Cell proliferation and vascularization in human breast carcinomas

The Prognostic Value of p53 and c-erbB-2 Expression, Proliferative Activity and Angiogenesis in Node-Negative Breast Carcinoma

Aims and background

p53, c-erbB-2 and Ki-67 protein expression and microvessel density (MVD) determined by CD34 antibody were evaluated by immunohistochemistry and their correlation with clinicopathological parameters including estrogen (ER) and progesterone (PR) receptor status and survival were investigated in patients with axillary lymph node-negative infiltrating ductal breast carcinoma.

Methods

The study population consisted of 47 patients with axillary lymph node-negative infiltrating ductal breast carcinoma.

Results

p53 and c-erbB-2 expression was detected in 36.2% and 31.9% of patients, respectively. Median Ki-67 expression was 10%. There were no statistically significant differences in the distribution of p53, Ki-67 and c-erbB-2 protein expression in relation to the age of the patients or to the size, histological grade or ER and PR status of the tumors. p53 protein expression correlated positively with c-erbB-2 and Ki-67 protein expression (P <0.05). The mean MVD was 63.65 ± 29.1 and it correlated positively with histological grade and Ki-67 expression (P <0.05). Survival analysis revealed that age, tumor size, p53 and c-erbB-2 expression and PR status had no significant prognostic impact, whereas histological grade, proliferative activity and angiogenic activity were significant prognostic factors. Although ER-positive patients had a statistically significant overall survival advantage, the difference in disease-free survival was not significant.

Conclusion

In axillary lymph node-negative breast carcinoma the histological grade and the proliferative and angiogenic activity of the tumor could be useful prognostic indicators.

The vascular network of tumours--what is it not for?

It is becoming almost a dogma that tumours cannot grow beyond 1-2 mm(3) unless they are supported by a rich vascular supply 1. It is true that tumours promote angiogenesis and that highly vascularized carcinomas have, in general, a more aggressive clinical course than carcinomas of low vascularization 23. However, a study of intratumoral angiogenesis reveals that the newly formed vessels are commonly deprived of those structural qualities that would allow them to perform an optimal oxygenation function 3. Thus, most tumours, irrespective of their angiogenic status, behave as if they were 'hypoxic', urging (via angiogenic mediators) for, what would look paradoxical at first sight, more defective angiogenesis. It is hypothesized that tumour cells can grow into solid neoplasms by exploiting the host's pre-existing vessels, without the need for new blood vessel formation. Neovascularization, however, may be important for tumours with an exophytic pattern of growth as these, by their very nature, lose the host's sheltering stroma. Shifting to anaerobic glycolysis and activation of anti-apoptotic pathways are complementary mechanisms for tumour cell survival and growth. Besides, continuous and indiscriminate production of a defective vascular network ensures an increased metastatic potential since the newly formed intratumoral vessels, simulating venular-like spaces, are easily permeable to tumour cells, facilitating metastases.

Radial intratumoral increase and correlation of microvessels and proliferation in solid breast carcinoma

AIMS

To compare correlations between different morphometrically assessed measurements of tumour microvasculature and to identify those which show closest correlation with Ki67 and to examine radial intratumoral distribution of microvessels and proliferation.

METHODS AND RESULTS

Immunohistochemically defined microvessels and Ki67+ cells were quantified in sequential fields of 0.12 mm2 (x600) in four transects in each of five tumours. The total number of vessels (TNV) correlated more closely with proliferative activity than the numbers of vessels with a discernible lumen (TLV) and TNV decreased towards the centre of the tumour whereas TLV did not. A higher proliferative index (PI) was found at the periphery of the tumours. Comparison between transects through subjectively identified microvessel hot-spots and non-hot-spot transects showed similar mean, median and peak vessel counts but showed a different distribution on chi2 analysis.

CONCLUSIONS

TNV correlates most closely with PI in breast carcinomas. There is marked variation in microvessel density and PI between fields of 0.12 mm2 but there is a significant radial reduction in both from the edge towards the centre of tumours.

Hot spot microvessel density and the mitotic activity index are strong additional prognostic indicators in invasive breast cancer

AIMS

Recent studies have drawn attention to intratumoral microvessel density (MVD) as a prognostic factor in invasive breast cancer. Various methods have been applied to assess MVD and the prognostic value of MVD in different studies varies considerably. Counting of microvessels in the most highly vascularized area (hot spot) of a tumour is the method most widely used. In this study we compared three counting methods.

METHODS AND RESULTS

To assess MVD in 112 cases of invasive breast cancer with long-term follow-up we performed microvessel counting in the hot spot of the tumour in four and 10 fields of vision (HS-MVD4 and HS-MVD10) and microvessel counting in 10 fields of vision distributed systematically over the whole tumour area (global MVD). The HS-MVD4, HS-MVD10 and global MVD showed good correlations with each other. HS-MVD4 provided the highest number of microvessels (median value 71) followed by HS-MVD10 and global MVD, with median values of 58 and 39, respectively. HS-MVD4 showed the best prognostic value for overall survival (P = 0.0001) whereas HS-MVD10 showed less (P = 0.01) and the global MVD showed no (P = 0.75) prognostic value. In univariate analysis, the HS-MVD4 was the second strongest prognostic factor after tumour size. In multivariate survival analysis, the HS-MVD4, mitotic activity index (MAI), lymph node status and tumour size were found to be independent prognostic factors. When combining MVD4 and MAI in lymph node negative patients, none of the patients with low MVD (< 71/mm2) and a low MAI (< 10 per 10 HPF) died, in contrast to patients with a high MVD or high MAI who have a 10-year survival of 57%.

CONCLUSIONS

These data suggest that the hot spot MVD in four fields of vision is a major independent prognostic factor for overall survival in invasive breast cancer. For the first time, it is shown that hot spot MVD provides additional prognostic information to well established factors like lymph node status and the MAI, and may therefore be useful for designing treatment strategies in invasive breast cancer.

Relationships between vascularization and proliferation in invasive breast cancer

Studies on relationships between angiogenesis and tumour cell proliferation have provided conflicting results. This study has therefore investigated the relationships between the number and location of fully automatically identified CD31-positive microvessels and interactively segmented mitoses and necrotic compartments by image processing. These features were studied in ten invasive breast cancers, in the 'hot spots' and in whole tumour sections. Microvessel and mitosis hot spots were topographically close or overlapping and were always located at the periphery of the tumour. The numbers of mitoses and microvessels per mm(2) in the hot spot were strongly correlated with the respective numbers in the whole tumour section, as well as mutually. The ratio of mitoses in the hot spot to the whole tumour section was significantly higher than the corresponding microvessel ratio. Mitoses were preferentially located at a distance of 50-150 microm from microvessels. No significant difference was found between the average distance between mitoses and microvessels in the whole tumour sections and in the hot spot (79 vs. 72 microm), although considerable inter-tumour differences were found (hot spot 43-101 microm, tumour 47-111 microm). The presence of necrotic areas correlated with the number of mitoses per mm(2) and necrosis was in general observed at a distance of more than 150 microm from the microvessels, suggesting that necrotic areas have outgrown their vascular system. These results indicate the usefulness of image processing of whole tumour sections for the identification of proliferation and vascularization hot spots, which are strong prognostic factors in breast cancer. The results also support a close relationship between tumour necrosis and microvessels.

Tumor oxygenation correlates with molecular growth determinants in breast cancer

Hypoxic tumor cells may represent a fraction of cells that are not susceptible to radiation or chemotherapy. Intratumoral oxygen partial pressure (pO2) is the result of oxygen delivery and consumption. Cell proliferation is one factor to effect oxygen consumption and we therefore studied the correlation between tumor pO2 and histological parameters.

PATIENTS AND METHODS

In 36 women and one man (age range 29-80 years) with suspected breast cancer. Before tumor resection, intralesional pO2 was determined with a polarographic needle electrode. Under ultrasound control, 200 tumor measurements were obtained; Hb levels, Hk, arterial blood gas parameters, and tissue temperature were determined. The median of pO2 values and the percentage of hypoxic areas (pO2 < 10 mmHg) were calculated and correlated with the histological type, grading, ER, PR, and the expression of Ki-67, p53, EGFR, pS2, and c-erb-B2.

RESULTS

The overall median pO2 was 44 mmHg, and 1024 measurements (13.8%) represented hypoxic areas. Ductal and lobular invasive cancers showed median pO2 of 41 mmHg. The mean pO2 of G1 tumors was 59 mmHg and the hypoxic fraction 8%, in contrast to G2 tumors with 43 mmHg and 17%, and G3 tumors with 36 mmHg and 20.4% (p < 0.01). We observed a correlation with tumor size and an increased rate of hypoxic areas in T3-4 lesions (p < 0.02). Also tumors with negative nodes or positive ER had significantly higher pO2 values, as did tumors with an overexpression of c-erb-B2, p53, and cathepsin D.

CONCLUSION

Oxygenation of human breast cancers can safely be measured in patients prior to surgical therapy. pO2 values correlate both with prognostic markers examined histologically and with molecular growth factors. As the efficacy of preoperative or adjuvant treatment in individuals may depend on oxygen partial pressure, efforts to manipulate tumor pO2 for therapeutic purpose could be promising.

Interstitial stroma and carcinogenesis: ultrastructural observations in the rat bladder treated with N-butyl-N-(4-hydroxybutyl)nitrosamine

This study describes ultrastructural alterations of the interstitial stroma in the rat bladder epithelium during N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN)-induced bladder carcinogenesis using scanning (SEM) and transmission (TEM) electron microscopy with NaOH treatment. The results obtained with SEM demonstrated the occurrence and development of stroma protrusions which exhibited pipe-like structures in the rat bladder epithelium following administration of BBN. Number and size of blood vessel sections also gradually increased both in the stroma and within the layer of the proliferated epithelial cells as examined by light microscopy (LM) and TEM. In this study stroma alterations were not only observed in malignant lesions of rat bladder, but hyperplastic lesions were also accompanied by stroma alterations. It is suggested that: (1) the interstitial stroma of the rat bladder epithelium may exhibit pathological changes in structure and these changes may correlate with the progression of epithelial cell proliferation following administration of BBN and (2) one of the most important alterations in the stroma is the occurrence of neovascularization, which may induce structural modification of the stroma in the processes of bladder tumor growth and development.

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.

Microvessel quantitation in breast ductal invasive carcinoma. Correlation with proliferative activity, hormonal receptors and lymph node metastases

To investigate the correlation between tumor angiogenesis with axillary metastasis in breast cancer, we analyzed a series of 130 cases of infiltrating ductal carcinoma N.O.S. Tissue sections were stained with factor VIII-RA and microvessel quantitation was performed at x 400 magnification in the most vascular areas and expressed in vessels per mm2. Other variables such as tumor size, histologic grade, mitotic count, tumor necrosis, vascular invasion, skin involvement, anti-P.C.N.A. (proliferative cell nuclear antigen) and estradiol and progesterone receptors measured by an immunohistochemical method were determined. Statistical analysis of variance (AN-OVA) and Pearson's correlation coefficient were applied. The average of vessels per mm2 in tumors with metastases (n = 70) was 82.0 (median 74, SD 37.5), whereas in tumors without metastases (n = 60), it was 67.1 (median 64, SD 28.1). The difference was statistically significant (p < 0.01). However, the significance was lost when tumor size was introduced as a co-factor in a multifactorial analysis of variance. The number of vessels was unassociated with menopausal status, histologic grade, mitotic count, tumor necrosis, vascular invasion, skin involvement, estradiol and progesterone receptors and proliferative activity measured with anti-P.C.N.A. We conclude that in breast ductal invasive carcinoma, when tumor size is taken into consideration, angiogenesis is not associated with axillary lymph node metastases.

Prognostic value of microvessel quantitation in cisplatin treated FIGO 3 and 4 ovarian cancer patients

Primary ovarian carcinomas of 49 patients have been used to study the relation between microvessel counts and prognosis. All tumours were of the common epithelial type, FIGO 3 or 4, were treated by debulking surgery and cisplatin based chemotherapy. Primary tumour tissue obtained at surgery was embedded in paraffin, cut at 4 microns and stained with Ulex to accentuate the microvessels. The number of microvessels per unit area was counted according to a standardized protocol at a magnification of x 250 in 4 fields, which showed high field (R = 0.98) and acceptable case reproducibility (R = 0.70). Microvessell counts did not show associations with other prognostic variables such as FIGO stage, bulky disease-or-not, differentiation grade, DNA ploidy, volume percentage epithelium, mitotic activity index and mean nuclear area. In survival analysis, a tendency for worse prognosis with higher microvessel counts was found, although statistical significance was not reached (p = 0.25). Correction for volume percentage epithelium did not improve this result. Multivariate survival analysis did not reveal additional prognostic value of microvessel counts to other prognostic factors such as FIGO stage, bulky disease-or-not, volume percentage epithelium, mitotic activity index and mean and SD of nuclear area. In conclusion, although a tendency for worse survival with higher microvessel counts has been found, vascularity does not seem to have a significant impact on survival of adequately debulked advanced ovarian cancer patients treated with cisplatin.

Vasculature in Nontumorous Hypophyses, Pituitary Adenomas, and Carcinomas: A Quantitative Morphologic Study

Vascular supply is essential for tumor proliferation and metastasis formation. Correlation was noted between vascular density and tumor size as well as metastases in several tumor types. The aim of the present study was to assess vascular density in nontumorous hypophyses, pituitary adenomas, primary pituitary carcinomas, and carcinomas metastatic to the pituitary. Twenty nontumorous hypophyses, 87 endocrinologically active or inactive pituitary adenomas, 8 primary pituitary carcinomas, 8 metastatic carcinomas, and 10 randomly selected noninvasive and 6 invasive adenomas were included in the study. Tissues were fixed in formalin, embedded in paraffin, cut, stained with hematoxylin and eosin, PAS, and immunostained for adenohypophysial hormones as well as Factor VIII-related antigen using the streptavidin-biotin-peroxidase complex method. Four counts were performed: percentage of capillary area, number of vessels per field, percentage of endothelial cells, and number of endothelial cells per field. The results show that pituitary adenomas have significantly lower vascular densities as compared to nontumorous adenohypophyses. Prolactin-producing adenomas removed from untreated patients have the highest counts and growth hormone-producing adenomas the lowest counts. However, the observed differences among adenoma types are not of statistical significance. No differences are noted between noninvasive and invasive tumors. Primary pituitary carcinomas show no significant increase in vascular densities. Some metastatic tumors exhibit high vascularity. It can be concluded that pituitary adenomas have a limited capacity to induce angiogenesis. Lack of significant angiogenesis may play a role in the slow pace of pituitary tumor growth and rarity of metastases.

Tumour vascularity and basement membrane structure in breast cancer as related to tumour histology and prognosis

A series of 202 breast cancer biopsy specimens were analysed immunohistochemically for collagen IV to demonstrate basement membrane (BM) structures and blood vessels within tumour tissue. Integrity of the BM was graded into four categories and the number of vascular channels per square millimetre of tumour tissue were counted. Defective BM structures were significantly related to high grade, lack of tubule formation, invasive disease, high S-phase fraction and variability in nuclear size and shape. High vascular channel density was related to poor tumour differentiation and a high proliferation rate of cancer cells as well as to the absence of tubule formation, inconspicuous intraductal growth and low progesterone receptor content. High vascular density and defective BM structures were signs of poor prognosis and short recurrence-free survival in the entire cohort and also in local tumours. In multivariate analysis, the vascular density had independent prognostic value, as did the diameter, axillary lymph node status and mitotic rate. The counting of vascular channels within the tumour provides additional prognostic information in breast cancer, in contrast to analysis of the BM integrity which shows hardly any prognostic information additional to that provided by the special histological features, e.g. tubule formation and intraductal growth pattern.

Proliferation, basement membrane changes, metastasis and vascularization patterns in human breast cancer

Tumour cell proliferation shows a heterogeneous intratumour distribution. By comparison with the infiltrating component of breast cancers, the intraductal component has a significantly lower proliferation index. The cells at the periphery of infiltrating tumour strands have a higher proliferation activity than the cells in the core. A variable turn-over of basement membrane material is reported in infiltrating cancers. Increased amounts of type IV collagen are demonstrated in areas of periductal elastosis and of interstitial elastosis in breast cancer. Important parallels are found between metastatic tumour cells and the macrophages acting in the process of inflammation. We found evidence that displacements of tumour cells and macrophages are similar. Studies of vascularization in transplanted tumours cannot be extrapolated to man. A striking heterogeneity in the organization of vessels and in the expression of some markers is observed in human breast cancer.

Geographical mapping of metabolites in biological tissue with quantitative bioluminescence and single photon imaging

This article features a novel technique for measuring the spatial distribution of metabolites, such as ATP, glucose, and lactate, in rapidly frozen tissue. Concentration values are obtained in absolute terms and with a spatial resolution of single-cell dimension. The method is based on enzymatic reactions that link the metabolite of interest to luciferase with subsequent light emission. Using a specific array, cryosections are brought into contact with the enzymes in a well-defined, reproducible way inducing a distribution of light across the section with an intensity that is proportional to the metabolite concentration. The emitted light can be visualized through a microscope and an imaging photon counting system, and the respective image can be transferred to a computer for image analysis. Measurements in spherical cell aggregates with central necrosis demonstrate a close correlation between the distribution of ATP and of cellular viability at a microregional level. Similarly, ATP and glucose are correlated with the geometrical arrangement of more viable and more necrotic tissue regions in human melanomas xenografted in nude mice. Lactate did not show such a structure-related distribution in these tumours. Structure-related distributions of ATP, glucose, and lactate are found in cervix tumours of patients. In contrast to the heterogeneous distributions in tumours, the distribution patterns were much more homogeneous in normal tissues. Regional differences were present, but were much more gradual than in malignancies. This was illustrated for heart muscle where ATP concentrations were found that agreed with data in the literature, and that showed a decrease in periventricular areas.

The prognostic value of basement membrane morphology, tumour histology and morphometry in superficial bladder cancer

This analysis evaluated the prognostic importance of clinical, histological (WHO grade, papillary status, tumour-infiltrating lymphocytes) and morphometric factors (mitotic index, mean nuclear area, SD of nuclear area) in a cohort of 132 patients with a Ta-T1 transitional cell bladder cancer followed-up for over 8 years. Special attention was given on the state of the subepithelial basement membrane (BM) and subepithelial vascular density as demonstrated by type IV collagen immunostaining. Defects in the BM and dense vascular network were related to nodular growth pattern, high histological grade, rapid cancer cell proliferation and a dense inflammatory cell infiltrate (tumour-infiltrating lymphocytes, TIL) in tumour stroma. The most important predictor of progression was the mitotic index (P < 0.0001) followed by vascular density (P = 0.0054), the state of the BM (P = 0.0056), density of TIL (P = 0.0193), WHO grade (P = 0.0356) and papillary status (P = 0.0448). In univariate survival analysis the mitotic index (P < 0.0001), the state of the BM (P < 0.0001), subepithelial vascular density (P = 0.0013) and WHO grade (P = 0.01) predicted survival. In a multivariate analysis the mitotic index (P < 0.0001) and the state of the BM (P = 0.008) were independent predictors. The results show that the evaluation of the mitotic rate and investigation of the continuity of the BM should be done whenever the prognosis of Ta-T1 tumours of the bladder is assessed.