Showing papers in "Breast Cancer Research and Treatment in 1995"
TL;DR: The methods of highlighting intratumoral vessels are reviewed and the techniques for counting these vessels for assessing iMVD are described, which exist not only in breast carcinoma, but also in other solid tumors.
Abstract: Abundant evidence has shown that tumor growth and metastasis are dependent upon tumor angiogenesis (TA). TA refers to the growth of new vessels toward and within the tumor. Until TA occurs, tumors grow no larger than 2–4 mm in diameter. Also, TA is necessary at the beginning and at the end of the metastatic cascade of events. Thus, it seems reasonable that increasing intratumoral microvascular density (iMVD) might correlate with greater tumor aggressiveness, such as a higher frequency of metastases and/or decreased survival. Indeed, in 1991 my colleagues and I reported a statistically significant association between greater incidence of metastases in patients with breast carcinoma and increasing iMVD. Microvessel density was measured with a light microscope in a single area of invasive tumor (200x field or 0.74 mm2) representative of the highest microvessel density (neovascular “hot spot”). This was done after endothelial cells, lining the microvessels, had been highlighted with anti-factor VIII-related antigen/von Willebrand's factor (F8RA/vWF). Subsequent studies by other investigators, using either anti-F8RA/vWF or other relatively vessel-specific reagents such as anti-CD31, have shown that the association of greater tumor aggressiveness with increasing iMVD exists not only in breast carcinoma, but also in other solid tumors. This article reviews the methods of highlighting intratumoral vessels and describes the techniques for counting these vessels for assessing iMVD.
695 citations
TL;DR: Strategies aimed at antagonizing VEGF may form the basis for an effective treatment of tumors and retinopathies, as V EGF-induced angiogenesis is sufficient to achieve a therapeutic endpoint in models of coronary or limb ischemia.
Abstract: Vascular endothelial growth factor (VEGF) is a diffusible endothelial cell-specific mitogen and angiogenic factor that can also increase vascular permeability. By alternative splicing of mRNA, VEGF may exist as one of four different isoforms that have similar biological activities but differ markedly in targeting and bioavailability. The VEGF receptors are specifically expressed in the cell surface of vascular endothelial cells. Recent studies point to VEGF as a major regulator of physiological angiogenesis, such as developmental and reproductive angiogenesis. Furthermore, VEGF appears to be a crucial mediator of blood vessel growth associated with tumors and proliferative retinopathies. The VEGF mRNA is up-regulated in the majority of human tumors and the VEGF protein is increased in the aqueous and vitreous humors of patients with proliferative retinopathies. Anti-VEGF antibodies have the ability to suppress the growth of a variety of tumor cell lines in nude mice and also can inhibit angiogenesis in animal models of intraocular neovascularization. Therefore, strategies aimed at antagonizing VEGF may form the basis for an effective treatment of tumors and retinopathies. Furthermore, VEGF-induced angiogenesis is sufficient to achieve a therapeutic endpoint in models of coronary or limb ischemia.
449 citations
TL;DR: This review summarizes current work on heterodimerization and attempts to predict the consequences for downstream signaling of the EGF receptor family.
Abstract: The EGF receptor (EGFR) and HER2 are members of a growth factor receptor family. Overexpression of either protein in advanced breast cancer correlates with poor prognosis. EGF stimulates growth by binding to EGFR, activating the receptor's intracellular tyrosine kinase. The initial consequence is phosphorylation of specific tyrosine-containing sequences in the receptor's carboxyl terminus. These phosphotyrosines serves as high affinity recognition sites for proteins that, in turn, transmit the growth signal inside the cell. Mechanistic studies suggest that EGF binds to a single EGFR, triggering dimerization with another like receptor molecule. This dimerization is thought to initiate the tyrosine kinase activation. The EGF receptor family was recently expanded with the sequencing of HER3 and HER4. Each of the four family members was postulated to regulate a unique growth or differentiation signaling repertoire when activated by a receptor-specific ligand. However, new data from numerous laboratories suggest that EGFR family members may play a complex and ultimately more flexible role in signaling by forming heterodimers between family members, e.g. EGFR:HER2 or HER4:HER2. These heterodimers may form even when only one member of the pair binds its ligand. This review summarizes current work on heterodimerization and attempts to predict the consequences for downstream signaling. In brief, when compared to ligand-dependent receptor homodimers comprised of two proteins with the same internalization sequence and phosphorylated tyrosine residues, heterodimers are likely to: i) expand substrate selection and downstream signaling pathway activation; ii) promote interaction between sets of substrates in the mixed receptor complexes that would not ordinarily be physically juxtaposed; iii) alter the duration of receptor signaling by changing rates of receptor internalization, ligand loss, kinase inactivation, recycling, etc.; and iv) alter rates of receptor and substrate dephosphorylation. In addition to understanding interactions of heterodimers with the internalization machinery, identification of receptor-specific substrates and binding proteins for each EGFR family member will be necessary to explicate the role of heterodimers in growth and differentiation.
407 citations
TL;DR: It was concluded that MVD is a potent prognostic indicator in primary breast cancer and it was suggested that VEGF plays crucial roles in the promotion of angiogenesis in breast cancer.
Abstract: The importance of tumor angiogenesis in the process of tumor growth and progression in solid tumors has been widely accepted. We have investigated the significance of tumor angiogenesis as a prognostic indicator in a retrospective study including 328 primary breast cancer patients. The postoperative survey demonstrated that the microvessel density (MVD) evaluated by immunocytochemical staining for factor VIII-related antigen is a potent prognostic indicator. The relapse-free survival (RFS) rate of patients with over 100 microvessels/mm2 in a microscopic field was significantly worse compared to that of patients with less than 100 microvessels/mm2 (p<0.00001). The significance of MVD was found in both node-negative and node-positve patients (p< 0.005 and p<0.01, respectively). Multivariate analysis confirmed that MVD is an independent prognostic indicator for RFS. In the background factor analysis, MVD was significantly correlated with the number of metastatic nodes (p<0.01). In addition, the immunocytochemical analysis for vascular endothelial growth factor (VEGF) demonstrated a close association between the increase in MVD and the expression of VEGF (p<0.001). VEGF status also was a significant prognostic indicator in univariate analysis for RFS (p<0.01). It was concluded that MVD is a potent prognostic indicator in primary breast cancer. Furthermore, it was also suggested that VEGF plays crucial roles in the promotion of angiogenesis in breast cancer.
370 citations
TL;DR: The integration of epidemiology and molecular biology provides a new strategy to identify additional risk factors for breast cancer and to better understand the role played by traditionally recognized risk factors.
Abstract: The integration of epidemiology and molecular biology provides a new strategy to identify additional risk factors for breast cancer and to better understand the role played by traditionally recognized risk factors. The Carolina Breast Cancer Study (CBCS) is a population-based, case-control study designed to identify causes of breast cancer among Caucasian and African-American women who are residents of a 24-county area of central and eastern North Carolina. Information on established and potential breast cancer risk factors is obtained by personal interviews. Blood samples are collected from all consenting participants. Medical record documentation and paraffin-embedded tumor specimens are obtained for all breast cancer patients. DNA from tumor tissue is tested for a variety of molecular alterations characteristic of breast cancer. Germline DNA from blood lymphocytes is evaluated for presence of alleles increasing susceptibility to breast cancer. Statistical analyses evaluate gene-environment interaction by exploring the associations between environmental/behavioral factors and breast cancer in relation to specific molecular alterations (germline and tumor). Results will help identify high-risk women, clarify causal pathways, and hopefully contribute to the prevention of breast cancer.
222 citations
TL;DR: It is important not to dismiss the Ras pathway in the development of breast cancer merely because of the infrequent detection of mutations inras itself, but rather to consider the influence of aberrations upstream or downstream of Ras and of certain Ras-related proteins in theDevelopment of breast cancers.
Abstract: Althoughras mutations are infrequent (approximately 5%) in breast cancers, there is considerable evidence that suggests that the pathways which Ras services may still be deregulated in breast cancer cells. The recent identification of many of the components of the Ras signal transduction pathway has defined a network of proto-oncogene proteins controlling diverse signaling events that regulate cell growth and differentiation. Consequently, mutations that perturb the function of any one component of this signal pathway may trigger the same oncogenic events as mutation ofras itself. Moreover, several Ras-related proteins have recently been demonstrated to possess the ability to trigger malignant transformation via signaling pathways shared with Ras proteins. Thus, it is possible that the aberrant function of Ras-related proteins may contribute to breast cancer development. Consequently, it is important not to dismiss the Ras pathway in the development of breast cancer merely because of the infrequent detection of mutations inras itself, but rather to consider the influence of aberrations upstream or downstream of Ras and of certain Ras-related proteins in the development of breast cancer. Finally, the critical importance of components upstream and downstream of Ras provides additional targets for rational drug design approaches to block the aberrant function of Ras signaling in human tumors.
209 citations
TL;DR: PUFA's significantly interfere with cell proliferation of breast cancer cells in vitro due to the formation of oxidation products, indicating that there must be other factors involved in the differential metabolism of PUFA's in tumor cells.
Abstract: Epidemiological studies suggest a causal relationship of dietary polyunsaturated fatty acids (PUFA's) with the morbidity and mortality from breast cancer. In order to reveal possible underlying mechanisms of these findings, we studied the influence of n-3 and n-6 PUFA's in comparison to oleic acid on the proliferation of well characterized estrogen dependent (MCF-7, ZR-75, T-47-D) and estrogen independent (MDA-MB-231, HBL-100) breast cancer cells in culture. The cell growth inhibitory effect was related to the formation of lipid peroxidation products. Normal human skin fibroblasts served as a control. In fibroblasts, the addition of 20 micrograms/ml of exogenous fatty acids either had no effect or caused an insignificant increase of proliferation. Similar results were obtained with MCF-7 cells. In all other breast cancer cell types, n-3 long-chain PUFA's, eicosapentaenoic and docosahexaenoic acids, were the most effective fatty acids in arresting the cell growth. Alpha-linolenic and gamma-linolenic acid exerted a variable effect on cell proliferation depending on the cell line investigated. Oleic acid significantly stimulated the proliferation of hormone-independent breast cancer cells while it had no effect on the proliferation of hormone-dependent cells. Viability studies by trypan blue excretion indicated that the arrest in cell growth was not due to major cytotoxic effects. The addition of PUFA's to breast cancer cells caused a significant increase in the formation of conjugated dienes and lipid hydroperoxides in the cellular lipids; their content was significantly correlated with the capacity of arresting cell growth. In contrast, the addition of PUFA's to fibroblasts did not increase lipid hydroperoxide formation. The addition of Vitamin E to cancer cells at a concentration of 10 microM to the PUFA-supplemented medium almost completely restored cell growth. Our data indicate that PUFA's significantly interfere with cell proliferation of breast cancer cells in vitro due to the formation of oxidation products. In addition to that, there must be other factors involved, most probably related to the differential metabolism of PUFA's in tumor cells. Our findings may have some impact on treatment and prevention of breast cancer.
207 citations
TL;DR: In this paper, the authors performed a study on 942 invasive ductal carcinomas treated with primary surgery between 1980 and 1986 in a center and evaluated its expression by immunohistochemistry in paraffin-embedded tissue using a polyclonal antipeptide antibody.
Abstract: To assess the practical prognostic value of c-erbB2, we performed a study on 942 invasive ductal carcinomas treated with primary surgery between 1980 and 1986 in our center. We evaluated its expression by immunohistochemistry in paraffin-embedded tissue using a polyclonal antipeptide antibody. Of 942 tumors, 229 (24%) showed a positive membrane staining. We observed a significant association between c-erbB2 and Scarff-Bloom-Richardson grading (p < 0.0001) and a negative correlation between c-erbB2 and both estrogen and progesterone receptors (p < 0.0001). In our analysis, with respect to overall survival (OS), relapse-free survival (RFS), and metastasis-free survival (MFS), c-erbB2 was statistically significant (p ≤ 0.0001) for the whole group and the node-positive subgroup. In multivariate analysis, c-erbB2 appeared to be an independant variable for RFS and MFS in the node-negative group. However, in our hands, c-erbB2 had a poor prognostic value in comparison with the classical prognostic variables such as histological grade, nodal status (N), hormonal receptor status (estrogen and progesterone receptors), and tumor size, and it did not supersede the classical parameters.
169 citations
TL;DR: It is suggested that signal transduction mediated by thec-erbB-2 tyrosine kinase can partially overcome the estrogen dependence of ER+ breast cancer cells for growth and that overexpression confers a selective advantage to such cells in the absence of estrogen.
Abstract: Ac-erbB-2 expression vector was transfected into the estrogen receptor positive (ER+) MCF-7 human breast cancer cell line to determine if overexpression of this transmembrane tyrosine kinase could increase the malignant phenotype of this cell line. Loss of transfectedc-erbB-2 expression was observed when cells were carried in medium containing estrogen. Homogeneous populations stably overexpressing levels of the 185 kDac-erbB-2 observed in the SKBR-3 a breast cancer cell line which overexpressesc-erbB-2 as a result of gene amplification could be obtained by continually maintaining the transfected cell lines in estrogen-free conditions. Levels of constitutively activatedc-erbB-2 varied among clonal isolates. Whereas some over-expressing lines did acquire the ability to form transient tumor nodules in ovariectomized nude mice without estrogen supplementation, as well as in mice that received the antiestrogen tamoxifen, one cell line that exhibited the highest levels of constitutively activatedc-erbB-2 was able to form static tumors of a larger size under both conditions. This same cell line formed progressively growing tumors in estrogen-supplemented mice that were much larger than observed in mice injected with control cell lines, and also showed reduced sensitivity to antiestrogensin vitro, but it continued to have a low metastatic phenotype. These results suggest that signal transduction mediated by thec-erbB-2 tyrosine kinase can partially overcome the estrogen dependence of ER+ breast cancer cells for growth and thatc-erbB-2 overexpression confers a selective advantage to such cells in the absence of estrogen.
166 citations
TL;DR: Current knowledge about the regulation of the expression of VEGF and its receptors is reviewed, which appears that growth factors, cytokines, and tumor promoters are involved in the control of V EGF-R expression.
Abstract: Vascular endothelial growth factor (VEGF) / vascular permeability factor (VPS) plays a crucial role for the vascularization of tumors including breast cancers. Tumors produce ample amounts of VEGF, which stimulates the proliferation and migration of endothelial cells (ECs), thereby inducing tumor vascularization by a paracrine mechanism. VEGF receptors (VEGF-Rs) are highly expressed by the ECs in tumor blood vessels. VEGF expression can be induced in various cell types by a number of stimuli including hypoxia, differentiation, growth factors and tumor promoters of the phorbol ester class, such as TPA. The VEGF inductive pathways comprise kinases, oncogenes, tumor suppressor genes, and steroid hormone transcription factors, many of which seem to converge on the activator protein (AP-1) transcription factor. Much less is known about the regulation of VEGF-R expression, which is restricted to ECs. This expression is greatly enhanced in diseased tissue such as solid tumors. So far, it appears that growth factors, cytokines, and tumor promoters are involved in the control of VEGF-R expression. Here we review current knowledge about the regulation of the expression of VEGF and its receptors.
154 citations
TL;DR: Progress in this “vascular targeting” approach is reviewed, from the validation of the concept in a mouse model to the characterization of the TEC-11 antibody against endoglin, an endothelial cell proliferation marker that is upregulated on endothelial cells in miscellaneous human solid tumors.
Abstract: An attractive strategy for the therapy of carcinomas and other solid tumors would be to target cytotoxic agents or host immune effectors to the endothelial cells of the tumor vasculature rather than to the tumor cells themselves. The key advantage of this approach is that the endothelial cells are freely accessible through the blood whereas the tumor cells are, for the most part, inaccessible. Also, endothelial cells are similar in different tumors, making it feasible to develop a single reagent for treating numerous types of cancer. In this chapter, we review progress in this “vascular targeting” approach, from the validation of the concept in a mouse model to the characterization of the TEC-11 antibody against endoglin, an endothelial cell proliferation marker that is upregulated on endothelial cells in miscellaneous human solid tumors. In addition, we review other tumor endothelial cell markers that are candidates for vascular targeting in man.
TL;DR: Initial concerns that long-term tamoxifen causes endometrial cancer have been placed in perspective and analyzed by a review of the literature.
Abstract: In 1973, McGuire and Chamness (In: O'Malley BW and Means AR (eds) Receptors for Reproductive Hormones, Plenum Press) summarized their work on the estrogen receptor in animal and human breast tumors, and in so doing described a target for therapeutic intervention. At that time there were no clinically useful antiestrogens, but the subsequent development of tamoxifen for breast cancer therapy has revolutionized the approach to treatment. Long-term adjuvant tamoxifen adjuvant therapy (i.e. greater than one year) has proven efficacy to enhance the survival of breast cancer patients. In addition, because there is an associated 40% decrease in contralateral breast cancer during adjuvant tamoxifen therapy and tamoxifen maintains bone density and reduces fatal myocardial infarction, clinical trials to test the worth of tamoxifen as a preventive for breast cancer in high risk women have started in the United States, United Kingdom, and Italy. Initial concerns that long-term tamoxifen causes endometrial cancer have been placed in perspective and analyzed by a review of the literature. Tamoxifen only doubles the normal risk of detecting endometrial cancer, (i.e. to 2 per 1,000 tamoxifen-treated women per year), and 80% of these cases are early stage, good prognosis disease. Annual gynecological examinations and education are essential to provide reassurance for patients.
TL;DR: CEA and CA 15.3 are useful tools for early diagnosis of metastases, mainly in those patients with ER+ or PR+ tumors and in patients that were negative for these receptors in the primary tumor.
Abstract: To evaluate the utility of CEA and CA 15.3 for early diagnosis of recurrence, serial serum determinations of both antigens were performed in 1023 patients (follow-up: 1–10 years, mean 6.2 years) with primary breast cancer (CA 15.3 in 533 cases) and no evidence of residual disease (NED) after radical treatment (radical mastectomy or simple mastectomy and radiotherapy). 246 patients developed metastases during follow-up. Results: CEA and CA 15.3 were elevated (> 10 ng/ml or > 60 U/ml, respectively) prior to diagnosis in 40% (98/246) and 41% (37/91) of the patients with recurrence, with a lead time of 4.9 ± 2.2 and 4.2 ± 2.3 months, respectively. When patients with locoregional recurrences were excluded, sensitivity improved to 46% (CEA) and 54% (CA 15.3), and to 64% with both tumor markers (CEA and/or CA 15.3). Higher levels of both CEA and CA 15.3 at diagnosis of recurrence, higher sensitivity in early diagnosis of relapse, and a higher lead time were found in ER+ (CEA) or PgR+ patients (CA 15.3) than in those that were negative for these receptors in the primary tumor (p < 0.001). Specificity of the tumor markers was 99% for both CEA (777 NED patients) and for CA 15.3 (444 NED patients), respectively. In conclusion, CEA and CA 15.3 are useful tools for early diagnosis of metastases, mainly in those patients with ER+ or PR+ tumors.
TL;DR: The Save The authors' Sisters Project builds on the roles of 95 “natural helpers” to increase mammography screening among older African American women in a NC county by linking them to women through places and ways that no health professional could begin to acquire.
Abstract: The Save Our Sisters Project builds on the roles of 95 “natural helpers” to increase mammography screening among older African American women in a NC county. Natural helpers are lay people to whom others naturally turn for advice, emotional support, and tangible aid. Findings from 14 focus group interviews showed that older women seek out these individuals when they have a female-specific concern, rather than or before seeking help from professionals. The characteristics of natural helpers, revealed in the findings, were used to identify and recruit them to become trained lay health advisors in breast cancer education. Through the SOS Project, natural helpers provide a community-based system of care and social support that complements the more specialized role of health professionals; linking them to women through places and ways that no health professional could begin to acquire. The three roles of lay health advisors are: (1) to assist individuals in their social networks with needs that are difficult for professionals to address; (2) to negotiate with professionals for support from the health system; and (3) to mobilize the resources of associations in their community to sustain support from the health system.
TL;DR: TNP-470/minocycline administration increased the efficacy of fractionated radiation therapy, especially when used along with a perflubron emulsion oxygen delivery agent/carbogen, and indicates that treatment regimens including therapies directed toward the proliferating normal cells within a tumor mass as well as therapies directed towards the malignant cells can produce improved outcomes.
Abstract: The ability of the antiangiogenic agents TNP-470 and minocycline, singly or in combination, to potentiate the antitumor effects of several cytotoxic therapies was assessed in the murine EMT-6 mammary carcinoma as well as in two drug resistant sublines of that tumor designated EMT-6/CTX and EMT-6/CDDP. The antiangiogenic agents alone or in combination did not alter the growth of the tumors. However, their administration along with cyclophosphamide, CDDP, or thiotepa substantially increased the tumor growth delay produced by these cytotoxic therapies in tumors responsive to the drugs--the increase was about 2-fold for TNP-470 and minocycline together. In drug resistant tumors, treatment with the antiangiogenic agents did not reverse drug resistance but did increase the effect of the cytotoxic drugs. Treatment with TNP-470/minocycline also increased the oxygenation of each of the three tumors. Thus, TNP-470/minocycline administration increased the efficacy of fractionated radiation therapy, especially when used along with a perflubron emulsion oxygen delivery agent/carbogen. These results indicate that treatment regimens including therapies directed toward the proliferating normal cells within a tumor mass as well as therapies directed toward the malignant cells can produce improved outcomes.
TL;DR: The results of this study confirm the prognostic importance on RFS of the variables previously tested, but not of peritumoral lymphatic vessel invasion, and a novel finding is that 67 kDa laminin receptor and the IMD/67 k da laminationin receptor interaction are also significant and independent variables.
Abstract: In the present study we update previous results on the prognostic value of intratumoral microvessel density (IMD), determined immunocytochemically using the monoclonal antibody CD-31 and a standard streptavidin-immunoperoxidase technique, published in theJ Clin Oncol 12:454–466, 1994. This study was undertaken in those 211 node-negative breast cancer (NNBC) cases of that series of which we had pathological material available to determine all the prognostic indicators. The median period of follow-up has been extended to 78 and 80 months for relapse-free survival (RFS) and overall survival (OS), respectively, and new biological indicators (i.e. Ki-67 labeling and 67 kDa laminin receptor expression) were included in the analysis. The main results obtained are:i) a confirmation that IMD is not associated with the other biological markers studied, i.e. expression of p53 protein, c-erbB-2 protein, 67 kDa laminin receptor, and cell kinetics; IMD was weakly associated only with histological grade (p=0.053);ii) IMD remains a highly significant prognostic factor for RFS and OS (p<0.0001 and p=0.018, respectively) in univariate analysis;iii) in multivariate analysis on RFS, IMD (likelihood ratio test (LRT)=30.16; p<0.0001), 67 kDa laminin receptor (LRT=9.80; p=0.0017), the IMD/67 kDa laminin receptor interaction (LRT=8.62; p=0.0033), tumor size (LRT=8.56; p=0.0034), and p53 protein (LRT=4.96; p=0.025) are significant and independent prognostic indicators. For OS, only tumor size (LRT=8.34; p=0.0038), menopausal status (LRT=5.16; p=0.023), p53 protein (LRT=4.37; p=0.036), and IMD (LRT=4.05; p=0.044) retain a significant and independent prognostic value. The results of this study confirm the prognostic importance on RFS of the variables previously tested, but not of peritumoral lymphatic vessel invasion. A novel finding is that 67 kDa laminin receptor and the IMD/67 kDa laminin receptor interaction are also significant and independent variables. For OS, the results confirm that both IMD and tumor size are significant and independent variables. With prolonged follow-up the novel finding that emerges is the prognostic importance of menopausal status and p53 protein. This new information could be useful for a more accurate selection of high-risk NNBC patients who require careful follow-up and may benefit from adjuvant therapy.
TL;DR: In the BT549 human breast carcinoma cell line, the reintroduction of a wild type p53 tumor suppressor gene resulted in the stimulation of the secretion of an inhibitor ofAngiogenesis, thrombospondin-1, and as a result the cells lost their angiogenic phenotype and became able to suppress angiogenesis induced by the parental tumor line.
Abstract: Fifteen different natural inhibitors of angiogenesis have now been identified that are produced by mammalian cells and are able to block in vivo neovascularization. The majority of these are able to inhibit endothelial cell activities in vitro and all those tested have demonstrated significant antitumor activity. Most normal cells produce inhibitors of neovascularization that must be downregulated before the cells can develop into angiogenic, malignant tumors. In several cases the production of inhibitors ceases when tumor suppressor genes are inactivated. In the BT549 human breast carcinoma cell line, the reintroduction of a wild type p53 tumor suppressor gene resulted in the stimulation of the secretion of an inhibitor of angiogenesis, thrombospondin-1, and as a result the cells lost their angiogenic phenotype and became able to suppress angiogenesis induced by the parental tumor line. These results provide a new example of tumor suppressor gene control of a natural inhibitor of angiogenesis and add support to the concept that thrombospondin loss may play an important role in the development of some human breast cancers.
TL;DR: The Netherlands Cohort Study on diet and cancer found no association between the consumption of onions or leeks, or garlic supplement use, and the incidence of female breast carcinoma.
Abstract: The risk of female breast carcinoma in relation to onion and leek consumption and the use of garlic supplements was evaluated in the Netherlands Cohort Study on diet and cancer. Onions, leeks, and garlic contain specific compounds which might act as antimutagens. Animal experiments also suggest a possible role for these compounds in inhibition of mammary carcinogenesis. The Netherlands Cohort Study was started in 1986 among 120,852 Dutch men and women, aged 55-69 years, with collecting information on usual diet and important lifestyle characteristics. After 3.3 years of follow-up, 469 incident female breast carcinoma cases and 1713 female members of a randomly sampled control subcohort were available for analysis. Intake of onions or leeks was not associated with breast carcinoma risk after controlling for dietary and nondietary risk factors: the rate ratios in the highest intake categories were 0.95 (95% confidence interval 0.61–1.47) and 1.08 (95% confidence interval 0.79–1.48), respectively, compared with the lowest intake categories. The tests for trend in the rate ratios were neither significant. Garlic supplement use was also not associated with breast carcinoma incidence (rate ratio = 0.87, 95% confidence interval 0.58–1.31). In conclusion, we found no association between the consumption of onions or leeks, or garlic supplement use, and the incidence of female breast carcinoma.
TL;DR: There was no significant association between AR, HRG, and CR-1 expression and nodal status, EGF receptor, or c-erbB-2 protooncogene expression in these tumors, however, a significant associationBetween AR expression and estrogen receptor positivity was observed.
Abstract: The expression of amphiregulin (AR), heregulin (HRG), and cripto-1 (CR-1) mRNA transcripts was assessed in 60 human primary breast carcinoma. AR and HRG transcripts were expressed respectively in 58% and 25% of the carcinomas as measured by Northern blot analysis. CR-1 mRNA was found in 77% of the carcinomas using Reverse Transcriptase-PCR analysis. Coexpression of two or three of these peptides was observed in several specimens. There was no significant association between AR, HRG, and CR-1 expression and nodal status, EGF receptor, or c-erbB-2 protooncogene expression in these tumors. However, a significant association between AR expression and estrogen receptor positivity was observed.
TL;DR: This study shows that potent aromatase inhibition with 4-OHA is effective in women with advanced BC who have already been treated with a less potent arom atase inhibitor, and suggests that relative changes in oestrogen levels may be more important than absolute levels.
Abstract: One hundred and twelve post menopausal or post oophorectomy women with advanced breast cancer (BC) who had all previously had aminoglutethimide (AG) were treated with the potent aromatase inhibitor 4-hydroxy androstenedione (4-OHA). Twenty three women (21%) had a partial response to 4-OHA while another twenty five patients (22%) had stabilization of previously progressing disease. Patients responded to 4-OHA both after previously responding to then relapsing on, and after failing to respond to aminoglutethimide. Toxicity was minimal. This study shows that potent aromatase inhibition with 4-OHA is effective in women with advanced BC who have already been treated with a less potent aromatase inhibitor, and suggests that relative changes in oestrogen levels may be more important than absolute levels.
TL;DR: How an understanding of the process of angiogenesis may contribute to improved management of patients with breast cancer is discussed.
Abstract: The diagnosis and treatment of patients with breast cancer is beginning to be influenced by new ideas and discoveries emerging from the field of angiogenesis research. This field, pursued in the laboratory for more than 20 years, has in the past 5 years generated clinical applications. Some of these applications have begun to change current thinking about cancer patients and especially about those with breast cancer. I here discuss how an understanding of the process of angiogenesis may contribute to improved management of patients with breast cancer.
TL;DR: A sensitive enzyme-linked immunosorbent assay, with polyclonal catching antibodies and three monoclonal detecting antibodies, is developed which appears suitable for studies of the potential prognostic value of uPAR in this disease.
Abstract: Urokinase plasminogen activator (uPA) is a proteolytic enzyme involved in degradation of the extracellular matrix during cancer invasion. The levels of uPA and its inhibitor PAI-1 in tumor extracts have previously been demonstrated to be of prognostic value in breast cancer as well as other types of cancer. We have previously characterized a specific cell surface receptor for uPA (uPAR) which strongly enhances the catalytic activity of uPA and is expressed during mammary cancer invasion. In order to quantitate uPAR in breast cancer tissue, we have now developed a sensitive enzyme-linked immunosorbent assay (ELISA), with polyclonal catching antibodies and three monoclonal detecting antibodies. The detection limit of the assay is approximately 0.16 fmol of uPAR in a volume of 100 µl (1.6 pM). There is a linear relationship between signal and uPAR concentration up to at least 6.6 fmol per 100 µl (66 pM). Both free uPAR and uPAR in complex with uPA is detected. The recovery of an internal uPAR standard in breast cancer tissue extracts is above 87%. The intra-assay and inter-assay variation coefficients are 7% and 13%. In order to find a suitable buffer for extraction of various components of the uPA-system from breast cancer tissue, we tested buffers which previously have been used for optimal extraction of estrogen receptor (A), uPA (B), and uPAR (C). Buffer A and B extracted approximately 30% and 50%, respectively, of the amount of uPAR extracted with buffer C. Extracts of samples of breast cancer tissue from 94 patients all contained uPAR in amounts above the detection limit of the present assay, which appears suitable for studies of the potential prognostic value of uPAR in this disease. Significant correlations were found between uPAR, uPA and PAI-1 tumor levels.
TL;DR: Amphiregulin is an epidermal growth factor (EGF)-related peptide that operates exclusively through the EGF receptor and that can bind to heparin that possesses nuclear localization sequences in the extended NH2-terminal region suggesting an additional intracellular site of action.
Abstract: Amphiregulin (AR) is an epidermal growth factor (EGF)-related peptide that operates exclusively through the EGF receptor and that can bind to heparin. AR also possesses nuclear localization sequences in the extended NH2-terminal region suggesting an additional intracellular site of action. AR mRNA and protein expression have been detected in primary human mammary epithelial cell strains, nontransformed human mammary epithelial cell lines, several human breast cancer cell lines, and primary human breast carcinomas. The frequency and levels of AR protein expression are generally higher in invasive breast carcinomas than in ductal carcinomasin situ or in normal, noninvolved mammary epithelium. In addition, AR can function as an autocrine and/or juxtacrine growth factor in human mammary epithelial cells that have been transformed by an activated c-Ha-ras proto-oncogene or by overexpression of c-erb B-2. AR expression is also enhanced by mammotrophic hormones such as estrogens and other growth factors such as EGF.
TL;DR: A physical map of the amplified DNA is constructed and the extent and frequency of amplification across the region is compared and cyclin D1 remains the strongest candidate for the key oncogene on the amplicon and the functional consequences of its over-expression are investigated.
Abstract: One in six primary human breast cancers has DNA amplification centered on the cyclin D1 gene (CCND1) on chromosome 11q13. This genetic abnormality is preferentially associated with estrogen-receptor positive tumors and may define a sub-class of patients with an adverse prognosis. AlthoughCCND1 has the credentials of a cellular oncogene, being a target for chromosomal translocation and retroviral integration, the 11q13 amplicon encompasses several other markers andCCND1 is not the only candidate for the key gene on the amplified DNA. To assess their relative importance, we have constructed a physical map of the amplified DNA and compared the extent and frequency of amplification across the region. Since it is likely that the gene providing the selective force for amplification will be expressed at elevated levels, we have also examined expression of both RNA and protein. By these criteria, cyclin D1 remains the strongest candidate for the key oncogene on the amplicon and we are currently investigating the functional consequences of its over-expression.
TL;DR: Women with a menarcheal age of 10 or 11 years showed a 2.2 times higher risk for breast cancer compared to women who had their first menstrual period at 12 years of age or older.
Abstract: Early age at menarche is a known risk factor for breast cancer, some inconsistency in the literature not withstanding. Relative risks for an early menarcheal onset as compared to a late onset vary from 1.0 to 1.9. To avoid (residual) confounding by parity-related factors a case-control study was conducted among nulliparous women. 135 cases and 540 controls were selected from two population-based screening projects for breast cancer in The Netherlands. Four controls were matched to each case for year of birth, for screening-centre, and for number of screening examinations. Women with a menarcheal age of 10 or 11 years showed a 2.2 times (95% confidence interval: 1.2-4.0) higher risk for breast cancer compared to women who had their first menstrual period at 12 years of age or older.
TL;DR: The genesis of this comprehensive community intervention model is described, highlighting the behavioral science constructs, health education principles, and theories of behavioral and organizational change that form its conceptual foundation.
Abstract: Breast cancer screening programs do not reach all women at the same rate Screening mammography use varies according to sociodemographic characteristics; mammography utilization is highest among women in their fifties but then decreases with age In North Carolina, breast cancer is a particular burden for Black and lower-income women Black women are more likely to be diagnosed with late stage disease, and their rate of breast cancer mortality is higher than it is for White women even though the incidence in White women is greater Older, Black, and low-income women are less likely to obtain screening by mammography and clinical breast examination The Black-White gap is even more pronounced among rural women, in part because they are more likely to be poor The North Carolina Breast Cancer Screening Program (NC-BCSP) was established to increase the rate of regular mammography screening by an absolute 20% in 3 years among older Black women ages 50 and older in five rural counties in the eastern part of the state In this paper, we describe the genesis of this comprehensive community intervention model, highlighting the behavioral science constructs, health education principles, and theories of behavioral and organizational change that form its conceptual foundation NC-BCSP's theoretical foundations include the social ecological perspective, the PRECEDE model of health promotion, the Health Belief Model of individual change, and the “stages of change” transtheoretical model We also review the experiences and lessons learned from two previous outreach initiatives in North Carolina that provided valuable “lessons” in the development of the NC-BCSP intervention model In the second half of the paper, we describe the actual NC-BCSP interventions, activities, and evaluation tools, citing specific examples of how the underlying theories are implemented NC-BCSP's goal goes beyond individual behavior change to raise low mammography screening rates among Black women in rural North Carolina Its ultimate objective is to create linkages across agencies, and between agencies and communities, that will endure after the research project ends
TL;DR: The rapid reporting procedures are straightforward, cost-effective, and greatly benefit the objectives of tissue collection and interviews with the cases, and their potential impact for population-based research is described.
Abstract: To support a study of genetic risk factors for breast cancer, the North Carolina Central Cancer Registry has implemented a rapid reporting procedure for hospitals in the study area. This system permits the identification of newly diagnosed breast cancer cases within a very short time period (less than one month). The procedures are straightforward, cost-effective, and greatly benefit the objectives of tissue collection and interviews with the cases. This article describes the rapid reporting procedures and their potential impact for population-based research. For the objective of making generalizable risk statements, the necessity of population-based research is stressed; participation with central cancer registries is endorsed for this and other molecular epidemiologic applications.
TL;DR: Results indicate that the expression of the CD44 variants is upregulated in mammary carcinomas and is closely linked to tumor anaplasia.
Abstract: Splice variants of CD44 expressed in a metastasizing cell line derived from a rat pancreatic adenocarcinoma have been shown recently to confer metastatic potential onto non-metastasizing rat pancreatic carcinoma and sarcoma cell lines Homologues of these variants have also been detected in a variety of human malignancies Using antibodies raised against a bacterially expressed fusion protein containing variant CD44 sequences, we have explored the expression of variant CD44 glycoproteins on tumors of the female breast The material examined included normal tissue, hyperplastic lesions, 103 primary invasive mammary carcinomas, 10in situ carcinomas, 12 local recurrences and 18 lymph node metastases Using a polyclonal serum directed against several variant CD44 epitopes, normal mammary epithelia as well as ductal hyperplasias were negative for these splice variants, while the variant CD44 epitopes were detectable in all but six of the primary invasive carcinomas From the reaction with various monoclonal antibodies and polyclonal sera specific for individual epitopes it is obvious that the tumors predominantly express CD44 variants encoded by exons v5 to v7 Interestingly, all investigated lymph node metastases reacted positively with the variant-specific antibodies, in contrast to primary tumors which reacted in 54% to 86% of the cases, depending on the antibody used Statistical analysis revealed a significant correlation between expression of variant exons v3/v4 and v6 and increased tumor grade (p = 0001 and p < 005, respectively; Fisher's exact test) Exon v6 is carried by the variants which confer metastatic capability in the rat These results indicate that the expression of the CD44 variants is upregulated in mammary carcinomas and is closely linked to tumor anaplasia
TL;DR: Further experiments are described to characterize the activity and biological consequences of expression of this variant ER in human breast cancer cells, and the implications with regard to the treatment of tamoxifen-resistant disease are discussed.
Abstract: Measurements of the estrogen receptor (ER) and the estrogen-induced progesterone receptor (PgR) are used by most clinicians as indicators of both overall prognosis and likelihood of response to endocrine therapy. Patients with ER+/PgR+ tumors have the highest likelihood of response; conversely, patients with ER-/PgR- tumors have the lowest likelihood of response. Unfortunately, most patients treated successfully with endocrine therapy eventually develop endocrine-resistant disease recurrence. In an effort to study potential mechanisms of endocrine resistance, we have studied discordant ER-/PgR+ tumors, in which the normally estrogen-regulated PgR gene is induced in the apparent absence of ER. Our laboratory has previously cloned, from ER-/PgR+ tumors, a variant ER mRNA precisely missing the sequence corresponding to ER exon 5, and has demonstrated that the truncated protein product translated from this variant RNA is capable of constitutively inducing the expression of an estrogen-responsive reporter gene in a yeast expression vector system (Fuqua et al, Cancer Res 51:105-109, 1991). In the present report we describe further experiments to characterize the activity and biological consequences of expression of this variant ER in human breast cancer cells. We have stably transfected MCF-7 human breast cancer cells with a mammalian expression vector for the exon 5 deletion variant ER. These transfected cells produce a truncated ER protein of the expected 40 kDa size. Cells expressing the exon 5 ER deletion variant constitutively express PgR, and manifest increased anchorage-independent colony formation in the absence of estrogen. Furthermore, the anchorage-dependent growth of these cells was not inhibited by the triphenylethylene antiestrogens tamoxifen or 4-hydroxytamoxifen, unlike MCF-7 cells transfected with a control plasmid, which were growth inhibited by both of these compounds. Interestingly, the pure antiestrogen ICI 164,384 did inhibit the growth of exon 5 ER deletion variant-expressing transfectants. The implications of these results with regard to the treatment of tamoxifen-resistant disease are discussed.
TL;DR: The spectrum of protein kinases expressed in human breast cancer cells is studied and fourprotein kinases with potentially important functions in breast cancer are identified:rak (src-related), TK5 (which the authors now designate JAK3), the focal adhesion kinase (FAK), and STK1 (human M015/CAK).
Abstract: The family of protein kinases includes many oncogenes and growth factor receptors, many of which have been linked to the pathogenesis and progression of cancer. Protein tyrosine kinases such as HER-2/c-erbB-2 and the epidermal growth factor receptor (EGFR) have been linked specifically to breast cancer, and perturbations of HER-2 affect response to chemotherapy. We have reviewed the biology of protein kinases in human breast cancer, as well as their translational applications to breast cancer patients. We have studied the spectrum of protein kinases expressed in human breast cancer cells and have identified four protein kinases with potentially important functions in breast cancer:rak (src-related), TK5 (which we now designate JAK3), the focal adhesion kinase (FAK), and STK1 (human M015/CAK). We describe the potential significance of these genes in breast cancer, as well as our methodology for identifying and characterizing novel genes in breast cancer.