Assessment of angiogenesis in breast carcinoma: an important factor in prognosis?

Expression of Von Willebrand factor, an endothelial cell marker, is up-regulated by angiogenesis factors: a potential method for objective assessment of tumor angiogenesis

von Willebrand factor (vWF), a glycoprotein produced uniquely by endothelial cells and megakaryocytes, is routinely used to identify vessels in tissue sections. Vessel density in tumor specimens, as determined by immuno-histochemical staining for vWF or other endothelial cell markers, is a negative prognostic factor for many solid tumors. vWF is heterogeneously distributed throughout the vasculature, transcriptional control in response to the tissue microenvironment being responsible for local variations in endothelial cell levels of vWF. Here, we report that fibroblast growth factor-2 and vascular endothelial growth factor, potent angiogenesis inducers expressed in a variety of tumors, up-regulate expression of vWF mRNA and protein in cultured endothelial cells with a synergistic effect. Our data support the measurement of vWF mRNA in tumors to detect activated endothelium or angiogenesis. For this purpose, we developed a semi-quantitative RT-PCR for vWF mRNA. Preliminary results obtained with specimens from colon carcinoma and the corresponding normal colonic mucosa showed higher vWF mRNA levels in most tumors than in their normal counterparts. The differences in vWF mRNA levels were much larger than the differences in vessel counts between a tumor and the corresponding normal mucosa, indicating that high vWF mRNA levels in tumors may indeed be an early sign of activation of the endothelium. The rapidity, objectivity, sensitivity and specificity of this technique make it suitable for routine clinical application to identify aggressive, highly angiogenic tumors.

Vascular grading of angiogenesis: prognostic significance in breast cancer

The study aimed to evaluate the prognostic value of angiogenesis by vascular grading of primary breast tumours, and to evaluate the prognostic impact of adding the vascular grade to the Nottingham Prognostic Index (NPI). The investigation included 836 patients. The median follow-up time was 11 years and 4 months. The microvessels were immunohistochemically stained by antibodies against CD34. Angiogenesis was graded semiquantitatively by subjective scoring into three groups according to the expected number of microvessels in the most vascular tumour area. The vascular grading between observers was moderately reproduced (kappa = 0.59). Vascular grade was significantly associated with axillary node involvement, tumour size, malignancy grade, oestrogen receptor status and histological type. In univariate analyses vascular grade significantly predicted recurrence free survival and overall survival for all patients (P < 0.0001), node-negative patients (P < 0.0001) and node-positive patients (P < 0.0001). Cox multivariate regression analysis showed that vascular grading contributed with independent prognostic value in all patients (P < 0.0001). A prognostic index including the vascular grade had clinical impact for 24% of the patients, who had a shift in prognostic group, as compared to NPI, and implied a better prognostic dissemination. We concluded that the angiogenesis determined by vascular grading has independent prognostic value of clinical relevance for patients with breast cancer.

New Prognostic Factors Associated with Long-term Survival in Node-Negative Breast Cancer Patients

BACKGROUND: This study was undertaken to determine the absolute and relative value of angiogenesis, proliferating cell nuclear antigen (PCNA) and conventional prognostic factors in predicting relapse-free survival (RFS) and overall survival (OS) rates associated with long-term survival in Japanese patients with node-negative breast cancer. PATIENTS AND METHODS: Two hundred patients with histological node-negative breast cancer were studied. We investigated nine clinicopathological factors, including angiogenesis, PCNA using per-manent-section immunohistochemistry, clinicaltumor size, histological grade (HG), tumor necrosis, lymphatic vessel invasion (LVI), histological extension, histological classification, and infiltrating growth (INF), followed for a median of 10 years (range, 1 to 20). RESULTS: Twenty-one patients (10.5%) had recurrence and 15 patients (7.5%) died of breast cancer. Univariate analysis showed that PCNA, clinical tumor size, HG, angiogenesis, and LVI were significantly predictive of 20-year RFS or OS. Tumor necrosis was significantly predictive of OS, not of RFS. Multi-variate analysis showed that clinical tumor size (P = 0.0003), angiogenesis (P = 0.0003), PCNA (P = 0.0064), and HG (P = 0.0401) were significant independent prognostic factors for RFS. PCNA (P< 0.0001) and clinical tumor size (P = 0.0112) were significant independent prognostic factors for OS, while angiogenesis was a borderline significant factor. CONCLUSION: PCNA and angiogenesis were important new prognostic factors in node-negative breast cancer patients.

Predictors of axillary lymph node metastases in patients with invasive breast carcinoma by a combination of classical and biological prognostic factors

The presence of axillary lymph node metastases (ALNMs) is the most important prognostic factor in breast carcinoma. If ALNMs were predictable without performing axillary lymph node dissection (ALND), this procedure would not be necessary in selected patients. Using a combination of some of the new biological markers with the classical ones, our objective was I) to identify the best set of predictors of ALNMs, and II) to define predictive models with either high or low probability of ALNMs. We studied 102 patients with invasive breast carcinoma. All patients underwent ALND, and at least 10 axillary lymph nodes per case were obtained. In the primary tumour we evaluated size, histological subtype and grade, lymphatic/vascular invasion and margin. Hormone receptor status, MIB1 index, microvessel density, c-erbB-2 and cathepsin D expression were assessed by immunohistochemistry, and DNA ploidy and S-phase by flow cytometry. Risk factors for ALNMs were estimated by nonlinear logistic regression analysis. The best predictors of ALNMs were: tumour size > 2 cm [OR 6.45, 95% confidence interval (CI) 21.74 to 1.91], presence of lymphatic/vascular invasion [OR 4.95, CI (14.50 to 1.69)], infiltrative margin [OR 9.87 CI (37.44 to 2.60)] and high MIB-1 index [OR 8.39, CI (33.47 to 2.10)]. Two subsets had a very high risk of ALNMs: I) tumour size > 2 cm, with lymphatic/vascular invasion and infiltrative margin; 26 (89.66%) of 29 patients of this subgroup had ALNMs, and (II) tumour size > 2 cm, with lymphatic/vascular and high MIB1 index.; eight of the nine (89%) patients of this subgroup had ALNMs. We could also identify a two-variable model with a very low risk of ALNMs constituted by tumour with circumscribed margin and low MIB-1 index. Of the 19 patients showing these features, only 1 (5.26%) had ALNMs. Therefore, pathological features of the primary tumour can help to assess the risk for ALNM in invasive breast carcinoma. Such risk assessment might avoid regional surgical overtreatment.

Quantification of microvessel density of breast carcinoma: an assessment of the inter- and intraobserver variation

The density profile of microvessels (MVD) has recently emerged as a prognostically independent morphological marker of various malignancies, including carcinoma of the breast. MVD-scoring may thus afford the pathologist the opportunity to identify subsets of early stage breast cancer patients, which may benefit from adjuvant therapy. Reproducibility studies are, however, mandatory. Fifty sections of invasive breast carcinoma, immunolabelled for Factor VIII-related antigen, were scored independently by two observers for the number of vessel-profiles (v-p) in the following manner: 1) 250 randomly selected high power fields (HPF) were scored by two analysts to evaluate the agreement of the counting per se; and 2) the hot spot(s), i.e. the zones considered the most vessel rich, in the 50 sections were identified and scored twice to evaluate the agreement on selecting hot spots. When the observers evaluated MVD in the very same 250 HPF a median deviation of 2 v-p (10%) was produced. The interobserver disparity was further accentuated when the participants independently had to identify the hot spots with a median deviation of 6 v-p (13%). Intraobserver variation was approximately equal to the interobserver discordance. Divergences were most conspicuous in fields with a complex vasculature. In conclusion the v-p scoring resulted in substantial inter- and intraobserver variation both in selecting hot spots and in performing the scoring per se. Alternative-scoring techniques, including strict stereological principles, should be considered in the morphological evaluation of angiogenesis.

Pathophysiologic basis of contrast enhancement in breast tumors

While the diagnostic benefits of gadolinium (Gd)-chelate contrast agents are firmly established in magnetic resonance imaging (MRI) of tumors, the pathophysiologic basis of the enhancement observed and its histopathologic correlate remained vague. Tumor angiogenesis is fundamental for growth and metastasis and also of interest in new therapeutic concepts. By correlative analysis of a) histology; b) vascular density (CD31); and c) vascular permeability (vascular permeability factor/vascular endothelial growth factor [VPF/VEGF]), we found a) significantly (P < 0.001) faster exchange rates in malignant compared with benign breast lesions; b) distinct differences in enhancement characteristics between the histologic types (invasive ductal carcinoma, invasive lobular carcinoma, and ductal carcinoma in situ); and c) dependence of enhancement kinetics on the VPF/VEGF expression. The pathophysiologic basis for the differences in contrast enhancement patterns of tumors detectable by MRI is mainly due to vascular permeability, which leads to more characteristic differences than vascular density. MRI is able to subclassify malignant breast tumors due to their different angiogenetic properties.

Measurement of vascularity as a diagnostic and prognostic tool for well differentiated thyroid tumours: comparison of different methods of assessing vascularity

AIMS

To determine whether the measurement of vascularity can be used to differentiate follicular adenomas from follicular carcinomas or to reflect the prognosis of follicular carcinomas and papillary carcinomas of the thyroid gland, and to compare four methods of assessing vascularity.

METHODS

Tissue sections from 26 papillary carcinomas, 15 follicular adenomas, and 15 follicular carcinomas were stained with an antibody to CD34. A computerised image analysis system was used to calculate, for each tumour, mean endothelial areas and the mean endothelium to tumour epithelial nucleus area ratio from 10 systematically selected fields across one dimension of the tumour ("systematic field" analysis) or from the three most vascularised fields of the tumour ("hot spot" analysis). A European Organisation for Research on Treatment of Cancer (EORTC) prognostic index was calculated for each papillary carcinoma and follicular carcinoma.

RESULTS

Significant differences in vascularity between the three tumour groups could only be shown by comparing mean endothelial area values measured from hot spots. While the hot spot median mean endothelial area of follicular carcinomas was significantly greater than that of follicular adenomas, there was a large overlap between the two groups. For follicular carcinomas, higher hot spot mean endothelial area values were related to worse prognosis as indicated by the EORTC prognostic indices. No association between vascularity and prognosis was found for the papillary carcinomas, regardless of the method of assessing vascularity.

CONCLUSIONS

Measuring endothelial area from hot spots using a computerised image analysis system is a sensitive method of assessing the vascularity of thyroid tumours. While vascularity measurement cannot be recommended as a practical tool for differentiating between malignant and benign follicular tumours, the suggestion that vascularity may reflect prognosis for follicular carcinomas deserves further study.

The relationship between prognostic and predictive factors in the management of breast cancer

The discovery of new prognostic factors proceeds at a much more rapid pace than our knowledge of how to properly utilize this information in the management of patients with breast cancer, especially those with early breast cancer that has not metastasized to regional lymph nodes. Prognostic factors provide information on how the patient is likely to do regardless of treatment. Predictive factors provide information on whether a patient is likely to benefit from therapy. Most factors identified to date provide prognostic information, but relatively few provide information that is truly helpful in making a therapeutic decision in the management of individual patients. In large part this is because there has been insufficient study of the factor, especially prospective evaluations of the factor. Unfortunately this has resulted in the premature use of this information under the general rubric that patients with a poor prognosis deserve more treatment in spite of the fact that there may be no benefit from that therapy in the poor prognostic group.

Fully automated microvessel counting and hot spot selection by image processing of whole tumour sections in invasive breast cancer

BACKGROUND

Manual counting of microvessels is subjective and may lead to unacceptable interobserver variability, which may explain conflicting results.

AIMS

To develop and test an automated method for microvessel counting and objective selection of the hot spot, based on image processing of whole sections, and to compare this with manual selection of a hot spot and counting of microvessels.

METHODS

Microvessels were stained by CD31 immunohistochemistry in 10 cases of invasive breast cancer. The number of microvessels was counted manually in a subjectively selected hot spot, and also in the same complete tumour sections by interactive and automated image processing methods. An algorithm identified the hot spots from microvessel maps of the whole tumour section.

RESULTS

No significant difference in manual microvessel counts was found between two observers within the same hot spot, and counts were significantly correlated. However, when the hot spot was reselected, significantly different results were found between repeated counts by the same observer. Counting all microvessels manually within the entire tumour section resulted in significantly different hot spots than manual counts in selected hot spots by the same observer. Within the entire tumour section no significant differences were found between the hot spots of the manual and automated methods using an automated microscope. The hot spot was found using an eight connective path search algorithm, was located at or near the border of the tumour, and (depending on the size of the hot spot) did not always contain the field with the largest number of microvessels.

CONCLUSIONS

The automated counting of microvessels is preferable to the manual method because of the reduction in measurement time when the complete tumour is scanned, the greater accuracy and objectivity of hot spot selection, and the possibility of visual inspection and relocation of each measurement field afterwards.

Prognostic value of vascular density and cell proliferation in breast cancer patients

We measured microvessel density and cell proliferation index in 84 breast cancers using survival analysis to find out their prognostic value. Immunohistochemistry was applied using antibody to factor VIII-related antigen as a marker for microvessels and MIB-1 antibody to stain proliferating cells. We were not able to show any difference in survival with a mean follow-up of 10.3 years between patients with high and low microvessel count or cell proliferation index. Vascular density did not correlate with the cell proliferation rate (p = 0.4). However, patient age correlated negatively with the cell proliferation index of the tumor (p = 0.0009). There was no significant difference both in microvessel count and in cell proliferation between patients with lymph node metastasis and node negative patients. This result questions the usefulness of vascular density and cell proliferation rate as prognostic markers in breast cancer.

The methodology of quantitation of microvessel density and prognostic value of neovascularization associated with long-term survival in Japanese patients with breast cancer

The present study updates results on methodology of quantitation of tumor neovascularization and those on the prognostic value of microvessel density (MVD) in breast cancer tissue previously published in the World J. Surg. 21: 49-56, 1997. The follow-up period of observation of the series was extended to 20 years, and new biological indicators (i.e., proliferating cell nuclear antigen (PCNA), c-erbB-2, and p53) were included in the analysis. There were 109 patients with primary breast cancer, from 1971 to 1979, followed up for a median of 14 years (range, 1-20). A representative median longitudinal section of each breast tumor was immunohistochemically stained with factor VIII-related antigen and analyzed. The three methods of identifying MVD were: (1) average microvessel count (AMC)/mm2, (2) central microvessel count (CMC)/mm2, and (3) highest microvessel count (HMC)/mm2. Thirty-one patients (28.4%) died of breast cancer. There was a relationship between MVD and peritumor blood vessel invasion (AMC: p = 0.0114, CMC: p = 0.0319, and HMC: p = 0.0009). However, there was no relationship between MVD and other factors. Univariate analysis showed that node status (p < 0.0001), histological grade (p < 0.0001), clinical tumor size (T) (p = 0.0002), PCNA (p = 0.0033), p53 (p = 0.0043), mitotic grade (p = 0.0092), AMC (p = 0.0214), and peritumor lymphatic vessel invasion (p = 0.0467) were significantly predictive of overall survival. HMC was borderline significant (p = 0.0702), while CMC and c-erbB-2 were not significant. Multivariate analysis showed that T (p = 0.0005), node status (p = 0.0053), and AMC (p = 0.0485) were independent factors, but neither CMC nor HMC was independent. AMC, a significant independent prognostic factor, might be a better method than the others for evaluating angiogenesis, but further and larger studies are warranted.

Assessment of vascularity in histological sections: effects of methodology and value as an index of angiogenesis in breast tumours

The aims of this study were to (a) determine how the quantification of blood vessels in histological sections (vascularity) is affected by the methodology used and (b) assess the value of vascularity as an index of angiogenesis by comparing tumour and normal breast tissue. Archival specimens of breast, lung and oral carcinoma, oral dysplasia and normal breast tissue were used to test the effects of the following experimental variables on vascularity: pretreatment of the sections (enzymatic digestion, heating), endothelial markers (von Willebrand factor and CD31 antibodies), method of quantification (highest microvascular density, average microvascular density and microvascular volume) and interobserver variations. All the variables examined significantly affected the estimated vascularity; this depended on the type of tissue and method used. The pretreatment of the sections before staining was the most important variable, altering the vascularity ranking of the tumours. Vascularity in breast tumours was similar to that of the normal breast intralobular stroma, suggesting that an area of high microvascular density in the tumour does not necessarily represent tumour-induced angiogenesis. Contradictory results have been published regarding the value of vascularity as a tumour prognostic factor. Our results suggest that statistically significant differences in vascularity values are most likely to arise from failure to optimize the staining protocol and from the method used to assess vascularity.

Neo-angiogenesis in locally advanced squamous cell head and neck cancer correlates with thymidine phosphorylase expression and p53 nuclear oncoprotein accumulation

Thymidine phosphorylase (Th.P) is an angiogenic factor shown to induce endothelial cell migration and proliferation. On the other hand, loss of wild type p53 function leads to down-regulation of thrombospondin-1, an inhibitor of angiogenesis. In this immunohistochemical study we investigated the intratumoural angiogenesis and thymidine phosphorylase (Th.P) expression in paraffin-embedded bioptical material from 104 locally advanced squamous cell head and neck cancers. The nuclear accumulation of mutant p53 protein and the cytoplasmic expression of bcl-2 protein was also assessed. High vascular grade was observed in 56% and high Th.P tumour cell reactivity in 48% of cases. High microvessel score was associated with an increased percentage of cancer cells expressing thymidine phosphorylase (P = 0.001). Increased p53 nuclear accumulation also correlated with high vascular grade (P = 0.001). High histological grade and absence of bcl-2 overexpression were associated with lymph node involvement (P = 0.002 and P = 0.02 respectively). No correlation of clinically detected lymphadenopathy with angiogenesis and p53 was observed. We conclude that intense neo-angiogenesis in locally advanced squamous cell head neck cancer is a frequent event, which is associated with nuclear p53 accumulation and thymidine phosphorylase overexpression.

Tumour hypoxia and vascular density as predictors of metastasis in squamous cell carcinoma of the uterine cervix

Some clinical studies involving several histological types of cancer have suggested that high vascular density in the primary tumour promotes metastasis. Other studies have suggested that a high incidence of metastases is associated with low oxygen tension in the primary tumour. The purpose of the study reported here was to search for correlations between incidence of metastases and oxygen tension or vascular density in the same population of patients. Thirty-eight consecutive patients with squamous cell carcinoma of the uterine cervix were included in a prospective study. Pelvic, iliac and retroperitoneal lymph node metastases were detected by magnetic resonance imaging at the time of initial diagnosis. Oxygen tension was measured polarographically using the Eppendorf pO2 Histograph 6650. Vascular density was determined by histological examination of tumour biopsies. The primary tumours of the patients with metastases (n = 19) were more poorly oxygenated than those of the patients without metastases (n = 19). Thus, the fractions of the pO2 readings resulting in values below 5 mmHg and 10 mmHg were significantly higher for the former group of patients than for the latter (P = 0.03 and 0.02 respectively). In contrast, the vascular density of the primary tumour was not significantly different for the two groups of patients. The present study suggests that a high incidence of metastases in squamous cell carcinoma of the uterine cervix is associated with poor oxygenation of the primary tumour and not with a high vascular density.

Intratumoral microvessel density and expression of ED-A/ED-B sequences of fibronectin in breast carcinoma

The aim of this study was to examine the correlation between intratumoral microvessel density (iMVD) and the presence of cellular fibronectin isoforms, ED-A and ED-B, in order to identify those tumours with a prominent angiogenic phenotype. 91 cases of invasive ductal breast carcinoma were evaluated for TNM, histological grading, percentage of Ki-67+ cells and receptor hormonal status. iMVD was determined as a single microvessel count in a 200 x microscope field from the region of the tumour that appeared to be most densely vascular. When the mean values of iMVD of the various groups were compared, no significant difference was noted (Mann-Whitney test). When tumours were classified as high or low iMVD, based on a cut-off value (99 vessels/0.74 mm2), cases with high iMVD were significantly more numerous in poorly differentiated G3 tumours (P = 0.01, Chi-square test), and in tumours with lymph node metastasis (N0 versus N1 + N2; P = 0.002). The possibility that high iMVD was the expression of prominent vascular neoformation was explored using ED-A and ED-B isoforms of fibronectin as markers of neoformed vessels. ED-A + and/or ED-B + blood vessels were < 10% of total vessels, were detected in approximately 50% of cases independently of iMVD values, and were not more numerous in tumour areas with hot spot vascularisation. Our findings indicate that iMVD and expression of ED-A/ED-B reflect different aspects of tumour-associated angiogenesis.

Tumor angiogenesis as a prognostic marker in operable non-small cell lung cancer

BACKGROUND

Recent evidence suggests that tumor angiogenesis is associated with patient outcome in a number of malignancies. However, little is known about the significance of tumor microvessel density as evaluated by an anti-CD34 antibody in patients with lung cancer.

METHODS

Tumor tissues were obtained from 101 patients with operable non-small cell lung cancers. Immunohistochemical detection of tumor-associated microvessels was performed using anti-CD34 antibodies directed against endothelial markers. Average counts of the three most vascular areas on a X200 field were recorded.

RESULTS

Staining for CD34 was easy to interpret because of specific and minimal background staining. The Kaplan-Meier method showed a statistically significant difference between the microvessel count and overall survival. The microvessel count was identified as the only significant and independent prognostic marker. In both univariate and multivariate analyses, the microvessel count was significantly related to the development of hematogenous metastasis but failed to associate with the development of nodal metastasis.

CONCLUSIONS

Tumor vascularity is an independent prognostic factor and important for the development of hematogenous metastasis.

The microcirculation of choroidal and ciliary body melanomas

The microcirculation of ciliary body and choroidal melanomas is remodelled into patterns. The presence of microvascular networks, composed of back-to-back loops that encircle microdomains of tumour, and parallel vessels with cross-linking, are associated with death from metastatic melanoma. The formation of these complex vascular patterns may result from reciprocal interactions between the tumour cell and the extracellular matrix, and pattern formation may reflect an invasive tumour cell phenotype. Ciliary body and choroidal melanomas are among the few forms of cancer treated before a pathologist assigns a grade to indicate whether tumour is likely to follow a benign or aggressive course. There is evidence to suggest that prognostically significant microcirculatory patterns may be detectable by non-invasive imaging techniques that may provide a substitute for biopsy to guide the clinical management of patients with these sight- and life-threatening tumours.

An improved procedure to quantify tumour vascularity using true colour image analysis. Comparison with the manual hot-spot procedure in a human melanoma xenograft model

In a number of recent papers, the degree of tumour vascularization has been described as a promising new prognostic factor. Methods for the assessment of vascular density involve immunohistochemical staining of the vasculature, followed by counting the number of vessel profiles in the angiogenic hot spot. One of the problems of this procedure is the selection of the angiogenic hot spot, which has been described as being subject to inter-observer variation. In this study, the value of true colour image analysis in reducing inter-observer variation has been assessed. Highly (MV3) and poorly (M14) vascularized human melanoma xenografts were used to evaluate the image analysis procedure, and the image analysis results were compared with results from the conventional manual hot-spot procedure. Assessment by image analysis was performed on measurement fields covering the entire tumour tissue specimens rather than on a single hot-spot field. Also, by selecting the most densely vascularized area from all fields assessed by the semi-automatic procedure, it was possible to objectify the hot spot selection (automated hot-spot procedure). Manual assessment showed a good correlation between two independent observers for MV3 xenografts (r = 0.74, P = 0.014), but a poor correlation for M14 xenographs (r = 0.4, P > 0.05). Automated assessment by different operators showed good correlations for both MV3 xenografts (r = 0.99, P < 0.001) and M14 xenografts (r = 0.80, P = 0.006). It is concluded that although both manual vessel counting and semi-automated image analysis can differentiate between the level of vascularization in the two types of xenograft (P < 0.001 for both methods), the automated method is favourable in that it showed no significant inter-observer effects. In M14 xenografts, the manual hot-spot vessel densities did not correlate well with the automated hot-spot densities (r = 0.27, P > 0.05), indicating that selection of angiogenic hot spots in this tumour type is indeed subject to observer bias. The automated hot-spot vessel densities were a reliable indicator of overall tumour vessel density in both tumour types. Image analysis allows analysis of vessel subclasses based on morphological criteria such as vessel profile area or diameter. In the model system used, the discrimination between MV3 and M14 xenografts was further enhanced by selectively examining vessels with diameters between 6 and 9 microns (P < 0.0005). In conclusion, image analysis appears to offer an objective and more reproducible method to quantify tumour vascularity than manual counting of vessel profiles in the hot spot. Analysis of subclasses of vessels may further enhance the value of vessel density measurements in discriminating between tumour types differing in biological behaviour.

Tumor angiogenesis, hepatocyte growth factor, and c-Met expression in endometrial carcinoma

BACKGROUND

This study was designed to evaluate the significance of tumor angiogenesis and angiogenic factors such as hepatocyte growth factor (HGF) and c-Met in determining the prognoses of 93 patients with endometrial carcinoma.

METHODS

By immunohistochemical staining, this retrospective study investigated tumor angiogenesis, HGF expression, and c-Met expression, using one tissue slide that was representative of the invasive edge of the tumor. To evaluate tumor angiogenesis, the microvessels within the primary endometrial carcinoma were highlighted by staining their endothelial cells immunohistochemically for von Willebrand factor (VWF). The microvessels were then counted in the most intense areas of neovascularization. HGF and c-Met were identified with specific antibodies. Tumor angiogenesis, HGF expression, and c-Met expression were correlated with both the prognostic variables for and the survival of endometrial carcinoma.

RESULTS

A high microvessel count (> or = 110 in a 0.90 mm2 area) was significantly correlated with surgical Stage III and IV, histologic Grade 3, positive lymph node involvement, and shorter patient survival. Expression of c-Met was significantly correlated with surgical Stage III and IV, histologic Grade 3, and shorter survival. HGF expression was significantly correlated with surgical Stage III and IV by semiquantitative analysis. Multivariate analysis showed that surgical Stage III and IV, histologic Grade 3, the score for myometrial invasion > 1/2, and a high microvessel count were independent indicators of the prognoses of patients with endometrial carcinoma.

CONCLUSIONS

Both tumor angiogenesis, measured by the microvessel count, and c-Met expression were significant prognostic indicators for patients with endometrial carcinoma.

Angiogenesis as a prognostic marker in breast carcinoma with conventional adjuvant chemotherapy: a multiparametric and immunohistochemical analysis

It has now been clearly established that quantitative immunohistochemical methods applied to tumour angiogenesis under suitable quality control conditions are a powerful prognostic tool for use in the initial assessment of breast carcinomas. Appropriate parameters for predicting the aggressiveness of tumours and their sensitivity to treatment are, however, still required. To determine whether the microvessel count (MVC) may serve to predict the chemotherapeutic response, a retrospective study was carried out on a series of 162 patients with breast carcinoma, who were all treated with the same standard adjuvant chemotherapy. Angiogenesis was assessed by performing CD31 immunostaining and MVC per mm2. Several other factors such as P53, ERBB2, BCL2, and Ki67 were also measured, and their prognostic value was compared with that of the MVC. The MVC was not found to be correlated with any of the other prognostic parameters, but turned out to be of great prognostic value whatever the threshold value chosen, which suggests that it is continuously valid at all levels. The median value of the MVC (43.5 per mm2) divided this series into two significantly different prognostic categories, in terms of both disease-free survival (P = 0.0002) and overall survival (P = 0.037). Univariate analysis showed that most of the parameters analysed were of prognostic value regarding the disease-free survival, namely grade (P = 0.029), mitotic index (P = 0.049), size (P = 0.015), oestrogen receptors (P = 0.022), progesterone receptors (P = 0.018), P53 (P = 0.0045), ERBB2 (P = 0.046), and Ki67 (P = 0.0008). As regards overall survival, grade and ERBB2 showed a loss of prognostic value. In multivariate analysis on disease-free survival, the MVC was the most accurate prognostic factor (RR = 2.64), followed by Ki67 (RR = 2.06) and P53 (RR = 1.69). With respect to overall survival, the MVC ranked third among the prognostic parameters analysed. Standard chemotherapy did not reduce the high prognostic value of the MVC performed on tumour angiogenesis. This suggests that the MVC may predict the degree of resistance to chemotherapy. Patients with high levels of angiogenesis, particularly node-negative patients, might therefore be able to benefit from adjuvant therapy of another kind.

Vessel counts and vascular endothelial growth factor expression in pancreatic adenocarcinoma

Angiogenesis is essential for growth and metastasis of solid malignancies. In several tumours, tumour vessel count and expression of vascular endothelial growth factor (VEGF), a potent angiogenic factor, have been associated with prognosis. To determine if vessel count and VEGF expression are prognostic factors in pancreatic cancer, we examined these parameters in resected tumour specimens from 22 patients who did not receive pre-operative therapy. Paraffin-embedded tumour specimens were immunohistochemically stained for factor VIII (surrogate for vessels) and VEGF. Vessel counts and VEGF expression were evaluated without knowledge of patient outcome. The median follow-up for the entire group had not been reached as of 23.1 months (range 10-69 months). The mean vessel count and VEGF expression were no different between those patients who had recurrences and those who did not. By linear regression analysis, the correlation of VEGF expression with vessel count did not reach statistical significance (P = 0.0685). Survival and time to recurrence were similar in patients with high and low vessel counts and VEGF expression of 1, 2 or 3. Tumour differentiation or lymph node positivity had no effect on either VEGF expression or vessel count. Our data suggest that, in contrast to findings in other solid malignancies, vessel count and VEGF expression are not predictors of survival or recurrence in patients with resectable adenocarcinoma of the pancreas.

Angiogenesis in hepatocellular carcinoma as evaluated by CD34 immunohistochemistry

To clarify the relationship between angiogenesis and hepatocarcinogenesis on progression of hepatocellular carcinoma (HCC), we quantitatively evaluated angiogenesis by CD34 immunohistochemistry in liver cirrhosis (LC), adenomatous hyperplasia (AH), and HCC, and proliferative activity estimated by Ki-67 immunohistochemistry. Angiogenesis was evaluated by CD34 immunohistochemistry using monoclonal antibody HPCA-2, and tumor proliferative activity was evaluated using monoclonal antibody MIB-1. We used an image analysis system to assess the microvessel density as the area percentage of the endothelial area. Angiogenesis was generally observed in HCC and there was no significant difference among all clinical stages and histological grades of HCC. On the other hand, the staining of CD34 was partly observed in sinusoids of AH, although no positive staining was seen in any sinusoids of LC. The proliferative activity was significantly correlated with the clinical stage and histological grade of HCC. Our results indicate that the quantitation of angiogenesis does not provide significant prognostic information in HCC, but that it may have diagnostic value in distinguishing HCC from non-HCC. Meanwhile, AH, which is not morphologically diagnosed as cancer, shows positive staining for CD34, suggesting that some portion of AH contains cancerous characteristics.

Expression of Tie2/Tek in breast tumour vasculature provides a new marker for evaluation of tumour angiogenesis

Endothelial receptor tyrosine kinases may play important roles in pathological vascular growth, particularly in tumours. In this study, immunohistochemistry was used to evaluate the expression of a novel endothelial receptor tyrosine kinase, Tie2/Tek, in the endothelium of vascular 'hotspots' in normal breast tissue (n = 10), benign breast lesions (n = 10) and in breast tumours (n = 123). Tie2 expression was detected in the endothelium of all breast tissues examined. However, the strongest expression of Tie-2 was seen in vascular 'hot spots' within the inflammatory infiltrate at the periphery of invasive tumours. Moreover, the proportion of Tie2-positive vessels (Tie2 counts/CD31 counts) was significantly higher in breast tumours than the proportion of Tie2-positive vessels in either normal breast tissue or benign breast lesions (P = 0.004 and 0.0001 respectively). These data are consistent with a role for Tie2 in tumour angiogenesis and demonstrate the potential use of Tie2 expression as a novel marker of the tumour vasculature.

Neovascularity and clinical outcome in high-grade extremity soft tissue sarcomas

BACKGROUND

Increased tumor neovascularity has been shown to correlate with poor prognosis in solid tumors.

METHODS

Microvessels were identified by factor VIII immunohistochemical staining. Analysis of microvessel counts, tumor characteristics, and resection details was performed on 119 primary, high-grade extremity soft tissue sarcomas (STS) and correlated with clinical outcome.

RESULTS

Tumor characteristics and resection details were analyzed and patient outcome was examined with respect to local recurrence, distant metastasis, and disease-specific survival. Factors found to be significant on univariate analysis for all outcome variables were positive microscopic margin and tumor size. A positive microscopic margin was found to be a significant risk factor for local recurrence (P = .03), distant metastasis (P = .006), and disease-specific survival (P = .004). A primary tumor greater than 10 cm in diameter was a poor prognostic factor for distant metastasis (P = .03) and disease-specific survival (P = .006) when compared to tumors smaller than 10 cm. Microvessel count did not correlate with survival nor did it predict distant metastasis or local recurrence. Histologic subtypes of STS that have a prominent vascular pattern as a diagnostic criterion (i.e., angiosarcoma, liposarcoma, hemangiopericytoma) form a subgroup of all STS. Neovascularity in these subtypes showed no relationship to clinical outcome.

CONCLUSIONS

These data confirm the prognostic importance of microscopic margin and tumor size in high-grade extremity STS. Neovascularity measured by factor VIII staining had no prognostic significance in these mesenchymal tumors, in contradistinction to carcinomas. Alternatively, microvessel counts may not accurately represent the angiogenic capacity of STS. Therefore, patients with STS who are eligible for anti-angiogenesis clinical trials cannot be identified solely by microvessel count.

Assessment of vascularity in breast carcinoma by computer-assisted video analysis (CAVA) and its association with axillary lymph node status

Case-control methodology was used to evaluate the significance of vascularity in small breast carcinomas with regard to the presence or absence of axillary lymph node metastases. Vascularity was assessed in 32 axillary node positive primary breast tumours (LN+ve) less than 2 cm in size and compared with 56 control axillary node negative primary tumours (LN-ve), which were matched for histological type and grade and tumour size. This study design employed computer-assisted video analysis (CAVA) to assess the total blood vessel perimeter (BVP), total blood vessel area (BVA), and total blood vessel density (BVD) throughout a tissue section that encompassed an entire cross section of the tumour and its immediate periphery. The BVA and BVD in these tumours were not significantly different between LN+ve and LN-ve groups. The LN-ve carcinomas had, on average, a significantly (P<0.05) higher total BVP (3355 microm/mm2) than LN+ve tumours (2771 microm/mm2). 'Hot spot' areas were also independently assessed by two pathologists and the same areas measured by CAVA. A strong correlation (P<0.001) between the two methods of assessment of BVD of the neovascular 'hot spots' was found; however, no association with axillary lymph node metastasis was found using either method of assessment. In conclusion, vascularity assessed by either blood vessel density or blood vessel size in primary invasive breast cancers less than 2 cm in diameter showed no association with axillary lymph node metastasis; in fact a negative association was found with total BVP of whole tumour sections and BVD in 'hot spots' using CAVA. Further, this study has established a computer-assisted method of quantifying vascularity in solid neoplasms and is a positive step towards a standardised approach to this diverse and methodologically variable area.

Microvessel density, p53 overexpression, and apoptosis in invasive breast carcinoma

AIM

To investigate the possibility of a correlation among microvessel density, p53 overexpression, and apoptosis in invasive breast carcinoma.

METHODS

Microvessel density was analysed in 105 cases of invasive breast carcinoma by immunohistology using antifactor VIII related antibody. The results were correlated with the immunohistochemical expression of p53 and the apoptotic index, detected using the in situ end labelling of fragmented DNA method (TUNEL). Assessment was made with a CAS 200 image analyser. All these studies were performed on formalin fixed, paraffin wax embedded tissue sections of tumour samples.

RESULTS

The mean (SD) microvessel count was 47.2 (51.1), with a range from 7 to 250. Thirty five (33%) carcinomas showed overexpression of p53 protein. The apoptotic index of tumours ranged from 0.0 to 28.0, with a mean (SD) of 1.7 (3.2). The results showed that there was a significant inverse correlation between microvessel density and p53 expression (p = 0.04; odds ratio, 0.37). In contrast, no correlation was identified between the microvessel density and apoptotic index.

CONCLUSIONS

These results suggest that in invasive breast carcinoma the p53 overexpression phenotype downregulates tumour neoangiogenesis, as does the wild-type of p53 protein. In addition, they suggest that apoptosis and neoangiogenesis in these tumours are independent processes.

Association of vascular endothelial growth factor expression with tumor angiogenesis, survival and thymidine phosphorylase/platelet-derived endothelial cell growth factor expression in human colorectal cancer

To examine the association of vascular endothelial growth factor (VEGF) expression with tumor angiogenesis, survival and thymidine phosphorylase/platelet-derived endothelial cell growth factor (dThdPase/PD-ECGF) expression in human colorectal cancer, immunohistochemical studies were performed on 136 cases of resected colorectal cancer specimens using antibodies for VEGF, KDR, CD34 and dThdPase/PD-ECGF. Fifty-nine cases (43%) were evaluated as positive for VEGF staining and 71 cases (52%) were evaluated as positive for dThdPase/PD-ECGF staining. The expression of VEGF correlated significantly with vessel counts and the expression of dThdPase/PD-ECGF (P = 0.01 and 0.01, respectively). Cox proportional hazards model analysis showed that vessel counts and VEGF expression were significant and independent prognostic factors, but that KDR expression was not.

Differences in tumor microvessel density between squamous cell carcinomas and basal cell carcinomas may relate to their different biologic behavior

Tumor microvessel density (TMVD) has been recognized as an important indicator for the metastatic risk in certain tumors. The purpose of this study was to analyse whether there is an association of TMVD in epithelial neoplasms of the skin with their clinical behavior. Paraffin sections of keratoacanthomas (KA, n = 10), squamous cell carcinomas (SCC, n = 9), nodular (nod-BCC, n = 13), and sclerosing (scl-BCC, n = 12) basal cell carcinomas were immunohistochemically stained for factor-VIII-related antigen and TMVD was determined. In all SCC, KA and nod-BCC, TMVD significantly exceeded perilesional skin microvessel density (PSMVD) (SCC:TMVD/PSMVD = 20.54:11.25, p < 0.0001; KA:TMVD/PSMVD = 20.90:12.17, p < 0.0001; nod-BCC:TMVD/PSMVD = 16.77:13.34, p = 0.03). In contrast, no significant difference between TMVD and PSMVD was found in scl-BCC (15.44:12.86, p = 0.22). TMVD was significantly higher in SCC and KA compared to nod-BCC (p = 0.036 and 0.006, respectively). Our data demonstrate that SCC and KA are highly vascularized tumors. The fact that TMVD does not differ significantly between SCC and KA (p = 0.80) suggests that MVD is not an indicator for the metastatic risk or aggressive growth behavior of epithelial skin tumors. The finding that MVD in both nod- and scl-BCC is significantly lower than in SCC and KA, might at least in part explain the slow growth of BCC.

Evaluation of tumour angiogenesis as a prognostic marker in malignant mesothelioma

Angiogenesis plays an important role in the growth, progression, and metastasis of solid tumours. Malignant mesothelioma (MM) of the pleura is a highly invasive tumour with a poor prognosis. In the present study, microvascular quantification was undertaken on 25 specimens of mesothelioma and 15 specimens of non-neoplastic mesothelium (NNM), by staining for the antigens CD34 and CD31. Areas of highest intratumoural microvascular density (IMD) were identified and counted either manually (mIMD) or on a computerized image analysis system (CIAS; iIMD). The two IMDs were significantly correlated with each other (r = 0.736; P < 0.001). The average IMD for MM was significantly (P < 0.001) higher than in NNM. Moreover, each unit increment in iIMD for MM, when regarded as a continuous variable, was significantly (P = 0.001) associated with an increased hazard of about 4 per cent. When regarded as a categorical variable, the patients in the highest tertile (> 58 vessels/field) had a significantly (P < 0.01; log-rank test) shorter survival than patients in the lowest tertile (< 45 vessels/field). This association was independent of the age of the patient and of the histological type or grade of the MM. No association was noted with p53 immunoexpression. Although the mean vascular area of blood vessels measured on the CIAS did not correlate with survival, assessment of IMDs can be an important independent prognostic indicator in malignant mesothelioma.

Relative importance of quantifying area and vascular patterns in uveal melanomas

PURPOSE

To test whether the cross-sectional area of choroidal and ciliary body melanomas and quantification of microcirculatory networks and parallel vessels with cross-linking are features associated with death from metastatic melanoma, and to compare new with conventional histologic prognostic features.

METHODS

The cross-sectional area of 234 ciliary body or choroidal melanomas was measured from digitized images of histologic sections. The percentage of cross-sectional area occupied by two microcirculatory patterns-networks and parallel vessels with cross-linking-was calculated for the 152 tumors containing at least one focus of either pattern. Kaplan-Meier survival curves were generated based on cross-sectional and percentage of cross-sectional areas of these patterns. Cox proportional hazard regression methods related time to death from melanoma with sets of predictor variables. For each model, percent variation explained was computed.

RESULTS

Patient survival differs significantly when tumors are classified based on cross-sectional area: small (<16 mm2), medium (> or =16 mm2 but <61.4 mm2), and large (> or =61.4 mm2). Patients with tumors containing networks and parallel vessels with cross-linking microcirculation patterns that occupy 2% of cross-sectional area have a significantly worse prognosis than do those patients with tumors containing a smaller percentage of these patterns.

CONCLUSIONS

Quantifying cross-sectional tumor area and the percentage area occupied by networks and parallel vessels with cross-linking microcirculatory patterns in ciliary body and cho. roidal melanomas provides significant prognostic information. Compared with more conventional prognostic characteristics, the most dramatic increase in prognostic information is provided by determination of the presence or absence of microvascular patterns.

Influence of investigator experience and microscopic field size on microvessel density in node-negative breast carcinoma

In this study on the determination of intratumoral microvessel density (MVD) in breast cancer, we have investigated the influence of the observer experience and the microscopic field size. We have used the sample set reported on earlier in the J Natl Cancer Inst 87: 1797-1798, 1995. This case-control study has shown a positive association of high MVD and unfavorable outcome when comparing node-negative pT1-2 breast carcinoma (NNBC) patients with a disease-free period of over ten years with those with an early distant relapse. Tumor sections of both outcome groups (favorable: n = 19; unfavorable: n = 19) were immunostained for factor VIII related-antigen (FVIII r-Ag). Microvessels were counted in the areas of most intense vascularization ('hot spots'), both at magnification x 200 (field size of 0.61 square mm) and x 400 (field size of 0.15 square mm), by one inexperienced and three experienced observers. Microphotographs of individual vascular hot spots were analyzed using overlays resembling the two field sizes. The main results obtained are: i) a confirmation of the prognostic value of microvessel density in the case-control sample set (n = 38) was established by all experienced but not by the unexperienced investigator; ii) both at x 200 and x 400 magnification, angiogenesis quantification in vascular hot spots contained prognostic information. The results of this study indicate that the selection of vascular hot spots in tumor sections immunostained for an antigen expressed on endothelial cells is more prone to inter-observer variability and more dependent on training than the counting of the microvessels within predefined hot spots itself. The microscopic magnification and resulting field size do not influence the prognostic significance of MVD in NNBC. This information validates the development of more objective methods of measuring the amount of angiogenesis within malignant tissue. This will allow more accurate implementation of the angiogenesis parameter in multiparametric and prospective prognostic factor studies in NNBC.

Examining the technique of angiogenesis assessment in invasive breast cancer

The intensity of angiogenesis as measured by the density of microvessels has been reported to be associated with a poor prognosis in invasive breast cancer in some, but not all, studies. The reasons for these discrepancies may be variations in the methodologies used. The monoclonal antibody used to identify the microvessels, the number of high-density areas or 'hotspots' counted and the type of value taken for statistical analysis (highest count or mean count) have varied between the different studies. We have assessed which of the three commonly used monoclonal antibodies provides the best visualization of microvessels in invasive breast cancer and have used methods that give reproducible data for the optimum number of 'hotspots' to count for each reagent. Thus, microvessels in formalin-fixed paraffin-embedded specimens from 174 primary breast cancers were immunohistochemically stained with monoclonal antibodies to FVIIIRAg, CD31 and CD34 and ten fields counted at 200 x magnification for each antibody. The highest count and the mean value of the highest of three, five and ten counts were used to examine the relationship between the density of microvessels and overall survival of patients with a median follow-up time of 7.1 years. Antibodies to CD31 and CD34 identified more vessels than antibodies to FVIIIRAg (median highest count per mm2: CD31 = 100, CD34 = 100, FVIIIRAg = 81). The monoclonal antibody to CD31, however, was the least reliable antibody, immunohistochemically staining only 87% of sections compared with 98% for the monoclonal to CD34 and 99% for the monoclonal to FVIIIRAg. There was a high degree of correlation between the number of vessels stained by the different antibodies, though there were some considerable differences in actual counts for serial sections of the same specimen stained by the different antibodies. Patients could be divided into two groups corresponding to those with high microvessel densities and those with low microvessel densities. Using Kaplan-Meier survival curves, there was a close association for all three antibodies between vessel density and survival whichever method of recording the highest vessel densities was used. Using log-rank tests and Cox's regression analysis, anti-CD34 gave the most significant results of the three antibodies, whereas a simple cut-off at the 75th percentile for the high and low groups produced the best association with patient survival. For anti-CD34 the highest microvessel density (P = 0.0014) and the mean value of the highest three microvessel densities (P = 0.004) showed a good correlation with patient death, whereas for anti-CD31 (P = 0.008) and anti-FVIIIRAg (P = 0.007) the highest count gave the best correlation using Cox's regression analysis.

Tumour angiogenesis as a prognostic marker in infiltrating lobular carcinoma of the breast

The importance of angiogenesis, assessed by tumour microvessel density, as a marker of survival was examined in 160 patients with infiltrating lobular carcinoma of the breast (ILC). The median follow-up was 5.1 years. Of these patients, 46 were node-negative, 59 were node-positive, and in 55 the pathological lymph node status was not known. Tumour sections were immunohistochemically stained with Factor VIII-related antibody. Microvessels were identified using previously recommended methodology and counted in three separate fields, selected from areas of highest vascularity, at x 200 magnification (field area = 0.785 mm2). Only the highest count was considered in the analysis. No association was found between microvessel density and age, menopausal status, tumour size, histological subtype, peritumoural vessel invasion, and lymph node involvement at presentation. There was no association between microvessel density and overall survival or relapse-free survival. These results suggest that microvessel density assessment, using currently recommended methods, is unlikely to be of prognostic value in ILC.

Vascularity demonstrated by Doppler ultrasound and immunohistochemistry in invasive ductal carcinoma of the breast

BACKGROUND

Vascularity is an important determinant of a tumour's ability to grow and disseminate. Breast tumour vascularity can be determined with doppler ultrasound (US) and by counting the vessels microscopically (microvascular density-MVD). The biologic characteristics of tumours based on their vascularity have not been extensively studied.

METHOD

Preoperative US was performed on 207 patients with invasive ductal breast carcinomas (IDC). MVD was assessed immunohistochemically using polyclonal antisera against factor VIII and the proliferation rate was measured with Ki-67 polyclonal antisera. Histologic tumour characteristics and oestrogen receptor (ER) status were determined. Thermography was performed on 174 of the patients.

RESULTS

Twenty-five percent of IDC demonstrated US-vascularity. US-vascular tumours were more likely to be node positive, and had a higher mitotic rate than avascular cancers. US-vascularity was more common in tumours with MVD greater than 80 vessels/250x field than those with fewer vessels. The proliferation rate, histologic grade III, and nuclear grade III were higher and ER positivity lower, but the differences were not statistically significant. US-vascular cancers were associated with significantly more thermographic abnormalities. The cancer recurrence rate at three years was higher in patients with vascular cancers although the difference was not statistically significant.

CONCLUSION

US appears to be a simple, non-invasive method of identifying vascular cancers associated with factors indicating a poor prognosis.

Endothelial area as a prognostic indicator for invasive breast carcinoma

BACKGROUND

Vascular enumeration using antibodies to Factor VIII has been reported to be an independent prognostic indicator of invasive breast carcinoma.

METHODS

To eliminate potential subjectivity in distinguishing between individual vessels, especially in areas of tangled capillaries, total endothelial area (EA) was assessed using a Samba 4000 image analyzer. One hundred seventy-eight invasive breast carcinomas (Stage 1 and 2, mean follow-up: 71 months) were immumostained for the presence of CD34, the human hematopoietic progenitor cell antigen also present in endothelium, and EA was quantitated within 5 adjacent 20X fields (0.74 mm2). Additionally, these same vessels were manually counted from the image analyzer. Manual counts were also made from a photomicrograph representative of a single 10X field (1.06 mm2).

RESULTS

High grade carcinomas contained greater endothelial area than low grade carcinomas (P = 0.0001). Endothelial area was prognostically significant (P = 0.004) in univariate analysis of disease-free survival (DFS) and overall survival (OS), as were stage of disease, tumor size, and combined histologic grade (P < or = 0.024). Manual vessel counts from the monitor were significant for OS only. Manual vessel counts from photomicrographs showed no statistically significant association with DFS or OS. In multivariate analysis, EA, but not vessel enumeration, remained as an independent predictor for OS (lymph node negative patients only, n = 87) and for DFS (lymph node positive patients only, n = 91). For the entire group of patients (lymph node negative and lymph node positive) independent predictors of DFS and OS were tumor grade and size (P < or = 0.006).

CONCLUSIONS

Of the three methods used to evaluate tumor angiogenesis, total endothelial area, as objectively evaluated by image analysis, was the only independent prognostic indicator for OS for patients with lymph node negative invasive breast carcinoma.