Proteomics in mammary cancer research Fink-Retter, A.; Gschwantler-Kaulich, D.; Singer, C. ...
Journal of clinical oncology,
05/2008, Letnik:
26, Številka:
15_suppl
Journal Article
Abstract
Background:BRCA-1/2 germline mutations are responsible for early onset breast cancer with poor outcome. The underlying causes of the particularly malignant phenotype are not completely ...understood, but mammary stem cells appear to have a key role in this process.Materials and Methods: We have investigated the presence of mammary stem/progenitor cells in normal tissues and in tumor tissues obtained from women with and without BRCA1/2 germline mutations by utilizing ALDH-1 immunohistochemistry.Results: Isolated ALDH-1 positive cells were found in 15/18 (64%) of breast cancer samples from women with BRCA 1 or 2 mutations and in 33 /51 (65%) of matched sporadic breast cancer cases (p=0.5949, Chi Square test). While mammary stem cells were also detected in non-malignant breast lesions, only 41% of the tissues contained ALDH-1 positive cells (p=0.0371, Chi Square test). In patients with BRCA germline mutations ALDH-1 positive cells were more common in p53 positive (p=0.0028, Chi Square test) tumors, in high grade (p=0.0796), and in larger tumors (p=0.0604), while no such association was seen in sporadic cancer cases. In our patients, the expression of ALDH-1 positive cells in breast cancer was neither associated with disease-free and overall survival, nor time to metastasis.Conclusion: Breast cancers from BRCA mutation carriers do not harbour more ALHD-1 positive cells than sporadic tumors, and their more aggressive phenotype can thus not be explained by an increased stem cell pool. The presence of ALDH-1 in normal breast tissue suggests that additional factors determine the biological behaviour of mammary stem cells.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1156.
Abstract only
e22035
Background: HER-2 amplification and consecutive overexpression is a predictor for poor prognosis in breast cancer patients. In addition, incomplete resection of HER2 ...overexpressing tumors leads to increased proliferation of residual breast cancer cells. While the local release of cytokines is thought to be responsible for the malignant behaviour of remaining tumor tissue, the exact mechanism is still unknown. Methods: We have analyzed EGFR, activated (p)EGFR, and activated (p)HER2 protein expression in HER2 overexpressing and in non-HER2 overexpressing tumors from patients who underwent breast surgery and consecutive reexcision for involved margins, and compared expression levels by IHC. Results: While overall HER2 protein expression in the initial and the reexcised sample were comparable, we observed an increase in pHER2 in DCIS in both, HER2 overexpressing (16/21 vs 24/24; p=0.018, Chi Square test) and non-HER2 overexpressing tumors (3/28 vs 5/12; p=0.025, Chi Square test). pHER2 was not increased in invasive tumors, regardless on whether the samples had been taken from a HER2 overexpressing (9/25 vs 6/17; p=0.261, Chi Square test), or a non-HER2 overexpressing tumor (1/27 vs 0/8; p=0.581, Chi Square test). EGFR expression was only detected in 1/47 HER2 overexpressing primary tumors and 2/48 non-HER2 overexpressing tumors, and was undetectable in reexcised specimen. Conclusions: Taken together, we have demonstrated an increase in HER2 receptor activation in incompletely resected preinvasive breast cancer. We hypothesize that receptor phosphorylation is caused by growth factor stimulation in response to intraoperative tissue damage, and perioperative inhibition of specific cytokines could become a promising therapeutic strategy.
No significant financial relationships to disclose.
Abstract only
21138
Background: Invasive growth requires degradation of extracellular matrix. A number of Zn
2+
-dependent matrix metalloproteinases (MMPs) is associated with this process and leads ...to local invasion and metastasis in malignant breast tumors. Especially the expression of MMP-2 and MMP-9 has been associated with high potential of metastasis in breast cancer. Methods: We determined the expression patterns of epithelial (E) and stromal (S) MMP-1, MMP-2, MMP-9 and MMP-11 by immunohistochemistry in tissue arrays, containing 50 paraffin-embedded sets of tissues obtained from the malignant tumor of the breast, and 50 paraffin-embedded sets of tissues from metastatic lymph nodes (purchased from Biomax, Biomax Inc, Rockville, MD). Results: MMP2-S and MMP9-S protein expression was significantly higher in lymph node tumor tissue when compared to breast tumor tissue (10% vs. 2%; p=0.005; 78.3% vs. 94.8%, p=0.01 Chi Square test, respectively). MMP9-E showed a borderline significance in lymph node tumor tissue (92.6% vs. 73.5%; p=0.05 Chi Square test). While in breast tumor tissue significant correlations were observed between all MMPs except MMP2-S, these associations were less pronounced in lymph node tumor tissue. Conclusions: We suggest that the expression of MMP-2 and MMP-9 in breast cancer tissue is associated with a high invasive and metastatic potential. This might be confirmed by our finding that MMP2-S, MMP9-S and MMP9-E are increased expressed in metastatic lymph node tissue. This is in line with other studies which showed that MMP-2 and MMP-9 expression in primary breast cancer tissue samples was associated with breast cancer progression and invasion.
No significant financial relationships to disclose.
Abstract only
11098
Background: Neoadjuvant chemotherapy is the treatment of choice for locally-advanced breast cancer and leads to down staging and improved BCT rates. While its efficacy is well ...established, considerably less is known about the most effective regimen. Methods: We have performed a retrospective analysis of 132 breast cancer patients who had undergone neoadjuvant chemotherapy at our institution. Patients had either received a) anthracyclines (“A”, n=35), b) anthracyclines and taxanes (“AT”, n=55), or c) neither of the two compounds (“NoA/T”, n=42). Clinical response, pathological response and survival were evaluated in each arm. Results: While all three regimen resulted in significant tumor regression, AT was most effective with a mean tumor shrinkage of 39% (ultrasound) and 41% (mammography) (Kruskal-Wallis, p=0.004, and p=0.027). Breast conservation was achieved in 75% by AT, in 49% by A, and in 19% by NoA/T (Kruskal-Wallis, p<0.001). The treatment groups did not differ in respect to pCR (χ
2
-test, p=0.068), although higher cumulative anthracycline doses were predictive of pCR in multivariate analyses (p=0.022). While the mammographic and not the ultrasound-determined tumor diameter determined whether a woman underwent BCT, only an ultrasound-determined size reduction was predictive for DFS and OS (log rank, p=0.0093, and p=0.044, respectively). Other parameters that affected BCT rates were age (p= 0.003), year of diagnosis (p=<0.001), presence of multifocal disease (p= 0.032) and the cumulative anthracycline dose (p= <0.001). Conclusions: While the combination of anthracyclines and taxanes is most effective in achieving clinical remission and BCT, the cumulative anthracycline dose appears most important for achieving pCR.
No significant financial relationships to disclose.
Abstract only
1519
Objective: Breast cysts are the most common cause of benign breast masses. Simple breast cysts do not need further evaluation, but complex breast cysts require additional ...assessment due to the potential presence of malignancy. However these complex cysts have rarely been examined and quantified according the associated cancer detection rate. Our study is the first investigation that evaluates the malignancy rate of complex breast cysts identified by histo-pathological results. Material and Methods: Imaging findings of complex cysts were correlated retrospectively with clinical and pathologic outcomes. Results: 150 complex breast cysts were found in 132 women. We detected a high malignancy rate of 14%. Sonographic criteria of a complex cyst such as thick cyst wall (p=0.0006), lobulation (p=0.01) or hyperechogenicity (p=0.04) were predictive of neoplasm. Two or more criteria combined were associated with a 13.6 - fold higher risk of malignancy (p<0.0001). Menopause status, family history or personal history of breast cancer did not influence the detection rate of neoplasm. Conclusion: Based on our results we raise the issue for the need of surgical intervention, compared to observation by ultrasound of complex breast cysts to prevent a missed or delayed diagnosis of breast cancer.
No significant financial relationships to disclose.
Abstract only
21075
Background: Breast cancer is chatacterized by malignant transformation of epithelial cells, but stromal cells also play an important role in tumorigenesis. While tumoral ...fibroblasts display unique phenotypical properties, it is unclear whether they also represent are a specific subpopulation. Materials and Methods: Stromal fibroblasts deriving from malignant tissue of 10 women with invasive breast cancer, and from normal breast tissue of 10 women with benign breast disorders, were subjected to differential complementary DNA Microarray Analysis by using a 2400 gene cDNA array. Gene expression results were validated by real-time PCR and by immunohistochemistry. Results: In a cDNA Array that allows to analyze the differential gene expression of more than 2400 genes, the mRNA expression of 135 genes were increased more than 2 fold in fibroblasts from malignant breast tumors. The majority of these genes encode tumor-promoting cytokines, transcription factors and cell-matrix associated proteins. The mRNA expression of 110 genes decreased to less than 0.5 fold. The remaining 2155 genes were not significantly altered. Immunohistochemistry for selected proteins performed on biopsies from breast cancer and normal breast tissues confirmed the clinical relevance of our findings. Conclusion: Breast cancer-derived stromal fibroblasts show a distinctive gene expression pattern that differentiates them from normal breast stroma. Our observation of increased expression of tumor promotion-associated genes even in the absence of adjacent malignant epithelium suggests that tumor stroma is comprised of a fibroblastic subpopulation that provides for a microenvironment which supports tumor growth and invasion.
No significant financial relationships to disclose.
Abstract only
20041
Background: Overexpression of HER family members is a well-established prognositc factor and identifies potential targets for antibody-based receptor blocking strategies. While ...several studies have analyzed the expression of HER-2 and other HER-family members in malignant tumors, considerably less is known about their expression and activation in non-involved breast tissue from breast cancer patients. Methods: We have therefore investigated the differential expression of EGFR, HER-2 and their tyrosinekinase activated forms (ptyr-1248 HER-2 and ptyr-845 EGFR) by using immunohistochemistry (IHC) in 64 tumor specimens containing malignant epithelium (a), non-malignant tissue located at the peritumoral margin (b), and univolved breast tissue obtained at a distance of at least more than 5 cm from the malignant tumor (c). Results: We found significantly higher HER-2 protein expression levels in malignant epithelium than in non-malignant epithelium (p = 0.000004, Fisher’s Exact Test). Stromal HER-2 was absent in any of the tissues investigated. Epithelial EGFR expression did not differ between the three tissue types, but stromal EGFR protein was significantly more common in peritumoral and non-involved distant tissues when compared to tumor tissues (p = 0.008, Fisher’s Exact Test). We only found one case of intratumoral epithelial ptyr-1248 HER-2 expression, and interestingley two cases in peritumoral and peripheral normal tissue. Furthermore, we did not observe ptyr-845 EGFR in any of the samples analyzed.We found a significant overall correlation between epithelial and stromal EGFR expression (r = 0.442; p < 0.0001; Spearman’s Rho). Furthermore, we found a significant overall correlation between stromal EGFR expression and normal tissue type (r = 0.170; p < 0.02; Spearman’s Rho), and an inverse correlation between epithelial HER-2 and normal tissue type (r = 0.492; p < 0.0001; Spearman’s Rho). Conclusion: We have found a differential expression pattern of EGFR, HER-2, and activated HER-2 that is dependent on the spatial relation to a malignant tumor. Our observation of decreased intratumoral EGFR expression and the absence of activated EGFR suggest that, in contrast to HER-2, EGFR inhibition might not be an ideal target for antibody therapy.
No significant financial relationships to disclose.
Abstract only
10105
Background: The suppression of local estrogens levels is of key importance in the treatment of ER positive breast cancer. Essentially all endocrine strategies act by either ...suppressing estrogen formation or by competitively inhibiting receptor binding in tumor cells. Nevertheless, little is still known about the local expression of aromatase and sultotransferase which are key modulators of intra-tumoral estrogen levels. Methods: We have performed immunohistochemostry to investigate the expression of aromatase and sulfotransferase in 42 samples obtained directly from malignant breast tumors, and compared it to biopsies obtained from uninvolved tissue in the vicinity of the invasion front, and to distant breast tissue. Results: We found that aromatase was equally detectable in both tumor epithelial and stroma, but was mostly epithelial in non-malignant tissues (p=0.00008, Fisher’s Exact Test). Also, aromatase protein expression was significantly more common in tumoral stroma when compared to peri-tumoral and distant breast stroma (p=0.00005, and p<0.00001, respectively). With the notable exception of cystosarcoma phylloides, sulfotransferase protein was only detectable in epithelial tissues, regardless of the location within the diseased breast. Epithelial sulfotransferase was, however, correlated with epithelial aromatase (r=0.35461, p=0.0009, Spearman’s Rho test) and with the epithelial ER status (r=0.29313, p=0.005). Conclusions: Taken together, we have demonstrated a differential aromatase and sulfotransferase protein expression pattern that is dependent of the spacial relation to a malignant breast tumor. Our results indicate a net increase in intra-tumoral active estrogen levels through increased stromal aromatization, while physiological local inactivation by sulfotransferase activity remains essentially unchanged.
No significant financial relationships to disclose.
Overexpression of HER family members is a well established prognostic factor and identifies potential targets for antibody-based receptor blocking strategies. While several studies have analyzed the ...expression of HER2 and other HER-family members in malignant tumors, considerably less is known about their expression and activation in non-involved breast tissue from breast cancer patients. We have therefore investigated the differential expression of EGFR, HER2, and their tyrosine-kinase activated forms (ptyr-1248 Her-2 and ptyr-845 EGFR) in 63 tumor specimen containing: a) malignant epithelium, b) in non-malignant tissue located at the peritumoral margin, and c) in uninvolved breast tissue obtained from tissue distant from the tumor. Using immunohistochemistry (IHC), we found significantly higher HER2 protein expression levels in malignant epithelium than in marginal and peripheral non-malignant epithelium (p=1.3 x 10(-10) Fisher's exact test). Epithelial EGFR expression did not differ between the three tissue types, but stromal EGFR protein was significantly more common in marginal and peripheral tissues when compared to tumor tissues (p=0.008, Fisher's exact test). When analyzing activated receptor forms, we found epithelial ptyr-1248 HER2 expression in one tumoral, one marginal and one peripheral sample. We did not observe ptyr-845 EGFR in any of the samples analyzed. We found a significant overall correlation between epithelial and stromal EGFR expression (r=0.442; p<0.0001; Spearman's Rho), and between stromal EGFR expression and normal tissue type (r=0.170; p<0.02; Spearman's Rho). Epithelial HER2 expression and normal tissue type (r=0.492; p<0.0001; Spearman's Rho) were inversely correlated. Taken together, we have observed a differential expression pattern of EGFR, HER2, and activated HER2 that is dependent on the spatial relation to a malignant tumor. Our findings of decreased intratumoral EGFR expression and the absence of activated EGFR suggests that, in contrast to HER2, EGFR inhibition might not be an ideal target for antibody therapy.
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