neu overexpression correlates with extent of disease in large cell ductal carcinoma in situ of the breast

C-erbB-2 in Serum of Patients Receiving Fractionated Paclitaxel Chemotherapy

Humanized anti-c-erbB-2 antibodies (Herceptin®) in a weekly schedule are a new therapeutic option for the treatment of c-erbB-2-positive, advanced breast cancer (ABC). Addition of Herceptin® to first-line chemotherapy for c-erbB-2 overexpressing ABC increased anticancer activity in a randomized phase III trial. However, except from standard UICC response criteria, there are hitherto no recommendations as to how to monitor Herceptin® therapy. In a therapy optimizing study with weekly dose-intensified paclitaxel monotherapy (schedule: 90 mg/m2 weekly x 6, q9w), we correlated the clinical course of stage IV breast cancer in UICC criteria with the course of the shed c-erbB-2 protein fragment and the CA 27.29 serum level. Serum samples were taken weekly from 35 patients to measure the serum c-erbB-2 and CA 27.29 protein levels over time. Up to now, 10 patients (28.5%) are c-erbB-2 positive (>15 U/mL), with a median baseline protein expression of 65 U/mL. While the overall response rate in the study is 36%, the response rate among c-erbB-2-positive patients is 62%, indicating a high sensitivity of c-erbB-2 positive patients to dose-intense paclitaxel treatment. In all responders the c-erbB-2 serum level decreased below the detection limit either before the clinical diagnosis of response or by the end of the next cycle. However, the normalization of the c-erbB-2 serum level was not specific for responders as patients with stable or progressive disease presented normalized levels or a >50% decrease of the baseline level, too. The courses of the c-erbB-2 protein levels correlated closely with the courses of CA 27.29. The decrease in the serum c-erbB-2 oncoprotein level might indicate a regression of c-erbB-2 positive tumor load. This may even happen in progressive disease according to UICC criteria when the c-erbB-2-negative tumor fraction progresses while the c-erbB-2-positive fraction is controlled. Another explanation would be that the mechanisms of c-erbB-2 shedding change under chemotherapy, with less of the c-erbB-2 protein fragment being released to the serum, which would make the c-erbB-2 positive tumor cells a better target for anti-c-erbB-2 antibody treatment.

C-Erb-b2 oncogene expression in intraductal proliferative lesions of the breast

The ductal intraepithelial neoplasia (DIN) classification which proposes new approaches to the diagnosis, terminology and differential diagnosis of intraductal proliferative lesions of the breast was applied to a series of female patients comprising C-erbB2 oncogene expression which may serve as an adjunct to the morphology by immunohistochemistry. The study was performed using the data of 94 patients. There was no difficulty encountered in the diagnosis of intraductal hyperplasia (IDH). In patients with Atypical Ductal Hyperplasia (AIDH), the diagnosis could be made by using the 2-mm rule of the DIN classification in patients who exhibited cytologic and structural characteristics of Ductal Carcinoma in Situ (DCIS) alone or in conjunction with classical IDH patterns. However, in lesions that mimicked classical IDH patterns despite displaying cytological features of in situ carcinomas, the experience and view point of the pathologist played a more prominent role. When the DIN classification criteria were applied to grade DCIS lesions, although the system was found to be practical, it did not provide adequate differentiation in intermediate grade (grade II-DIN 2) patients and further improvement was considered desirable. Fourty-five cases (47.8%) IDH, 19 (20.2%) AIDH, and 30 (31.9%) were DCIS. There were statistically significant differences in the levels of c-erbB2 oncogene expression between IDH, AIDH and DCIS lesions (p<0.001). In DCISs, grade, cell size, pleomorphic nuclear atypia showed statistically significant associations with c-erbB2 oncogene expression. These results suggest that c-erbB2 oncogene expression is a valuable marker in the differential diagnosis and prognostic evaluation of patients with intraductal proliferative lesions.

Arecoline induced disruption of expression and localization of the tight junctional protein ZO-1 is dependent on the HER 2 expression in human endometrial Ishikawa cells

Background

Approximately 600 million people chew Betel nut, making this practice the fourth most popular oral habit in the world. Arecoline, the major alkaloid present in betel nut is one of the causative agents for precancerous lesions and several cancers of mouth among those who chew betel nut. Arecoline can be detected in the human embryonic tissue and is correlated to low birth weight of newborns whose mothers chew betel nut during pregnancy, suggesting that arecoline can induce many systemic effects. However, few reports exist as to the effects of arecoline in human tissues other than oral cancer cell lines. Furthermore, in any system, virtually nothing is known about the cellular effects of arecoline treatment on membrane associated signaling components of human cancer cells.

Results

Using the human Ishikawa endometrial cancer cell line, we investigated the effects of arecoline on expression, localization and functional connections between the ZO-1 tight junction protein and the HER2 EGF receptor family member. Treatment of Ishikawa cells with arecoline coordinately down-regulated expression of both ZO-1 and HER2 protein and transcripts in a dose dependent manner. Biochemical fractionation of cells as well as indirect immunofluorescence revealed that arecoline disrupted the localization of ZO-1 to the junctional complex at the cell periphery. Compared to control transfected cells, ectopic expression of exogenous HER2 prevented the arecoline mediated down-regulation of ZO-1 expression and restored the localization of ZO-1 to the cell periphery. Furthermore, treatment with dexamethasone, a synthetic glucocorticoid reported to up-regulate expression of HER2 in Ishikawa cells, precluded arecoline from down-regulating ZO-1 expression and disrupting ZO-1 localization.

Conclusion

Arecoline is known to induce precancerous lesions and cancer in the oral cavity of betel nut users. The arecoline down-regulation of ZO-1 expression and subcellular distribution suggests that arecoline potentially disrupts cell-cell interactions mediated by ZO-1, which may play a role in arecoline-mediated carcinogenesis. Furthermore, our study has uncovered the dependency of ZO-1 localization and expression on HER2 expression, which has therefore established a new cellular link between HER2 mediated signaling and apical junction formation involving ZO-1.

HER2 protein overexpression in estrogen receptor-positive ductal carcinoma in situ of the breast: frequency and implications for tamoxifen therapy

Recent clinical data have suggested that the efficacy of tamoxifen in reducing the risk of local recurrence following lumpectomy and radiation therapy in patients with ductal carcinoma in situ (DCIS) is limited to patients with estrogen receptor (ER)-positive lesions. However, it is currently not known if HER2 protein overexpression might be associated with reduced tamoxifen benefit in patients with ER-positive DCIS, as has been suggested in patients with ER-positive invasive breast cancer and in preclinical models. Moreover, the frequency of HER2 overexpression in ER-positive ductal carcinoma in situ has not been previously evaluated in detail. To address this issue, we studied ER expression and HER2 overexpression in 148 cases of DCIS using a sensitive double immunostaining technique and assessed the frequency of ER expression and HER2 overexpression in relation to each other and in relation to DCIS grade. Overall, ER expression was seen in 114 cases (77%) and HER2 protein overexpression was seen in 42 cases (28%). Of 114 ER-positive ductal carcinoma in situ, 14 (12%) showed concurrent HER2 protein overexpression, and all 14 of these DCIS lesions were of high nuclear grade. In addition, in all 14 ER-positive DCIS cases that showed HER2 overexpression, double immunostaining demonstrated that ER and HER2 protein were coexpressed by the same neoplastic cells. We conclude that a subset of ER-positive DCIS show concomitant overexpression of HER2 protein. Whether or not HER2 overexpression is associated with a diminished response to tamoxifen in patients with ER-positive DCIS will require investigation in clinical outcome studies.

Positive margins following surgical resection of breast carcinoma: Analysis of pathologic correlates

BACKGROUND AND OBJECTIVES

Histologic margin positivity represents a significant source of adverse clinical outcome affecting breast conservation therapy for in situ or invasive malignancy. Elucidation of factors associated with positive margin status might clarify and improve local therapy strategies. In order to define our experience with margin positivity and to identify relevant pathologic criteria, we retrospectively analyzed the cases of 143 patients who underwent resections for carcinoma with intent of breast conservation between 1995 and 1999.

METHODS

Histologic features and indices of biologic aggressiveness were compared among tumors resected with positive versus negative margins in order to determine whether such markers could be used to anticipate outcome.

RESULTS

Twenty-eight pathologic specimens were identified to possess histologically positive margins. Twenty-six patients underwent additional operative procedures. Of the 26 re-excision specimens, 17 (65%) contained residual malignancy. Statistical analysis demonstrated that margin positivity correlated with in situ histology and with Her 2/neu positivity.

CONCLUSIONS

These data suggest certain pathologic factors that may portend difficulty in achieving negative resection margins in patients in whom breast conservation therapy is considered.

The role of heregulin-alpha as a motility factor and amphiregulin as a growth factor in wound healing

Wound healing is a complex process of which growth and motility are essential features. The aim of this study was to search for keratinocyte-derived secreted factors that may play a role in these mechanisms, and their corresponding receptors. Growth and motility factors were purified from conditioned medium from cultured primary keratinocytes. Receptor and growth factor expression profiles were investigated by immunohistochemical, western blotting, and in situ hybridization analysis on cultured keratinocytes and tissue sections derived from chronic wounds. The most potent autocrine growth factor for keratinocytes, which it was possible to purify and sequence from keratinocyte-conditioned medium, is amphiregulin. Its receptor HER-1 is up-regulated on the membranes of keratinocytes lining the edge of the wound. From the same keratinocyte-conditioned medium, heregulin-alpha was purified as a potent motility factor for keratinocytes. Its receptor is HER-3, which is up-regulated on the membranes of keratinocytes lining the edge of the wound and on keratinocytes that had migrated towards the centre of the wound. HER-4 - another receptor for heregulin-alpha - is weakly present in occasional cells near the edge of the wound. The co-receptor for HER-3 and HER-4 is HER-2/neu, which is also present in epidermal cells but not overexpressed. This study shows that heregulin-alpha is a potent motility factor for normal epithelial cells and that it plays a central role in the process of wound healing of stratified epithelia. Heregulin-alpha has already been shown to be the motility factor leading to migration of HER-2/neu-overexpressing breast cancer cells. The role of amphiregulin as a growth factor and of heregulin-alpha as a motility factor for keratinocytes in epidermal and mucosal wound healing parallels their motility and growth induction in carcinogenesis.

Molecular and biologic markers of premalignant lesions of human breast

There is currently great interest in the detection and characterization of putative precursor breast cancer lesions because of the possibility of chemoprevention. Knowledge of the biologic features of premalignant lesions, although limited, is rapidly evolving. Premalignant breast lesions have been examined for the presence of genetic alterations and for the expression of biomarkers such as the estrogen receptor (ER), Ki67, p53, and HER2/neu. Data obtained from genetic studies of precursor breast lesions clearly support the contention that genetic alterations begin quite early in selected subsets of histologically benign lesions. Although the results of biomarker expression profiles have been contradictory, most studies agree that precursor lesions significantly overexpress ER and that progressive alterations in ER expression accompany the transition of normal cells to hyperplastic lesions and carcinoma in situ. So far, the collected evidence indicates that precursor lesions in the breast demonstrate biomarker expression profiles and genetic abnormalities that are distinct from those of terminal ductal lobular units but share some of these features with invasive tumors. Future research in this field is urgently needed to identify specific biomarkers of prognostic and predictive value, which can help not only in the selection of patients for chemopreventive therapy but in monitoring the progression of high-risk lesions.

The basic biology of HER2

Human epidermal growth factor receptors (HER/erbB) constitute a family of four cell surface receptors involved in transmission of signals controlling normal cell growth and differentiation. A range of growth factors serve as ligands, but none is specific for the HER2 receptor. HER receptors exist as both monomers and dimers, either homo- or heterodimers. Ligand binding to HERI, HER3 or HER4 induces rapid receptor dimerization, with a marked preference for HER2 as a dimer partner. Moreover, HER2-containing heterodimers generate intracellular signals that are significantly stronger than signals emanating from other HER combinations. In normal cells, few HER2 molecules exist at the cell surface, so few heterodimers are formed and growth signals are relatively weak and controllable. When HER2 is overexpressed multiple HER2 heterodimers are formed and cell signaling is stronger, resulting in enhanced responsiveness to growth factors and malignant growth. This explains why HER2 overexpression is an indicator of poor prognosis in breast tumors and may be predictive of response to treatment. HER2 is a highly specific and promising target for new breast cancer treatments. The recombinant human anti-HER2 monoclonal antibody (rhuMAb-HER2, trastuzumab, Herceptin) induces rapid removal of HER2 from the cell surface, thereby reducing its availability to heterodimers and reducing oncogenicity.

Similarity in expression of cell cycle proteins between in situ and invasive ductal breast lesions of same differentiation grade

There is increasing evidence that there are different progression routes leading to invasive breast cancer, depending on histology and differentiation grade. The aim of this study was to determine alterations in the expression of proteins involved in proliferation and apoptosis in non-invasive and invasive ductal breast lesions. Immunohistochemistry was performed on 106 usual ductal hyperplasias (UDH), 61 DCIS lesions and 53 invasive ductal breast carcinomas. Increased proliferation (Ki67), overexpression of cyclin D1, HER-2/neu, p21 and p53, and decreased expression of bcl-2 and p27 could already be found in UDH. Significant differences between UDH and DCIS lesions were found for only one protein when UDH was compared with well-differentiated DCIS (p27), for three proteins when compared with intermediately differentiated DCIS (p21, cyclin D1, Ki-67), and for all proteins when compared with poorly-differentiated DCIS. Comparing DCIS with invasive lesions of same differentiation grade, proliferation was elevated in the invasive lesions. Altered expression of the other proteins was in general only slightly increased in the invasive lesion compared with DCIS. The number of proteins with altered expression per lesion was highest in poorly-differentiated lesions and was comparable between DCIS and invasive cancer of the same differentiation grade. In conclusion, the biggest changes in expression of these proliferation and apoptosis related proteins appear to occur during the transition from hyperplasia to DCIS; they probably play a minor role in the transition from DCIS to invasive breast lesion of same differentiation grade. Well-differentiated in situ and invasive breast lesions share many of the aberrations in expression of these proteins, as do poorly-differentiated in situ and invasive lesions. However, there are many differences between the well and poorly-differentiated lesions. This further supports the existence of different progression routes leading to breast cancer.

Pathobiologic findings in DCIS of the breast: morphologic features, angiogenesis, HER-2/neu and hormone receptors

With the increasing incidence of ductal carcinoma in situ (DCIS) of the breast and its relationship to invasive breast carcinoma, it is important to understand the biology of this entity. We report on a hospital-based survey of 219 case subjects with DCIS of the breast without associated invasive carcinoma diagnosed between 1982 and 1994. The cases of DCIS were analyzed for architectural type, size, nuclear grade, necrosis, calcification, periductal fibrosis, neovascularization, estrogen receptor (ER), progesterone receptor (PR), and HER-2/neu expression. Periductal neovascularization was associated with tumor size, microcalcifications, periductal fibrosis, and HER-2/neu overexpression. Expression of ER and PR was observed in 60 and 62% of the cases, respectively, and HER-2/neu overexpression in 28% of the cases. ER and PR expression were both inversely associated with comedo histology and nuclear grade. HER-2/neu overexpression was positively associated with comedo histology, high nuclear grade, and periductal neovascularization and was inversely correlated with both ER and PR expression. High nuclear grade was positively associated with comedocarcinoma, necrosis, microcalcification, and periductal fibrosis. The role of these molecular/pathologic markers in the biology of DCIS and their potential clinical implications are discussed.

Biological features of premalignant disease in the human breast

Most human invasive breast cancers (IBCs) arise from preexisting benign lesions. There are many types of benign lesions in the human breast and only a few appear to have significant premalignant potential (atypical hyperplasias and in situ carcinomas). These lesions are relatively common and only a small proportion progress to IBC. They are currently defined by their histological features and their prognosis is imprecisely estimated from indirect evidence based on epidemiological studies. Although lesions within specific categories look alike, they must possess morphologically silent biological differences motivating some to remain stable and others to progress. Understanding the biological changes responsible for the development and progression of premalignant disease is a very active area of medical research. Progress in this area may provide new opportunities for breast cancer prevention by providing strategies to treat premalignant lesions before they develop or become cancerous. A large number of biological features have been evaluated in this setting during the past decade. This review discusses a few features that appear to be particularly important and have been studied in a relatively comprehensive manner.

Ductal carcinoma in situ. Implications for screening mammography

Ductal carcinoma in situ (DCIS) now represents 20% of all newly diagnosed breast cancers because of increased detection by screening mammography. Twenty year relative survival rates are 97%. Postsurgical and histological studies and recent molecular biological studies indicate that most cases of DCIS will progress to invasive carcinoma if not detected by mammography. Screening mammography studies support the need for annual versus less frequent screenings to detect DCIS before further progression.

Carcinoma in situ of the breast: correlation of histopathology to immunohistochemical markers and DNA ploidy

In a consecutive and unselected series of 178 cases of carcinoma in situ of the breast (CIS), comprising both ductal (DCIS) and lobular type (LCIS), and a series of 48 cases of invasive carcinoma (IC) with predominance of DCIS, the association between histopathology, immunohistochemical markers (ER, PgR, MIB-1, c-erbB-2, and p53), and DNA ploidy was investigated, in order to discriminate biologically different groups. In DCIS, significant correlation was shown between large nuclear size and comedonecrosis, both of which showed also strong association to DNA aneuploidy, high proliferation activity, low steroid receptor content, and overexpression of c-erbB-2 and p53 factors that may indicate an aggressive behavior. Small nuclear CIS, whether LCIS or DCIS, on the contrary, were DNA diploid with low proliferation, and no cases showed overexpression of c-erbB-2 and p53. Heterogeneity with respect to the investigated parameters was also a frequent finding that may reflect a development complexity. In IC, comparison of the DCIS and the invasive component showed similar patterns. No significant differences were shown between DCIS without and with invasion. This may indicate that none of the investigated parameters on its own are essential for the event of invasion.

The HER-2/neu oncogene: prognostic factor, predictive factor and target for therapy

The HER-2/neu oncogene encodes a transmembrane tyrosine kinase receptor with extensive homology to the epidermal growth factor receptor. HER-2/neu has been widely studied in breast cancer. The potential value of HER-2/neu status for the prediction of disease outcome and response to therapy in breast cancer is presented in the light of a series of recently published studies showing a range of impact on the outcome of patients treated with hormonal, cytotoxic and radiation therapies. This review includes the application of serum-based HER-2/neu testing and the use of antibody-based therapies directed against the HER-2/neu protein and their potential to become a new modality for breast cancer treatment.

Widespread chromosomal abnormalities in high-grade ductal carcinoma in situ of the breast. Comparative genomic hybridization study of pure high-grade DCIS

For a variety of technical reasons it is rarely possible to study cytogenetic abnormalities in ductal carcinoma in situ (DCIS) using traditional techniques. However, by combining molecular biology and computerized image analysis it is possible to carry out cytogenetic analyses on formalin-fixed, paraffin-embedded tissue, using comparative genomic hybridization (CGH). The purpose of this study was to identify the prevalence of chromosomal amplifications and deletions in high-grade DCIS and to look specifically for unique or consistent abnormalities in this pre-invasive cancer. Twenty-three cases of asymptomatic, non-palpable, screen-detected, high-grade DCIS were examined using CGH on tumour cells obtained from histology slides. All cases showed chromosomal abnormalities. A wide variety of amplifications and deletions were spread across the genome. The most frequent changes were gains of chromosomes 17 (13 of 23), 16p (13 of 23), and 20q (9 of 23) and amplifications of 11q13 (22 of 23), 12q 24.1-24.2 (12 of 23), 6p21.3 (11 of 23), and 1q31-qter (6 of 23). The most frequent deletions were on 13q 21.3-q33 (7 of 23), 9p21 (4 of 23), and 6q16.1 (4 of 23). These findings indicate that high-grade DCIS is, from a cytogenetic viewpoint, an advanced lesion. There was no absolutely consistent finding in every case, but amplification of 11q13 was found in 22 of the 23 cases. The precise significance of this is unknown at present. This region of chromosome 11q harbours a number of known oncogenes, including cyclin D1 andINT2. It is likely that many of these findings are the result of accumulated chromosomal abnormalities, reflecting an unstable genome in established malignancy.

The HER-2/neu oncogene in breast cancer: prognostic factor, predictive factor, and target for therapy

The HER-2/neu oncogene encodes a transmembrane tyrosine kinase receptor with extensive homology to the epidermal growth factor receptor. HER-2/neu has been widely studied in breast cancer. In this review, the association of HER-2/neu gene and protein abnormalities studied by Southern and slot blotting, immunohistochemistry, enzyme immunoassays, and fluorescence in situ hybridization with prognosis in breast cancer is studied in depth by review of a series of 47 published studies encompassing more than 15,000 patients. The relative advantages of gene amplification assays and frozen/fresh tissue immunohistochemistry over paraffin section immunohistochemistry are discussed. The significance of HER-2/neu overexpression in ductal carcinoma in situ and the HER-2/neu status in uncommon female breast conditions and male breast cancer are also considered. The potential value of HER-2/neu status for the prediction of response to therapy in breast cancer is presented in the light of a series of recently published studies showing a range of impact on the outcome of patients treated with hormonal, cytotoxic, and radiation therapies. The evidence that HER-2/neu gene and protein abnormalities in breast cancer predict resistance to tamoxifen therapy and relative sensitivity to chemotherapy regimens including adriamycin is presented. The review will also evaluate the status of serum-based testing for circulating the HER-2/neu receptor protein and its ability to predict disease outcome and therapy response. In the final section, the review will briefly present preliminary data concerning the use of antibody-based therapies directed against the HER-2/neu protein and their potential to become a new modality for breast cancer treatment. The recently presented phase III clinical trial evidence that systemic administration of anti-HER2 antibodies (Herceptin), alone and in combination with cytotoxic chemotherapy in patients with HER-2/neu overexpressing primary tumors, can increase the time to recurrence and overall response rates in metastatic breast cancer is reviewed.

ERBB2 oncogene in human breast cancer and its clinical significance

We reveiwed the relationships between ERBB2 amplification and/or overexpression in human breast cancer and the clinicopathological parameters described in the literature (97 studies involving 22,616 patients) in order to draw conclusions regarding its clinical interest. The mean of ERBB2 positivity (26%, ranging from 5 to 55%) is not dependent on the method used to evaluate ERBB2 amplification or overexpression. Despite the discrepancies observed between the different studies, several associations between ERBB2 positivity and the classical clinicopathological parameters were noted. There are clear relationships between ERBB2 positivity and the lack of steroid receptors, the histological subtypes of mammary tumours (ductal invasive and in situ), worse histological and nuclear grades, aneuploidy and high rate of proliferation. In univariate analyses, ERBB2 is strongly associated with poor prognosis. All these data indicate that ERBB2 is a marker of aggressiveness of the tumour. However, ERBB2 does not retain a clinical prognostic significance in multivariate analyses, since it is associated with several strong prognostic parameters. When considering the prognostic value of ERBB2 in relation to treatment, a significantly worse survival of the treated patients is noted in ERBB2 positive patients. This suggest that ERBB2 could be a marker of reduced response to chemotherapy and hormonal treatment. With respect to the tumour response to treatment, the results, provided as yet by pilot studies, remain controversial and further investigations are necessary to evaluate the predictive value of ERBB2. Finally, new therapeutic approaches targeting the cells overexpressing ERBB2 have been developed.

Angiogenesis and inflammation in ductal carcinoma in situ of the breast

Several recent studies suggest that vascular density may be an independent prognostic indicator in invasive carcinoma of the breast. Increased vascularity has also been shown in ductal carcinoma in situ (DCIS). The prognostic significance of the inflammatory infiltrate in mammary carcinoma is more controversial, but it could affect angiogenesis by releasing angiogenic factors and digesting matrix. Vascularity and inflammation have been studied in 41 examples of pure DCIS, classified using the method of Holland et al. Immunohistochemistry was performed with antibodies to von Willebrand factor, CD3, CD8, CD45RO, CD45RA, CD20, CD68, and c-erB-2. The main pattern of inflammation was clusters of B and T cells situated either adjacent to involved ducts or in the interductal stroma. Typically, these clusters were around vessels with plump endothelium suggestive of high endothelial venules. A less prominent pattern was a diffuse stromal infiltrate of macrophages and T cells. There were two patterns of increased vascularity associated with DCIS: necklaces of vessels close to the involved ducts and vessels arranged diffusely in the interductal stroma. Each pattern of inflammation and of vascularity was graded semi-quantitatively. Increased stromal vascularity was associated with the perivascular clusters of inflammation; both were associated with c-erB-2 expression and extent of the DCIS. Necklaces of vessels were associated with the diffuse inflammation. Perivascular inflammation and c-erB-2 (but neither pattern of vascularity) were associated with poor differentiation of the DCIS. Thus, different patterns of inflammation are associated with different patterns of vessels. The clusters of B and T cells may be recruited via high endothelial venules induced by the DCIS. Cytokines released by the DCIS and/or the inflammatory cells (clusters or diffuse) may stimulate the two patterns of new vessel formation.

Histological grade in invasive ductal carcinoma of breast correlates with the proliferative activity evaluated by BrdU: an immunohistochemical study including correlations with p53, c-erbB-2 and estrogen receptor status

Thirty cases of invasive ductal carcinoma of the breast were classified to histological subtype according to the General Rules for Clinical and Pathological Recording of Breast Cancer of the Japanese Breast Cancer Society and histologically graded using the Nottingham method and the correlation of histology with proliferative activity was investigated using bromodeoxyuridine (BrdU). In addition, the overexpression of p53 protein, c-erbB-2 oncoprotein and estrogen receptor (ER) were immunohistochemically examined in order to discuss the relationship with histological subtype and histological grade. Histological grade correlated positively to the BrdU labeling index (LI) and overexpression of p53. High grade carcinoma demonstrated c-erbB-2 more frequently and exhibited a low incidence of ER. However, no significant relationship was found between BrdU LI, overexpression of p53 and c-erbB-2 and histological subtype. These results suggest that the histological grade does represent the proliferative activity of tumor cells and that adding the histological grade to the pathological diagnosis in invasive ductal breast carcinoma may be useful from the clinicopathological aspect concerning tumor behavior.

The neu-protein and breast cancer

The neu-protein is overexpressed in about 20% of invasive duct cell carcinomas of the breast. The only reliable sign for neu-overexpression by immunohistochemistry is membrane staining. Its overexpression is correlated with decreased overall survival and disease free survival due to increased metastatic activity of neu-overexpressing tumour cells. This increased metastatic potential is a consequence of the motility enhancing activity of the neu-protein, which is exclusively expressed on pseudopodia, and to a lesser extent of its growth stimulating effect. From a clinical point of view, the assessment of neu-overexpression in breast cancer might become a useful tool in the future treatment of patients by chemotherapy, since patients whose tumour shows neu-overexpression benefit from higher doses of chemotherapy. The molecule plays a key role in the pathogenesis of Paget's disease of the breast. A chemotactic factor which is secreted by epidermal keratinocytes attracts the Paget cells to spread into the epidermis and acts via the neu-protein. In ductal carcinoma in situ, the combination of neu-overexpression and large cell type is highly correlated with extent of disease and therefore neu-overexpression might be a predictive marker for recurrence of disease after tumour resection.