Cell proliferation markers in the transplanted canine transmissible venereal tumor

Adult male mongrel dogs were subcutaneously transplanted with the canine transmissible venereal tumor (TVT) on the hypogastric region. Twelve specimens of tumors were collected, half during the proliferative phase and the other half during the regressive phase. Fragments of the tumor were fixed in 10% buffered formalin and routinely processed for light microscopy. Sections of 4µm were stained by Schorr or AgNOR or either immunostained for MIB1 (Ki67). Schorr stain, AgNOR and MIB1 showed an increased proliferative activity through mitotic index, nuclear argyrophilic protein stain and cycling tumoral cells in the growing tumors, respectively. All of the three cell proliferation markers were able to distinguish the TVT in both evolution phases. MIB1 monoclonal antibody was the best in the morphologic evaluation of growth and regression of TVT. This resulted in higher values than AgNORs counting and mitotic index. MIB1 immunostaining was the most effective parameter of the proliferative activity of TVT. However, a significant correlation has been detected only between mitosis counting and AgNORs.

Assessment of cell proliferation and prognostic factors in canine mammary gland tumors

Three methods for the analysis of cell proliferation, mitotic index/10 high-power fields (10 HPF), mitotic index/four sets of 10 HPF (40 HPF), and MIB-1 index were evaluated in a series of canine mammary gland tumors, as well as the possible correlation between them. Fifty-six canine mammary gland tumors, including 23 benign and 33 malignant, were studied. In addition, the prognostic impact of mitotic index/10 HPF, and histological malignancy grade were evaluated in 17 malignant tumors, being seven ductal and 10 metaplastic carcinomas. The three methods used to evaluate cell proliferation were correlated with the prognostic impact of mitotic index/10 HPF and histological malignancy grade. The results showed a strong association between mitotic figure counts and MIB-1 index (P<0.0001). A correlation was observed between mitotic count per 40 HPF and MIB-1, and between mitotic index per 10 HPF and 40 HPF (P<0.05). Moreover, histological malignancy grade and mitotic figure counts were excellent prognostic factors during three-year follow-up (P<0.05). There was a correlation between the three methods used for the evaluation of cell proliferation and prognostic factors as observed in human breast cancer studies.

VEGFR-3 expression in breast cancer tissue is not restricted to lymphatic vessels

We examined the immunohistochemical reactivity for vascular endothelial growth factor receptor 3 (VEGFR-3), a protein playing an important role in lymphangiogenesis, in breast cancer. A retrospective series of 77 invasive ductal breast carcinomas was investigated. The relationship between VEGFR-3 expression and clinicopathologic parameters was examined for statistical significance using Pearson's chi-square (chi2) test and Fisher's exact test (when n<5). Threshold for significance was p<0.05. Patient age ranged from 31 to 77 years (mean: 55 years). The VEGFR-3 immunoreactivity was as follows: 5 cases were negative (6.5%), 35 + (45.4%), 27+ + (35.1%), and 10+ + + (13.0%). Reactions were positive for both lymphatic and blood vessels in several cases. VEGFR-3-positive reactions were more frequent in the tumor periphery than within the tumor. Immunoreactivity was also observed in myoepithelial cells surrounding both normal ducts and ducts with ductal carcinoma in situ. Statistical analysis of VEGFR-3 reactions was not significantly related to node status, microvessel density, and tumor grade. Ploidy showed a tendency towards significance (p=0.063); however, owing to the limited number of cases, statistical significance was not reached. VEGFR-3 lacks lymphatic vessel specificity and is also expressed in blood vessels, myoepithelial cells, and neoplastic cells.

Cell proliferation in feline normal, hyperplastic and neoplastic mammary tissue – an immunohistochemical study

The expression of a proliferation cell marker in neoplastic and non-neoplastic mammary tissue in 31 cats was assessed by immunohistochemistry in formalin-fixed paraffin-embedded samples using a monoclonal antibody against nuclear antigen Ki-67 (MIB-1). The results revealed that cell proliferation was more intense in hyperplastic than in normal mammary tissue. Carcinomas exhibited a higher MIB-1 index than benign tumours. There was also a positive correlation between proliferative activity and the histological grade of carcinomas. Fibroadenomatous change, which is considered to be hyperplastic and associated with favourable biological behaviour, exhibited high proliferative activity involving both epithelial and mesenchymal components. MIB-1 detected in formalin-fixed material with pre-treatment with antigen retrieval solution appeared to be a reliable marker of proliferation in feline mammary tumours, but further studies are needed to investigate the value of this proliferation marker in predicting clinical outcome and/or as a prognostic factor in feline mammary lesions.

Carcinoma of the ampulla of Vater associated with or without adenoma: a clinicopathologic analysis of 198 cases with reference to p53 and Ki-67 immunohistochemical expressions

Adenomatous areas are found frequently within or in the vicinity of carcinoma of the ampulla of Vater. This makes definite diagnosis difficult in the preoperative examination. The adenoma-carcinoma development hypothesis is generally accepted for colorectal tumors. Recently, a genetic alteration model during colorectal tumor development has attracted much attention, leading to various studies. We studied clinicopathologic features, prognostic factors, and the alteration of the p53 tumor suppressor gene using p53 immunohistochemical staining in pure adenomas, pure carcinomas, and carcinomas with adenomatous areas. A proliferative activity of the tumors using Ki-67 was also evaluated. Nine cases of pure adenoma and 198 cases of carcinoma of the ampulla of Vater were selected for this study. Among the 198 cases of thecarcinoma, 83 cases (42%) had adenomatous areas. Positivity of p53 immunohistochemical staining was 0% in pure adenomas, 36% in the adenomatous areas of carcinomas with adenomatous areas and 62% in the carcinomatous areas of carcinomas with adenomatous areas, and 56% in pure carcinoma. Accumulation of p53 protein and the Ki-67 labeling index revealed no significant difference in prognosis. The clinicopathological factors examined were as follows: degree of invasion of the surrounding tissue, such as duodenal wall; pancreatic parenchyma; the presence or absence of lymphatic permeation; venous invasion; perineural invasion; the presence of regional lymph node metastasis; and TNM stage. Each of the clinicopathological factors showed a significant difference. Multivariate analysis revealed strong predictors for a worse prognosis: presence of lymphatic permeation, invasion of the pancreas, and perineural invasion. In conclusion, our results are consistent with the adenoma--carcinoma development hypothesis. It would seem that the molecular events leading to p53 accumulation in neoplasms of the ampulla of Vater occur relatively late during the oncogenetic process. Moreover, we think it may be useful to refer to the p53 overexpression in the diagnosis of ampullary tumors.

Expression of TGF-alpha and EGFR in Breast Cancer and its Relation to Angiogenesis

Immunohistochemical analysis of the expression of transforming growth factor alpha (TGF-alpha) and its receptor, epidermal growth factor receptor (EGFR), was performed in a series of 86 invasive carcinomas of the breast. TGF-alpha immunostaining was observed in the majority of the cases (72.1%), both in epithelial cells and in adjacent stromal cells. EGFR was also present in tumors (34.2%) and in the endothelial cells (46.1% of the cases) near the tumors. A significant association was observed between TGF-alpha expression and angiogenesis evaluated by immunohistochemistry using an antibody against factor VIII-related antigen. No association was observed between TGF-alpha expression and other clinicopathologic features. In contrast, EGFR expression in the tumor was associated with features of poor prognosis, such as tumor size, histologic grade, lymph node status, estrogen receptor content, p53 expression, sialyl-Tn expression, and age. The presence of EGFR in endothelial cells was correlated to young patient age. We also observed an association of EGFR in endothelial cells and angiogenesis in tumors with a size of less than 2 cm. Inversely, in larger tumors, angiogenesis was only associated with tumor TGF-alpha expression. These results indicate that endothelial EGFR may play a role in the early steps of breast cancer angiogenesis.

Immunohistochemical study of hormonal receptors and cell proliferation in normal canine mammary glands and spontaneous mammary tumours

The expression of hormone receptors and their relationship to cell proliferation in six samples of normal canine mammary tissue, and 11 benign and 10 malignant mammary neoplasms from female dogs were assessed by immunohistochemistry in formalin-fixed paraffin-embedded samples, by using monoclonal antibodies against progesterone and oestrogen receptors, and nuclear antigen Ki-67 (MIB-1). Malignant tumours negative for progesterone receptors proliferated at higher rates than progesterone receptor-positive tumours, suggesting that the progression towards malignancy in spontaneous mammary tumours is accompanied by a decrease in hormonal steroid dependency. Only one malignant tumour was positive for oestrogen receptors.

Evaluation of cell proliferation, epidermal growth factor receptor, and bcl-2 immunoexpression as prognostic factors for patients with World Health Organization grade 2 oligodendroglioma

BACKGROUND

Prognostic factors in oligodendrogliomas are an area of controversy in neuropathology. Although grading and the study of some morphologic variables may be of value as prognostic parameters, the variability of postoperative disease free survival in patients with World Health Organization Grade 2 oligodendroglioma indicates that the biologic behavior of this entity remains unknown. The objective of the current study was to evaluate immunoexpression of the proliferation index (PI), epidermal growth factor receptor (EGFR), and bcl-2 as prognostic factors in patients with Grade 2 oligodendroglioma.

METHODS

In a series of 19 cases of pure Grade 2 oligodendroglioma, we assessed the mitotic count, labeling index for MIB-1 and PCNA, and immunoreactivity for EGFR and bcl-2 with semiquantitative parameters and compared these with postoperative disease free survival. Statistical analyses using the Cox-Mantel nonparametric test and Spearman correlation coefficient were used to evaluate the data.

RESULTS

Disease free survival was significantly shorter when the MIB-1 PI was > 5% (P = 0.0096) and the PCNA PI was > 9% (P = 0.00011) and when mitoses were observed (P = 0.00004). The paired variables also were found to correlate: MIB-1 versus PCNA (P = 0.04), MIB-1 versus mitotic count (P = 0.0184), and PCNA versus mitotic count (P = 0.0079). In all cases, there was immunoreactivity for EGFR; conversely, all cases were negative for bcl-2 in the cells with an oligodendrocyte phenotype.

CONCLUSIONS

The PI was found to correlate with the postoperative disease free survival in patients with Grade 2 oligodendroglioma; therefore, the authors suggest a possible subdivision of Grade 2 oligodendrogliomas into two groups based on the mitotic count and PI.

Microsatellite instability in medullary breast carcinomas

Microsatellite instability (MSI) has been reported to occur in a wide variety of sporadic tumours, such as colorectal and gastric cancers. MSI positivity has been associated with a particular clinico-pathologic profile, including the presence of abundant lymphoid infiltration, poor differentiation and a relatively good outcome for the patients. Since medullary breast carcinomas (MBCs) share these clinico-pathologic features with the MSI-positive tumours described above, we evaluated MSI in this particular histologic type of breast cancer. DNA of 24 MBC cases was extracted from formalin-fixed, paraffin-embedded tissue. The presence of MSI was analysed using BAT-26. We also searched mutations in 2 target genes: TGF-beta RII and BAX. Five cases of the series were also analysed for 1 (CA) dinucleotide tandem repeat sequence (D1S158), 8 tetranucleotide repeat sequences (D3S1358, D5S818, D7S820, D8S1179, D13S317, D21S11, FGA and VWA) and 1 pentanucleotide repeat (dAAAAT), localized in intron 1 of p53 gene. We found 2 carcinomas (8.3%) with BAT-26 instability. None of the cases had mutations in the "target genes", TGF-beta RII and BAX, including the 2 cases with BAT-26 instability. No MSI was observed using the panel of tetra- and pentanucleotide markers. Loss of heterozygosity was found in some loci. No significant difference in mean MIB-1 index according to RER status was observed. The low frequency of MSI in MBC is similar to that of other histologic types of breast cancer. Although MBCs share some clinico-pathologic features with colorectal and gastric carcinomas, which exhibit a high frequency of MSI, the underlying genetic events leading to this breast tumour are different from those leading to tumours of the digestive tract.

Phyllodes tumour of the breast: immunohistochemical study of 37 tumours using MIB1 antibody

In our study, the expression of Ki-67 antigen in phyllodes tumours of the breast was investigated in order to estimate its significance in assessing the grade of malignancy and in predicting the clinical behaviour of these tumours. Formalin-fixed and paraffin-embedded tissue specimens of 37 cases of phyllodes tumour of the breast (eight graded as malignant and 29 as benign according to histopathological criteria) and 20 breast fibroadenomas were stained by an immunoperoxidase technique, using the monoclonal antibody MIB1 directed against cell proliferation-associated Ki-67 antigen. A MIB1 index was calculated to express the percentage of MIB1 positive proliferating stromal cells. Our data indicate that there are statistically significant differences in MIB1 indices between histologically benign and malignant phyllodes tumours (alpha = 0.001), between benign phyllodes tumour and fibroadenoma (alpha = 0.01), and between malignant phyllodes tumour and fibroadenoma (alpha = 0.001). Our results also indicate a good correlation between the conventional grading of phyllodes tumours based on histological criteria and MIB1 indices. However, little predictive value of the MIB1 index in phyllodes tumours of the breast can be derived from our study.

Cellular proliferation in breast ductal infiltrating carcinoma. Correlation with clinical and histopathological variables

To evaluate four methods to study cellular proliferation (mitotic count, mitotic index, PCNA and MIB1) in a series of breast ductal invasive cancer NOS, and the possible correlations between these different methods and other pathological variables, we studied 110 ductal invasive carcinomas NOS specimens. Mitoses per 1000 tumor cells and per 10 HPF, and immunostaining for PCNA and MIB1 were evaluated. Other accepted prognostic factors such as tumor size, histologic grade, estrogen and progesterone receptors measured by immunostaining and axillary status were obtained. Correlation between the four methods to evaluate cellular proliferation and these other variables was performed. Mitotic count, mitotic index, PCNA and MIB1 showed a good rate of correlation (r = 0.71-0.53, p < 0.05), with the exception of MIB1-mitotic index which was weak (r = 0.38, p < 0.05). A strong association between cellular proliferation, with independence of the method applied, and histologic grade, ER and PR was obtained. No association was observed with tumor size and lymph node involvement. In conclusion, there was a strong correlation between the four methods to evaluate cellular proliferation. Mitotic count (per 10 HPF) and MIB1 show a better correlation with other morphological variables. None of the evaluated methods are associated with the tumor size and axillary status, suggesting that mitotic count is the most accurate method to analyse cellular proliferation in routine practice.

Pseudoangiomatous hyperplasia of mammary stroma associated with gynaecomastia

AIMS

To evaluate the prevalence of pseudoangiomatous hyperplasia of mammary stroma in gynaecomastia and its immunohistochemical profile in this setting.

METHODS

Eighty eight cases of gynaecomastia recovered from the files of the department of pathology, Botucatu School of Medicine from 1976 to 1996 were studied. In the cases associated with pseudoangiomatous hyperplasia of mammary stroma, immunoreactivity for cytokeratins (CAM 5.2), vimentin, CD34, factor VIII related antigen, and the oestrogen and progesterone receptors were studied.

RESULTS

Pseudoangiomatous hyperplasia of mammary stroma was found in 21 of 88 cases of gynaecomastia (23.8%). In all cases, the cells lining the spaces were positive for vimentin, whereas CAM 5.2 and factor VIII related antigen were consistently negative. Nineteen of the 21 cases showed immunoreactivity for CD34. Ductal epithelial cells were positive for both the oestrogen receptor and the progesterone receptor, whereas stromal cells were negative.

CONCLUSIONS

Pseudoangiomatous hyperplasia of mammary stroma was present in approximately one quarter of the cases of gynaecomastia. This immunohistochemical study confirms the mesenchymal origin of the stromal cells that line the pseudovascular spaces, as has been found in female cases of pseudoangiomatous hyperplasia of mammary stroma.

CD26 (Dipeptidyl Aminopeptidase IV) Expression in Normal and Diseased Human Thyroid Glands

The objective of the present study was to investigate CD26 (dipeptidyl aminopeptidase IV) expression in normal and diseased thyroids and its relation to differentiation and cell proliferation. CD 26 was also evaluated as a possible marker of malignancy in thyroid neoplasias. A total of 38 normal thyroids and 117 diseased thyroids (neoplastic and non-neoplastic) were evaluated. CD26 and thyroglobulin (Tg) expression was determined by analyzing at least 200 cells/specimen. A minimum of 500 cells/specimen were counted to calculate the MIB-1-positive cell rate expressed as a percentage of total nucleated epithelial cells. CD26 expression was absent in all thyroids from fetuses and children. Among the adults, 7.1 % had CD26 expression only in oncocytic metaplastic areas. In 3 of the 7 elderly subjects, CD26 expression was present in 0.2-90% of epithelial cells. CD26 expression was observed in all diseased thyroids. Since this enzyme is also expressed in benign conditions, it is not useful as a marker of malignancy. There was no relationship between CD26 and Tg expression. The MIB-1-positive cell rate was found to be low for all kinds of thyroid tissues, and when the cell proliferation rate was analyzed according to CD26 expression, a greater cell proliferation rate was found in CD26-positive differentiated (follicular and papillary) carcinomas than in CD26-negative carcinomas. These results demonstrate that expression of this enzyme is related to the proliferative activity of follicular cells.

Angiogenesis in breast cancer is related to age but not to other prognostic parameters

Angiogenesis is essential for tumour growth and metastasis. In spite of its relevant biological significance, recent studies have produced conflicting results regarding the capacity of microvessel quantifications in breast carcinomas to predict patients' outcome and the existence of metastasis. In order to provide further information in this issue, we evaluated tumour angiogenesis in a series of 45 primary breast carcinomas (mean age: 55.3 +/- 14.2) and examined their association with established or potentially useful prognostic parameters. Microvessels were highlighted by immunohistochemical staining for factor VIII-related antigen and counted in the three most vascularized areas in a 200 x field (0.74 mm2) by four observers simultaneously. Results were analysed for the average vessel count of each case. The mean intratumoural microvessel count was 57.7 +/- 24.4 (range: 24.3 to 127.7). We found a statistically significant association between angiogenesis and age. The microvessels count in patients younger than 50 years was 67.8 +/- 26.4, from 51 to 70 years, 52.0 +/- 22.8 and over 71 years, 46.1 +/- 14.2 (p = 0.03). Node positive patients had slightly higher microvessel counts (60.3 +/- 25.3) than node negative ones (54.4 +/- 23.5); this difference was not significant (p = 0.42), even when we considered each age group per se. No association was found between angiogenesis and tumour size, histologic grade, estrogen receptor, MIB-1 index, ploidy and expression of p53 and c-erbB-2. Our results suggest that invasive breast carcinoma-induced angiogenesis is age-dependent.

Expression of sialyl-Tn in breast cancer. Correlation with prognostic parameters

To investigate the expression of a simple mucin-type carbohydrate antigen (Sialyl-Tn/STn) and its putative relationship with established or potentially useful clinico-pathologic prognostic parameters in breast cancer, we studied forty-six cases of invasive breast carcinoma in formalin-fixed, paraffin-embedded tissue sections. STn antigen was detected by the HB-STn antibody using an avidin-biotin-peroxidase method. The parameters studied were tumour size, histologic grade, nodal status, proliferative index (with MIB-1), ER expression, ploidy, c-erbB-2 and p53 expression. STn expression was observed in 18 cases (39%) of breast cancer. The expression of STn was associated with axillary node metastasis, ER negativity and c-erbB-2 expression. A tendency towards an association between STn immunoreactivity and high histologic grade was also found. No correlation was observed between STn immunoreactivity and age, tumour size, proliferative index, ploidy and p53 expression. We conclude that the detection of STn immunoreactivity may be useful for predicting the likelihood of lymph node metastasis and that the outcome of patients with breast cancer should be further investigated in order to find whether or not the data of the present study are confirmed in larger series.