinomas in order to identify prognostic immunohistochemical molecular signatures for the prediction of early metastasis, and potential new therapeutic targets. We used a standardized quantitative immunocytochemical approach with 37 antibodies, based on high-throughput tissue microarrays and image analysis, and analyzed the results with respect to metastatic status after a mean follow-up of 86 months. Complete data were obtained for 586 patients. The predictive value of the markers was first analyzed individually by univariate analysis (log rank test) in 586 node-negative tumors, according to metastatic status during follow-up. Twenty-seven markers had significant prognostic value. ROC curve analysis (logistic regression) was then used to determine the marker combination that best classified the patients with and without metastases. A 15-marker signature (Bcl2, P16, P21, P27, P53, CD34, CA IX, c-kit, FGF-R1, P38, JAK, pSTAT3, CK9, STAT1 and ER) correctly classified 84.8% of the patients (sensitivity 85.5%, specificity 84.6%). When ER, PR and c-erb B2 were excluded from the analysis, a very similar signature, in which CK8-18 replaced ER, correctly classified 83.6% of the patients (sensitivity 84.5%, specificity 83.4%). These results show that quantitative immunoprofiling, independently of ER, PR and c-erb B2 status, can provide a basal-like signature, can properly predict the metastatic risk of node-negative breast carcinomas at diagnostic time. This may be helpful for selecting patients who do not need aggressive adjuvant chemotherapy, and for developing tailored therapies.

[High-throughput quantification of tissue microarrays: identification of candidate target proteins in inflammatory breast cancer]. / La lecture automatisée à haut débit des micro-biopsies en pathologie: mise en évidence de la surexpression de c-Met et PI3K dans les cancers du sein inflammatoire.

Inflammatory breast carcinoma (IBC) is a rare but very aggressive tumour phenotype. Increased c-Met protein expression correlates with reduced survival and a higher metastatic risk in many human malignancies, including breast cancer Several studies have shown that c-Met protein is targetable by specific drugs. Here we compared c-Met expression in IBC (n = 41) and non IBC (n = 480). Two microarrays of IBC and non IBC tissues were constructed and standardized. C-Met, P13K and E-cadherin were immunodetected (Ven-tana Benchmark Autostainer) on serial sections. The results were quantified with an automated image analysis device (SAMBA Technologies) by immunoprecipitate densitometry of each core section (0.6 microns thick). We found that (i) c-Met is significantly overexpressed in IBC compared to non IBC (p < 0. 001), (ii) P13K is also overexpressed (p < 0.001) in IBC, suggesting that overexpressed c-Met is functionally active, at least through the PI3K signal transduction pathway ; and (iii) E-cadherin is paradoxically overexpressed in IBC. We conclude that c-Met may constitute a target for specific therapy in patients with poor-prognosis malignancies like IBC Automated image analysis of TMA is a valuable tool for high-throughput quantification of the immunohistochemical expression of the tumor proteome.

Overexpression of c-Met and of the transducers PI3K, FAK and JAK in breast carcinomas correlates with shorter survival and neoangiogenesis.

c-Met is responsible for cell motility and tumour spreading. c-Met expression and signal transducers reflecting c-Met functionality were investigated in breast carcinomas, in correlation with patient outcome and tumour vasculature. Tissue microarrays of 930 breast carcinomas were constructed, categorised according to patients' follow-up (4- to 10-year follow-up; median, 6.5 years). Standardised immunocytochemical procedures were performed using anti-c-Met, -PI3K, -FAK, -JAK, and -CD146, -FYN and an automated autostainer (Ventana). High-throughput densitometry measuring the extent of immunoprecipitates was assessed by image analysis (SAMBA). c-Met overexpression correlated with poor survival along with PI3K and FAK reflecting c-Met functionality and CD146 and FYN expression in endothelial cells. Automated quantification of immunocytochemical precipitates using image analysis was shown to provide an objective means of measuring cellular proteins that are potentially relevant for current practice in pathological diagnosis and for specific therapy combining inhibitors of both c-Met and downstream transducer pathways, and of tumour angiogenesis.

Poor prognosis in breast carcinomas correlates with increased expression of targetable CD146 and c-Met and with proteomic basal-like phenotype.

Genomic studies have led to new taxonomic classifications of breast carcinomas. Proteomic investigations using tissue microarrays have yielded complementary results and are useful in identifying potential molecular targets for specific therapies. Searching for new drug targets is particularly important for tumors of poor prognosis, such as breast tumors that lack estrogen receptors and HER2 amplification; in these tumors, certain molecules probably play a significant role in tumor spreading through the stromal microvasculature. We investigated 930 breast carcinomas categorized according to patients' survival (range of follow-up = 4-10 years; median follow-up = 6.5 years) using (1) automated immunohistochemical procedures (Ventana, Cedex, France) with tissue microarrays (Alphelys, Plaisir, France) and (2) quantification of immunoprecipitates assessed by automated image analysis densitometry (SAMBA, Meylan, France). Expression of c-Met and CD146 and that of signaling transducers PI3K, FAK, and FYN were compared in living and deceased patients. Expression of some proteins recently reported to be characteristic of basal cell carcinomas was also assessed, namely, CK5-6, caveolin-1, carbonic anhydrase IX, p63, and CD117; these also constitute potential targets for therapies for aggressive tumors. Overexpression of these proteins was observed in deceased or metastatic patients (P < .01 to P < .00001), particularly node-negative patients (except for FYN, p63, and CD146). c-Met and CD146 are involved in tumor spreading, and our results suggest that they probably play an important role in patients' death, along with other proteins involved in hypoxia (carbonic anhydrase IX) and other cell functions or structures (caveolin-1, CD117, CK5-6, and p63) that are expressed in an aggressive subtype of basal cell carcinoma for which no specific therapy is available.

Overexpression of hypoxia-inducible factor HIF-1alpha predicts early relapse in breast cancer: retrospective study in a series of 745 patients.

Hypoxia-inducible factor-1alpha (HIF-1alpha) is a transcription factor that is involved in tumour growth and metastasis by regulating genes involved in response to hypoxia. HIF-1alpha protein overexpression has been shown in a variety of human cancers, but only 2 studies have documented the prognostic relevance of HIF-1alpha expression in breast cancer. The aim of our study was to determine accurately the impact of HIF-1alpha expression on prognosis in a large series (n = 745) of unselected patients with invasive breast cancer in terms of overall survival, local recurrence and distant metastasis risk. HIF-1alpha expression was investigated using immunohistochemical assays on frozen sections, and correlated with patients' outcome (median follow-up = 13.5 years). Univariate (Kaplan-Meier) analysis showed that high levels of HIF-1alpha expression (cutoff = 10%) significantly correlated with poor overall survival (p = 0.019). HIF-1alpha expression correlated with high metastasis risk among the whole group of patients (p = 0.008). Multivariate analysis (Cox model) showed that the HIF-1alpha predictive value was independent of other current prognostic indicators. Moreover among node negative ones, HIF-1alpha expression was also significantly predictive of metastasis risk (p = 0.03) and of relapse (p = 0.035). All the data suggest that HIF-1alpha is associated with a worse prognosis in patients with invasive breast carcinoma. Furthermore HIF-1alpha immunodetection may be considered as a potential indicator for selecting patients who could benefit from specific therapies interfering with HIF-1alpha pathway.

Comparison of the prognosis indication of VEGFR-1 and VEGFR-2 and Tie2 receptor expression in breast carcinoma.

The degree of angiogenesis in breast cancer has previously been shown to be an indicator of prognosis, and tumor microvasculature is a candidate target for new antiangiogenic therapies. The aim of this study was to investigate the prognostic value of vascular endothelial growth factor (VEGF) receptors, VEGFR-1 (Flt-1) and VEGFR-2 (KDR/Flk-1), and Tie2/tek receptor tyrosine kinase in breast carcinoma. VEGF receptors and Tie2 expression was investigated using immunohistochemical assays with monoclonal antibodies on frozen sections in a series of 918 and 909 patients respectively. VEGFR-1 and VEGFR-2 and Tie2 were correlated with long-term (median, 11.3 years) patients' outcome. Univariate (Kaplan-Meier) analysis showed that VEGFR-1 positive tumor surface (cutoff = 5%) was significantly correlated with high metastasis risk (p=0.03) and relapse (p<0.01) in all patients, and in those with node negative tumors (p<0.001 and p<0.01 respectively), but not with overall survival. In contrast Tie2 positive tumor surface (cutoff = 7%) was significantly correlated with poor overall survival (p=0.025) and also with high metastasis risk particularly among node negative patients (p<0.01). Moreover, Tie2 immunoexpression was significantly predictive of relapse (p=0.003) in the node negative subgroup (p=0.02). In multivariate analysis (Cox model), VEGFR-1 and Tie2 immunoexpressions were identified as independent prognostic indicators. In contrast, univariate analysis showed that VEGFR-2 positive tumor surface (cutoff = 10%) was not correlated with survival or with metastasis and relapse risk. Our results suggest that VEGFR-1 and Tie2 immunohistochemical expression permits the identification of patients with poor outcome, and particularly node negative ones with a high risk for metastasis and relapse. VEGFR-1 and Tie2 immunodetection may also be considered as potential tools for selecting patients who could benefit in the future from specific antiangiogenic therapy interfering with VEGFR-1 and Tie2 activation pathways.

Thyroid follicular adenomas may display features of follicular carcinoma and follicular variant of papillary carcinoma.

Thyroid follicular adenomas (FA) are encapsulated tumors lacking vascular, capsular or lymphatic invasion and the typical nuclear features of papillary carcinoma (PC). However, some FA demonstrate nuclear atypia reminiscent of either follicular carcinomas (FC) or follicular variant of papillary carcinomas (FVPC), suggesting they may represent precursors of malignant transformation. We hypothesized that an objective evaluation of nuclear chromatin patterns could be used to define atypical follicular tumors (AFT) that are likely to be premalignant. To test this hypothesis, we used a computer-aided image analysis system to define the chromatin pattern of nuclei from thyroid tumors. To validate the system, we analyzed 3000 nuclei from 10 FA, 10 FC, and 10 FVPC samples and accurately distinguished between these classes of tumors. Then, we analyzed nine AFT and, in parallel, we analyzed the tumors for activating mutations of N2-RAS and over-expression of RET. The predominant chromatin pattern of AFT was of FA type in two cases, FC type in two cases, and PC type in three cases. One case contained similar numbers of FC and PC nuclei and one was comprised of a mixture of the three nuclear types. Neither RAS mutation nor RET overexpression were detected in FA. N2-RAS mutations were found in 33% of AFT, 20% of FC and 20% of FVPC without correlation with chromatin pattern. Over-expression of RET was detected in 45% of AFT, 20% of FC and 50% of FVPC and was correlated with PC nuclei. These results show that AFT are a heterogeneous group of tumors, containing genuine benign tumors and tumors that share morphological and molecular features with follicular and papillary carcinomas that might be precursors of both types of thyroid carcinomas.

Tumor neoangiogenesis by CD31 and CD105 expression evaluation in breast carcinoma tissue microarrays.

PURPOSE: The aim of the study was to evaluate CD31 and CD105 immunohistochemical expressions in tissue microarrays from 360 breast carcinomas. STUDY DESIGN: Computerized (ACIS/Chromavision) assisted image analysis was performed to compare immunoreactions in tissue microarrays with those in current paraffin and frozen sections. We also aimed to determine the CD105 and CD31 prognostic significance and relevance in routine practice by correlating results of immunodetections with patients' (n = 360) outcome (14.3-year follow-up). RESULTS: The results show (a) that in tissue microarrays, the CD31 and CD105 expression quantified by image analysis device did not correlate with the measurements assessed on routine paraffin sections; (b) that CD105 expression is endowed of a prognostic significance in paraffin sections in terms of overall survival (P < 0.01), whereas in contrast, CD31 on paraffin sections did not correlate with patients overall survival; (c) that semiquantitative analysis of CD105 expression correlated with the image analysis measurements in frozen sections (rho = 0.671, P < 0.01) and paraffin (rho = 0.824, P < 0.01) sections. However, paraffin sections were less immunostained than frozen ones. CONCLUSIONS: It is concluded (a) that CD105 may be suitable in paraffin sections to evaluated neoangiogenesis; and (b) that tissue microarrays are not suitable substrates for neoangiogenesis evaluation as a prognostic indicator in breast carcinomas, in contrast to current tissue sections.

Prognostic significance of angiogenesis evaluated by CD105 expression compared to CD31 in 905 breast carcinomas: correlation with long-term patient outcome.

Our purpose was to determine the respective prognostic significance of CD105 and CD31 immunoexpression in node negative patients with breast carcinoma, since angiogenesis induces blood borne metastases and death in carcinomas. CD105 (endoglin) has been reported as expressed by activated endothelial cells and consequently should better reflect neoangiogenesis in malignant tumors. Comparison of CD31 and CD105 immunocytochemical expression was undertaken in a series of 905 breast carcinomas. Results were compared to patients' long-term (median = 11.3 years) outcome. Univariate (Kaplan-Meier) analysis showed that the number of CD105+ microvessels (cut-off 15 vessels) correlated significantly with poor overall survival (p=0.001). This correlation was less significant in node negative patients (p=0.035). The number of CD31+ microvessels (cut-off 25 vessels) similarly correlated with poor survival (p=0.032) but not in the subgroup of node negative patients. Marked CD105 expression also correlated with a high risk for metastasis in all patients (p=0.0002) and in the subset of node negative patients (p=0.001). Similarly metastasis risk in node negative patients correlated with marked CD31 immunocytochemical expression (p=0.02). Multivariate analysis (Cox model) identified CD105, but not CD31 immunoexpression, as an independent prognostic indicator. Our results suggest that: i) in breast carcinomas, immunoselection of microvessels containing activated CD105 labelled endothelial cells is endowed with a stronger prognostic significance, as compared to CD31 vessels labelling; ii) the CD105 immunoexpression may be considered as a potential tool for selecting node negative patients with a poorer outcome and higher metastasis risk; iii) in these patients specific antiangiogenic therapy targeted by anti-CD105 conjugates can be further developed.

Long-term prognostic significance of neoangiogenesis in breast carcinomas: comparison of Tie-2/Tek, CD105, and CD31 immunocytochemical expression.

The immunocytochemical detection of Tie-2/Tek, CD105, and CD31 was assessed in a large series (n = 905) of breast carcinomas on frozen sections. Results were correlated with patients' long-term outcome (median, 11.7 years) to define the respective prognostic significance of these markers. Univariate (Kaplan-Meier) analysis demonstrated that higher expression of CD31 (P = 0.032), CD105 (P = 0.001), and Tie-2/Tek (P = 0.025) correlated with poorer survival. However, only greater CD105 expression could significantly (P = 0.035) identify node-negative patients with poorer survival. Moreover, in multivariate analysis, CD105 and Tie-2/Tek, but not CD31, expression proved to be independent significant prognostic indicators. Marked expression of CD31 (P = 0.024), CD105 (P = 0.001), and Tie-2/Tek (P = 0.01) also correlated with higher risk of metastases in node-negative patients. It is concluded that CD105 immunoexpression in breast carcinomas is an independent prognostic indicator in node-negative patients, better in terms of overall survival than Tie-2/Tek and CD31. Also, Tie-2/Tek expression proved more sensitive than CD31 expression in terms of prognostic significance. Compared with CD31, CD105 and Tie-2/Tek have more clinical relevance for patient monitoring and also can serve as targets for specific therapy, such as CD105 immunotoxins or Tie-2/Tek pathway blockade, as recently suggested in experimental studies.

[Prognostic significance of VEGF receptors, VEGFR-1 (Flt-1) and VEGFR-2 (KDR/Flk-1) in breast carcinoma]. / Valeur pronostique de l'expression des recepteurs du VEGF, VEGFR-1 (FLT-1) et VEGFR-2 (KDR/FLK-1) dans le cancer du sein.

OBJECTIVES: The aim of this study was to investigate the prognostic value of vascular endothelial growth factor (VEGF) receptors, VEGFR-1 (Flt-1) and VEGFR-2 (KDR/Flk-1) in breast carcinoma. METHODS: VEGF receptor expression was investigated using immunohistochemical assays with monoclonal antibodies on frozen sections in a series of 918 patients and was correlated with prognostic parameters and with long-term follow-up (median, 11.3 years). VEGFR-1 and VEGFR-2 immunostained surface was evaluated in percentage of the total tumor specimen surface by light microscopy (x100). RESULTS: VEGFR-1 and VEGFR-2 were strongly expressed in endothelial cells within blood microvessels, and weakly in tumor cells. Univariate (Kaplan Meier) analysis showed that VEGFR-1 positive tumor surface (cut off=5%) was not correlated with survival, but was significantly correlated with high metastasis risk (p=0.03) and relapse (p=0.01) in all patients, and in those with node negative tumors (p=0.001 and p=0.01 respectively). In multivariate analysis (Cox model), VEGFR-1 expression was identified as an independent prognostic indicator. Univariate analysis showed that VEGFR-2 positive tumor surface (cut off=10%) was not correlated with survival or with metastasis risk and relapse. CONCLUSION: Our results show that VEGFR-1 immunohistochemical expression permits the identification of patients with poor outcome, particularly those with node negative tumors, with high risk of metastasis and relapse. VEGFR-1 immunodetection may further be considered as a potential tool for evaluating tumor agressiveness and therapeutic strategies in breast cancer.

CD105 expression is a marker of high metastatic risk and poor outcome in breast carcinomas. Correlations between immunohistochemical analysis and long-term follow-up in a series of 929 patients.

CD105 (endoglin) is expressed significantly in activated endothelial cells in culture and in tumor microvessels. Quantification of CD105 immunocytochemical expression that may be clinically relevant has not been accurately evaluated. We studied CD105 expression on frozen tissue sections by using immunohistochemical assays in a series of 929 patients and correlated the findings with long-term follow-up (median, 11.3 years). Univariate (Kaplan-Meier) analysis showed that the number of CD105+ microvessels (cutoff, 15 vessels) correlated significantly with poor overall survival among all patients (P = .001). This correlation was less significant in node-negative patients (P = .035). Marked CD105 expression also correlated with a high risk for metastasis among all patients (P = .006) and among node-negative patients (P = .001). Multivariate analysis (Cox model) identified CD105 immunodetection as an independent prognostic indicator. Our results suggest that immunohistochemical expression of CD105 has practical clinical relevance for identifying node-negative patients with a poor prognosis. Moreover, immunodetection of CD105 also may be considered a potential tool for selecting patients who could benefit from specific antiangiogenic therapy, using anti-CD105 conjugates.

Platelet accumulation in brain microvessels in fatal pediatric cerebral malaria.

The pathogenesis of fatal cerebral malaria (CM) is not well understood, in part because data from patients in whom a clinical diagnosis was established prior to death are rare. In a murine CM model, platelets accumulate in brain microvasculature, and antiplatelet therapy can improve outcome. We determined whether platelets are also found in cerebral vessels in human CM, and we performed immunohistopathology for platelet-specific glycoprotein, GPIIb-IIIa, on tissue from multiple brain sites in Malawian children whose fatal illness was severe malarial anemia, CM, or nonmalarial encephalopathy. Platelets were observed in 3 locations within microvessels: between malaria pigment and leukocytes, associated with malaria pigment, or alone. The mean surface area of platelet staining and the proportion of vessels showing platelet accumulation were significantly higher in patients with CM than in those without it. Platelet accumulation occurs in the microvasculature of patients with CM and may play a role in the pathogenesis of the disease.

Tie2/Tek expression in breast carcinoma: correlations of immunohistochemical assays and long-term follow-up in a series of 909 patients.

The degree of angiogenesis in breast cancer has previously been shown to be an indicator of prognosis, and tumor microvasculature is at present a candidate target for new antiangiogenic therapies. Tie2/tek receptor tyrosine kinase is a novel marker of microvasculature of solid tumors that appears to play a key role in the angiogenesis process in breast cancer. However the prognostic significance of Tie2 has never been demonstrated in this neoplasm. In order to establish the prognostic value of Tie2 in breast carcinoma, we investigated Tie2 expression in a large series of patients and correlated it with long-term follow-up. Tie2 expression was investigated using immunohistochemical assays with a polyclonal antibody on frozen sections in a series of 909 patients, and was correlated with long-term (median, 11.3 years) follow-up. Univariate (Kaplan-Meier) analysis showed that a large Tie2 positive tumor surface (cut off = 7%) was significantly correlated with poor overall survival (p=0.025). Tie2 expression correlated with high metastasis risk among all patients (p=0.00067) and among node negative ones as well (p=0.01). Tie2 immuno-expression was also significantly predictive of relapse in all patients (p=0.003) and in the node negative subgroup (p=0.02). In multivariate analysis (Cox model) Tie2 immunodetection was identified as an independent prognostic indicator. Our results suggest that Tie2 immunohistochemical expression exhibits practical clinical relevance in terms of prognostic prediction. Tie2 expression permits identification of poor outcome patients, in particular node negative ones with high risk of metastasis and relapse. Tie2 immunodetection may further be considered as a potential tool for selecting patients who could benefit in the future from specific antiangiogenic therapy interfering with Tie2 pathway.

[Effects of progestins on human endometrium in vitro]. / Effets des progestatifs sur l'endomètre humain in vitro.

In order to obtain a better evaluation of the epithelial proliferation of the human endometrium, we developed an "in vitro" model to quantify the effects of hormonal treatments, as an "hormonogram". We particularly aimed to evaluate the effects of steroids used in the replacement hormone therapy during menopausis in the view of predicting and preventing the development of precancerous lesions of the endometrium. This study has evaluated the effects of different progestins currently used in hormone therapy, progesterone, medroxy-progesterone acetate (MPA), nomegestrol acetate (TX), norethindrone acetate (NOR) on human proliferative endometrium explant culture, using two means: prostaglandin F2 alpha (PGF2 alpha) output in medium culture, and immunoexpression of estradiol receptor (ER), progesterone receptor (PR) and proliferative antigen Ki67 in tissue. After culture, quantitative studies on ER or PR immunoexpression could be assessed by image analysis procedure in contrast to Ki67 immunoexpression too weak low in non tumorous endometrium to be quantified. PGF2 alpha output, was decreased by progesterone, TX and MPA in both proliferative endometrium subtypes. With regards to receptor immunoexpression, progesterone only decreased PR expression in proliferative endometrium. PR immunoexpression in stromal cells was decreased by all progestins in homogeneous proliferative endometrium explants. TX decreased PR and ER expression in glands and stroma of homogeneous proliferative endometrium. MPA exhibited similar effects but only on heterogeneous proliferative endometrium. In brief, our results show that in vitro progestative treatment on endometrium reduced PGF2 alpha output and decreased PR and/or ER immunoexpression, although the in vitro effects of each progestin were not similar and varied with the endometrium subtype (proliferative homogeneous or heterogeneous). This study opens new fields of research particularly to investigate the endometrial proliferative activity using explant culture.