Imaging of metastatic lymph nodes by X-ray phase-contrast micro-tomography.

Invasive cancer causes a change in density in the affected tissue, which can be visualized by x-ray phase-contrast tomography. However, the diagnostic value of this method has so far not been investigated in detail. Therefore, the purpose of this study was, in a blinded manner, to investigate whether malignancy could be revealed by non-invasive x-ray phase-contrast tomography in lymph nodes from breast cancer patients. Seventeen formalin-fixed paraffin-embedded lymph nodes from 10 female patients (age range 37-83 years) diagnosed with invasive ductal carcinomas were analyzed by X-ray phase-contrast tomography. Ten lymph nodes had metastatic deposits and 7 were benign. The phase-contrast images were analyzed according to standards for conventional CT images looking for characteristics usually only visible by pathological examinations. Histopathology was used as reference. The result of this study was that the diagnostic sensitivity of the image analysis for detecting malignancy was 100% and the specificity was 87%. The positive predictive value was 91% for detecting malignancy and the negative predictive value was 100%. We conclude that x-ray phase-contrast imaging can accurately detect density variations to obtain information regarding lymph node involvement previously inaccessible with standard absorption x-ray imaging.

Tumor initiating but differentiated luminal-like breast cancer cells are highly invasive in the absence of basal-like activity.

The majority of human breast cancers exhibit luminal epithelial differentiation. However, most aggressive behavior, including invasion and purported cancer stem cell activity, are considered characteristics of basal-like cells. We asked the following questions: Must luminal-like breast cancer cells become basal-like to initiate tumors or to invade? Could luminally differentiated cells within a basally initiated hierarchy also be tumorigenic? To answer these questions, we used rare and mutually exclusive lineage markers to isolate subsets of luminal-like and basal-like cells from human breast tumors. We enriched for populations with or without prominent basal-like traits from individual tumors or single cell cloning from cell lines and recovered cells with a luminal-like phenotype. Tumor cells with basal-like traits mimicked phenotypic and functional behavior associated with stem cells assessed by gene expression, mammosphere formation and lineage markers. Luminal-like cells without basal-like traits, surprisingly, were fully capable of initiating invasive tumors in NOD SCID gamma (NSG) mice. In fact, these phenotypically pure luminal-like cells generated larger and more invasive tumors than their basal-like counterparts. The tumorigenicity and invasive potential of the luminal-like cancer cells relied strongly on the expression of the gene GCNT1, which encodes a key glycosyltransferase controlling O-glycan branching. These findings demonstrate that basal-like cells, as defined currently, are not a requirement for breast tumor aggressiveness, and that within a single tumor there are multiple "stem-like" cells with tumorigenic potential casting some doubt on the hypothesis of hierarchical or differentiative loss of tumorigenicity.

Tissue proteomics of the human mammary gland: towards an abridged definition of the molecular phenotypes underlying epithelial normalcy.

Our limited understanding of the biological impact of the whole spectrum of early breast lesions together with a lack of accurate molecular-based risk criteria for the diagnosis and assignment of prognostic significance to biopsy findings presents an important problem in the clinical management of patients harboring precancerous breast lesions. As a result, there is a need to identify biomarkers that can better determine the outcome of early breast lesions by identifying subpopulations of cells in breast premalignant disease that are at high-risk of progression to invasive disease. A first step towards achieving this goal will be to define the molecular phenotypes of the various cell types and precursors - generated by the stem cell hierarchy - that are present in normal and benign conditions of the breast. To date there have been very few systematic proteomic studies aimed at characterizing the phenotypes of the different cell subpopulations present in normal human mammary tissue, partly due to the formidable heterogeneity of mammary tissue, but also due to limitations of the current proteomic technologies. Work in our laboratories has attempted to address in a systematic fashion some of these limitations and here we present our efforts to search for biomarkers using normal fresh tissue from non-neoplastic breast samples. From the data generated by the 2D gel-based proteomic profiling we were able to compile a protein database of normal human breast epithelial tissue that was used to support the biomarker discovery program. We review and present new data on the putative cell-progenitor marker cytokeratin 15 (CK15), and describe a novel marker, dihydropyriminidase-related protein 3 (DRP3) that in combination with CK15 and other well known proteins were used to define molecular phenotypes of normal human breast epithelial cells and their progenitors in resting acini, lactating alveoli, and large collecting ducts of the nipple. Preliminary results are also presented concerning DRP3 positive usual ductal hyperplasias (UDHs) and on single cell layer columnar cells (CCCs). At least two bona fide biomarkers of undifferentiated ERα/PgR negative luminal cells emerged from these studies, CK15 and c-KIT, which in combination with transformation markers may lead to the establishment of a protein signature able to identify breast precancerous at risk of progressing to invasive disease.

Proteomic profiling of mammary carcinomas identifies C7orf24, a gamma-glutamyl cyclotransferase, as a potential cancer biomarker.

Breast cancer is the leading cause of cancer deaths in women today and is the most common cancer (excluding skin cancers) among women in the Western world. Although cancers detected by screening mammography are significantly smaller than nonscreening ones, noninvasive biomarkers for detection of breast cancer as early as possible are an urgent need as the risk of recurrence and subsequent death is closely related to the stage of the disease at the time of primary surgery. A set of 123 primary breast tumors and matched normal tissue was analyzed by two-dimensional (2D) gel electrophoresis, and a novel protein, C7orf24, was identified as being upregulated in cancer cells. Protein expression levels of C7orf24 were evaluated by immunohistochemical assays to qualify deregulation of this protein. Analysis of C7orf24 expression showed up-regulation in 36.4 and 23.4% of cases present in the discovery sample set (123 samples) and in an independent large TMA validation data set (2197 samples) of clinically annotated breast cancer specimens, respectively. Survival analysis showed that C7orf24 overexpression defines a subgroup of breast tumors with poor clinical outcome. Up-regulation of C7orf24 was also found in other cancer types. Four of these were investigated in greater detail, and we found that a proportion of tumors (58% in cervical, 38% in lung, 72% in colon, and 46% in breast cancer) expressed C7orf24 at levels exceeding those seen in normal samples. The observed overexpression of this protein in different types of cancer suggests deregulation of C7orf24 to be a general event in epithelial carcinogenesis, indicating that this protein may play an important role in cancer cell biology and thus constitute a novel therapeutic target. Furthermore, as C7orf24 is externalized to the tissue extracellular fluid and can be detected in serum, this protein also represents a potential serological marker.

Epithelial-stromal interaction 1 (EPSTI1) substitutes for peritumoral fibroblasts in the tumor microenvironment.

Tumor cells can activate stroma, yet the implication of this activation in terms of reciprocal induction of gene expression in tumor cells is poorly understood. Epithelial Stromal Interaction 1 (EPSTI1) is an interferon response gene originally isolated from heterotypic recombinant cultures of human breast cancer cells and activated breast myofibroblasts. Here we describe the first immunolocalization of EPSTI1 in normal and cancerous breast tissue, and we provide evidence for a role of this molecule in the regulation of tumor cell properties and epithelial-mesenchymal transition. In general, no EPSTI1 staining was observed in normal breast epithelial cells from reduction mammoplasties (n=25). However, in carcinomas, staining was positive in 22 of 40 biopsies and inversely correlated with the level of differentiation. To address the function of EPSTI1, we expressed EPSTI1 ectopically in one cell line and silenced endogenous EPSTI1 by RNA interference in another. Irrespective of the experimental approach, EPSTI1 expression led to an increase in tumorsphere formation-a property associated with breast stem/progenitor cells. Most remarkably, we show that EPSTI1, by conveying spread of tumor cells, can replace peritumoral activated fibroblasts in a tumor environment assay. These observations implicate EPSTI1 as a hitherto unappreciated regulator of tumor cell properties.

Up-regulated proteins in the fluid bathing the tumour cell microenvironment as potential serological markers for early detection of cancer of the breast.

Breast cancer is by far the most common diagnosed form of cancer and the leading cause of cancer death in women today. Clinically useful biomarkers for early detection of breast cancer could lead to a significant reduction in mortality. Here we describe a detailed analysis using gel-based proteomics in combination with mass spectrometry and immunohistochemistry (IHC) of the tumour interstitial fluids (TIF) and normal interstitial fluids (NIF) collected from 69 prospective breast cancer patients. The goal of this study was to identify abundant cancer up-regulated proteins that are externalised by cells in the tumour microenvironment of most if not all these lesions. To this end, we applied a phased biomarker discovery research strategy to the analysis of these samples rather than comparing all samples among each other, with inherent inter and intra-sample variability problems. To this end, we chose to use samples derived from a single tumour/benign tissue pair (patient 46, triple negative tumour), for which we had well-matched samples in terms of epithelial cell numbers, to generate the initial dataset. In this first phase we found 110 proteins that were up-regulated by a factor of 2 or more in the TIF, some of which were confirmed by IHC. In the second phase, we carried out a systematic computer assisted analysis of the 2D gels of the remaining 68 TIF samples in order to identify TIF 46 up-regulated proteins that were deregulated in 90% or more of all the available TIFs, thus representing common breast cancer markers. This second phase singled out a set of 26 breast cancer markers, most of which were also identified by a complementary analysis using LC-MS/MS. The expression of calreticulin, cellular retinoic acid-binding protein II, chloride intracellular channel protein 1, EF-1-beta, galectin 1, peroxiredoxin-2, platelet-derived endothelial cell growth factor, protein disulfide isomerase and ubiquitin carboxyl-terminal hydrolase 5 were further validated using a tissue microarray containing 70 malignant breast carcinomas of various grades of atypia. A significant number of these proteins have already been detected in the blood/plasma/secretome by others. The next steps, which include biomarker prioritization based on the hierarchal evaluation of these markers, antibody and antigen development, assay development, analytical validation, and preliminary testing in the blood of healthy and breast cancer patients, are discussed.

DNA copy number aberrations in breast cancer by array comparative genomic hybridization.

Array comparative genomic hybridization (CGH) has been popularly used for analyzing DNA copy number variations in diseases like cancer. In this study, we investigated 82 sporadic samples from 49 breast cancer patients using 1-Mb resolution bacterial artificial chromosome CGH arrays. A number of highly frequent genomic aberrations were discovered, which may act as "drivers" of tumor progression. Meanwhile, the genomic profiles of four "normal" breast tissue samples taken at least 2 cm away from the primary tumor sites were also found to have some genomic aberrations that recurred with high frequency in the primary tumors, which may have important implications for clinical therapy. Additionally, we performed class comparison and class prediction for various clinicopathological parameters, and a list of characteristic genomic aberrations associated with different clinicopathological phenotypes was compiled. Our study provides clues for further investigations of the underlying mechanisms of breast carcinogenesis.

Population-based study of peritumoral lymphovascular invasion and outcome among patients with operable breast cancer.

BACKGROUND: Lymphovascular invasion has been associated with poor prognosis in women with breast cancer, but it is unclear whether the presence of lymphovascular invasion should be considered sufficient to reclassify breast cancer patients who are at a low risk of recurrence into a high-risk category. METHODS: Of the 16,172 patients with operable breast cancer who were entered into the Danish Breast Cancer Cooperative Group Registry from January 1, 1996, to December 31, 2002, lymphovascular invasion was classified at primary diagnosis in 16,121 patients as present (n = 2453, 15%) or as absent (n = 13,206, 82%). Patients with at least one of the risk criteria (positive lymph nodes, tumor size > 2 cm, high grade, hormone receptor-negative tumor, or younger than 35 years) were assigned to the high-risk group; the other patients were assigned to the low-risk group. All procedures, including report forms, central review, and querying, were specified in advance. Kaplan-Meier analyses were used to estimate disease-free intervals and overall survival rates among patients with and without lymphovascular invasion, and multivariable analysis was used to adjust for differences in baseline characteristics and therapy. All statistical tests were two-sided. RESULTS: Complete follow-up was achieved for 15,659 patients. The median estimated potential follow-up was 6.4 years for invasive disease-free interval and 7.7 years for overall survival. Invasive disease-free interval and overall survival were statistically significantly associated with lymphovascular invasion within the high-risk group (hazard ratio [HR] for invasive disease = 2.29, 95% confidence interval [CI] = 2.14 to 2.45, P < .001; and HR for death = 2.42, 95% CI = 2.25 to 2.61, P < .001) but not within the low-risk group. At 5 years after surgery, 65.4% (95% CI = 63.5% to 67.3%) and 85.2% (95% CI = 84.5% to 85.9%) of those in the high-risk group with and without lymphovascular invasion were alive; 98.1% (95% CI = 87.6% to 99.7%) and 94.1% (95% CI = 93.2% to 94.8%) of those in the low-risk group with and without lymphovascular invasion were alive. These differences persisted in a multivariable analysis, and for overall survival, a statistically significant interaction (P = .03) was observed between lymphovascular invasion and risk group. CONCLUSIONS: In this prospective population-based study, lymphovascular invasion was not an independent high-risk criterion. Lymphovascular invasion should not by itself be considered sufficient to move patients from a low-risk group to a high-risk group.

Molecular characterization of apocrine carcinoma of the breast: validation of an apocrine protein signature in a well-defined cohort.

Invasive apocrine carcinomas (IACs), as defined by morphological features, correspond to 0.3-4% of all invasive ductal carcinomas (IDC), and despite the fact that they are histologically distinct from other breast lesions there are currently no standard molecular criteria available for their diagnosis and no unequivocal information as to their prognosis. In an effort to address these concerns we have been using protein expression profiling technologies in combination with mass spectrometry and immunohistochemistry (IHC) to discover specific biomarkers that could allow us to molecularly characterize these lesions as well as to dissect some of the steps in the processes underlying breast apocrine metaplasia and development of precancerous apocrine lesions. Establishing these apocrine-specific markers as best practice for the routine pathology evaluation of breast cancer, however, will require their validation in large cohorts of patients. Towards this goal we have composed a panel of antibodies against components of an apocrine protein signature that includes probes against the apocrine-specific markers 15-prostaglandin dehydrogenase (15-PGDH), and acyl-CoA synthetase medium-chain family member 1 (ACSM1), in addition to a set of categorizing markers that are consistently expressed (AR, CD24) or not expressed (ERα, PgR, Bcl-2, and GATA-3) by apocrine metaplasia in benign breast lesions and apocrine sweat glands. This panel was used to analyze a well-defined cohort consisting of 14 apocrine ductal carcinoma in situ (ADCIS), and 33 IACs diagnosed at the Cancer Institute Hospital, Tokyo between 1997 and 2001. Samples were originally classified on the basis of cellular morphology with all cases having more than 90% of the tumour cells exhibiting cytological features typical of apocrine cells. Using the expression of 15-PGDH and/or ACSM1 as the main criterion, but taking into account the expression of other markers, we were able to identify unambiguously 13 out of 14 ADCIS (92.9%) and 20 out of 33 (60.6%) IAC samples, respectively, as being of apocrine origin. Our results demonstrate that IACs correspond to a distinct, even if heterogeneous, molecular subgroup of breast carcinomas that can be readily identified in an unbiased way using a combination of markers that recapitulate the phenotype of apocrine sweat glands (15-PGDH(+), ACSM1(+), AR(+), CD24(+), ERα(-), PgR(-), Bcl-2(-), and GATA-3(-)). These results pave the way for addressing issues such as prognosis of IACs, patient stratification for targeted therapeutics, as well as research strategies for identifying novel therapeutic targets for developing new cancer therapies.

Omics-based profiling of carcinoma of the breast and matched regional lymph node metastasis.

Axillary lymph node (ALN) status is currently used as an important clinical indicator of breast cancer prognosis. However, the molecular mechanisms underlying lymph node metastasis are poorly understood and the relationship between ALN metastasis and the primary tumor remains unclear. In an effort to reveal structural changes in the genome and related protein responses that may drive regional metastatic progression we have analyzed matched pairs of primary breast tumors and ALN metastases both at the genomic and proteomic levels using comparative genomic hybridization (CGH) array, quantitative high-resolution 2-D PAGE in combination with MS, and immunohistochemistry (IHC). Array CGH revealed a remarkable similarity in genomic aberration profiles between the matched primary tumors and the ALN metastases. Quantitative profiling of 135 known proteins also revealed striking similarities in their overall expression patterns, although we observed distinct changes in the levels of individual proteins in some sample pairs. The remarkable similarities of the overall genomic and proteomic profiles between primary tumors and matched ALN metastases are taken to suggest that, in general, key biological characteristics of the primary breast tumor are maintained in the corresponding lymph node metastases. Given that the omics-based technologies are oblivious to changes that only occur in minor cellular subsets we validated the proteomic data using IHC, which provides protein expression information with a valuable topological component. Besides confirming the omics-derived data, the IHC analysis revealed that in two cases the ALN metastases may have been derived from a distinct minor cell subpopulation present in the primary tumor rather than from the bulk of it.

Matrix metalloproteinase 13 is induced in fibroblasts in polyomavirus middle T antigen-driven mammary carcinoma without influencing tumor progression.

Matrix metalloproteinase (MMP) 13 (collagenase 3) is an extracellular matrix remodeling enzyme that is induced in myofibroblasts during the earliest invasive stages of human breast carcinoma, suggesting that it is involved in tumor progression. During progression of mammary carcinomas in the polyoma virus middle T oncogene mouse model (MMTV-PyMT), Mmp13 mRNA was strongly upregulated concurrently with the transition to invasive and metastatic carcinomas. As in human tumors, Mmp13 mRNA was found in myofibroblasts of invasive grade II and III carcinomas, but not in benign grade I and II mammary intraepithelial neoplasias. To determine if MMP13 plays a role in tumor progression, we crossed MMTV-PyMT mice with Mmp13 deficient mice. The absence of MMP13 did not influence tumor growth, vascularization, progression to more advanced tumor stages, or metastasis to the lungs, and the absence of MMP13 was not compensated for by expression of other MMPs or tissue inhibitor of metalloproteinases. However, an increased fraction of thin collagen fibrils was identified in MMTV-PyMT;Mmp13(-/-) compared to MMTV-PyMT;Mmp13(+/+) tumors, showing that collagen metabolism was altered in the absence of MMP13. We conclude that the expression pattern of Mmp13 mRNA in myofibroblasts of invasive carcinomas in the MMTV-PyMT breast cancer model recapitulates the expression pattern observed in human breast cancer. Our results suggest that MMP13 is a marker of carcinoma-associated myofibroblasts of invasive carcinoma, even though it does not make a major contribution to tumor progression in the MMTV-PyMT breast cancer model.

15-prostaglandin dehydrogenase expression alone or in combination with ACSM1 defines a subgroup of the apocrine molecular subtype of breast carcinoma.

Established histopathological criteria divide invasive breast carcinomas into defined groups. Ductal of no specific type and lobular are the two major subtypes accounting for around 75 and 15% of all cases, respectively. The remaining 10% include rarer types such as tubular, cribriform, mucinous, papillary, medullary, metaplastic, and apocrine breast carcinomas. Molecular profiling technologies, on the other hand, subdivide breast tumors into five subtypes, basal-like, luminal A, luminal B, normal breast tissue-like, and ERBB2-positive, that have different prognostic characteristics. An additional subclass termed "molecular apocrine" has recently been described, but these lesions did not exhibit all the histopathological features of classical invasive apocrine carcinomas (IACs). IACs make up 0.5-3% of the invasive ductal carcinomas, and despite the fact that they are morphologically distinct from other breast lesions, there are presently no standard molecular criteria available for their diagnosis and as a result no precise information as to their prognosis. Toward this goal our laboratories have embarked in a systematic proteomics endeavor aimed at identifying biomarkers that may characterize and subtype these lesions as well as targets that may lead to the development of novel targeted therapies and chemoprevention strategies. By comparing the protein expression profiles of apocrine macrocysts and non-malignant breast epithelial tissue we have previously reported the identification of a few proteins that are specifically expressed by benign apocrine lesions as well as by the few IACs that were available to us at the time. Here we reiterate our strategy to reveal apocrine cell markers and present novel data, based on the analysis of a considerably larger number of samples, establishing that IACs correspond to a distinct molecular subtype of breast carcinomas characterized by the expression of 15-prostaglandin dehydrogenase alone or in combination with a novel form of acyl-CoA synthetase medium-chain family member 1 (ACSM1). Moreover we show that 15-prostaglandin dehydrogenase is not expressed by other breast cancer types as determined by gel-based proteomics and immunohistochemistry analysis and that antibodies against this protein can identify IACs in an unbiased manner in a large breast cancer tissue microarray making them potentially useful as a diagnostic aid.

Long-term results of breast conserving surgery vs. mastectomy for early stage invasive breast cancer: 20-year follow-up of the Danish randomized DBCG-82TM protocol.

The main objective of the present study aims at comparing the long-term efficacy of breast conserving surgery (BCS) vs. mastectomy (M) based on a randomized design. The Danish Breast Cancer Cooperative Group (DBCG) conducted the trial (DBCG-82TM) from January 1983 to March 1989 recruiting 1154 patients with invasive breast carcinoma. Follow-up time ended 1(st) May 2006 with a median follow-up time of 19.6 years (time span 17.1-23.3 years). Eligibility criteria included a one-sided, unifocal, primary operable breast carcinoma, patient age below 70 years, probability of satisfactory cosmetic outcome with BCS, and no evidence of disseminated disease. The patients accrued were grouped into three subsets: correctly randomized, suspicion of randomization error, and declining randomization. The main analyses focus on the subgroup of 793 correctly randomized patients representing 70% of the complete series. 10-year recurrence free survival (RFS) and 20-year overall survival (OS) based on intent to treat did not reveal significant differences in outcome between breast conserving surgery vs. mastectomy, p=0.95 and p=0.10, respectively. Including the complete series comprising 1133 eligible patients based on treatment in fact given similarly no significant difference between surgical options could be traced in outcome of 10-year RFS and 20-year OS, p=0.94 and p=0.24, respectively. The pattern of recurrences as a first event in breast conservation vs. mastectomy did not differ significantly irrespective of site, p=0.27. Looking into the type of local relapse, viz., new primaries vs. true recurrences, it appeared that new primaries were significantly associated to BCS, while true recurrences dominated among M treated patients (p<0.001). In conclusion, long-term data indicate that BCS in eligible patients proves as effective as mastectomy both regarding local tumour control, RFS and OS. Local failures as a first event consistent with new primaries are strongly associated with BCS, whereas true recurrence predominates after mastectomy.

Breast cancer in situ. From pre-malignant lesion of uncertain significance to well-defined non-invasive malignant lesion. The Danish Breast Cancer Cooperative Group Register 1977-2007 revisited.

In addition to nationwide standardized pathology forms for operable primary invasive breast cancer, the Danish Breast Cancer cooperative Group (DBCG) in 1982 introduced pathology forms for breast cancer in situ (CIS). The histological reporting form was used primarily for ductal cancer in situ (DCIS) treated with wide local excision. The form however, also provided information on lobular carcinoma in situ (LCIS), atypia and benign lesions. In 1989 the reporting form for DCIS was extended and now provided information on histological subtype, malignancy grade, growth pattern and both Estrogen receptor (ER) and Progesteron receptor (PR) status. Also mastectomy specimens were included. In 2004 the previous malignancy grading was replaced by the Van Nuys classification, and information on microcalcifications was introduced. The axillary status now included the sentinel node technique only. In 2006 the pleomorphic subtype of LCIS was added to histological subtypes. The present work reviews the DBCG guidelines and recommendations concerning CIS adding a brief characterization of the Danish CIS population. It also refers to the introduction of modern molecular pathology and distinction between low-risk and high-risk CIS lesions. A major point is that without the thirty years of outstanding efforts by the DBCG, future research would not be able to meet expectations.

A single lysis solution for the analysis of tissue samples by different proteomic technologies.

Cancer, being a major healthcare concern worldwide, is one of the main targets for the application of emerging proteomic technologies and these tools promise to revolutionize the way cancer will be diagnosed and treated in the near future. Today, as a result of the unprecedented advances that have taken place in molecular biology, cell biology and genomics there is a pressing need to accelerate the translation of basic discoveries into clinical applications. This need, compounded by mounting evidence that cellular model systems are unable to fully recapitulate all biological aspects of human dissease, is driving scientists to increasingly use clinically relevant samples for biomarker and target discovery. Tissues are heterogeneous and as a result optimization of sample preparation is critical for generating accurate, representative, and highly reproducible quantitative data. Although a large number of protocols for preparation of tissue lysates has been published, so far no single recipe is able to provide a "one-size fits all" solubilization procedure that can be used to analyse the same lysate using different proteomics technologies. Here we present evidence showing that cell lysis buffer 1 (CLB1), a lysis solution commercialized by Zeptosens [a division of Bayer (Schweiz) AG], provides excellent sample solubilization and very high 2D PAGE protein resolution both when using carrier ampholytes and immobilized pH gradient strips. Moreover, this buffer can also be used for array-based proteomics (reverse-phase lysate arrays or direct antibody arrays), allowing the direct comparison of qualitative and quantitative data yielded by these technologies when applied to the same samples. The usefulness of the CLB1 solution for gel-based proteomics was further established by 2D PAGE analysis of a number of technically demanding specimens such as breast carcinoma core needle biopsies and problematic tissues such as brain cortex, cerebellum, skeletal muscle, kidney cortex and tongue. This solution when combined with a specific sample preparation technique - cryostat sectioning of frozen specimens - simplifies tissue sample preparation and solves most of the difficulties associated with the integration of data generated by different proteomic technologies.

[Preoperative biopsy diagnosis in suspicion of breast cancer]. / Praeoperativ biopsidiagnostik ved mistanke om brystkraeft.

The golden standard in non-operative breast cancer diagnosis is the triple test, a combination of clinical evaluation, mammography/ultrasound and needle biopsy, either fine needle aspiration cytology (FNAC) or histological core biopsy. FNAC and core biopsy both have advantages and disadvantages but neither of them can act as a decisive diagnostic procedure on its own. The final diagnosis should always be a consensus between the three diagnostic modalities in the triple test. Quality assurance of the pathological diagnosis is a must. The number of uncertain diagnoses i.e. atypia or suspicion of malignancy should be kept at a minimum. These diagnostic categories call for additional diagnostic procedures and thereby cause a delay in reaching the final diagnosis leading to definitive treatment.

[Carcinoma in situ of the breast]. / Carcinoma in situ mammae.

Ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS) represent a proliferation of malignant epithelial cells within the ducts of the breast without invasion through the basement membrane. It is assumed that all invasive carcinomas of the breast are preceded by DCIS or LCIS. However, it is not known what proportion of DCIS or LCIS--if left untreated--will progress to invasive carcinoma. Standard treatment for DCIS is breast-conserving surgery with free margins and radiation therapy. LCIS is usually treated by observation alone.

Invasive lobular breast cancer. Prognostic significance of histological malignancy grading.

Invasive lobular carcinoma (ILC) is the second most reported type of breast cancer in the Danish Breast Cancer Cooperative Group (DBCG). Several histological subtypes exist, with reports of different prognosis. The aim was to present the incidence of ILC in DBCG from 1977-2004, and evaluate tumours regarding diagnosis, histological subtype and grade, and relate to prognosis. Eight hundred and sixty tumours from patients with a diagnosis of ILC or ILC/non-ILC, who underwent breast cancer surgery in the period of 1990-1998, were evaluated. The impact of histological malignancy grade on disease-free survival and overall survival was analysed using a multivariate analysis adjusting for tumour size, hormone receptor status, axillary lymph node status and patient age. The incidence of pure ILC has risen from 5 to 12%, the ILC/non-ILC is constant at 2% of all reported breast cancers in DBCG. Most of the tumours were classical ILC grade II. The majority of the grade III tumours were among the non-classical subtypes, showing a statistically significant worse disease-free and overall survival compared to grade II, regardless of type. The prognosis was the same for grade I and grade II tumours. The number of positive axillary lymph nodes and hormone receptor negative tumours increased among grade III tumours. We conclude that histological malignancy grade has an independent significant impact on the prognosis of ILC, and it should be taken into consideration when planning the postoperative treatment in this group of patients.

Expression of S100A4 by a variety of cell types present in the tumor microenvironment of human breast cancer.

The S100A4 protein, which is involved in the metastasis process, is a member of the S100 superfamily of Ca-binding proteins. Members of this family are multifunctional signaling proteins with dual extra and intracellular functions involved in the regulation of diverse cellular processes. Several studies have established a correlation between S100A4 protein expression and worse prognosis for patients with various malignancies including breast cancer. In this article, we have used specific antibodies in combination with immunohistochemistry (IHC) to identify the cell types that express S100A4 in human breast cancer biopsies obtained from high-risk patients. IHC analysis of 68 tumor biopsies showed that the protein is expressed preferentially by various cell types present in the tumor microenvironment (macrophages, fibroblasts, activated lymphocytes), rather than by the tumor cells themselves. Moreover, we show that the protein is externalized by the stroma cells to the fluid that bathes the tumor microenvironment, where it is found in several forms that most likely correspond to charge variants. Using a specific ELISA test, we detected a significant higher concentration of S100A4 in the tumor interstitial fluid (TIF) as compared to their corresponding normal counterparts (NIF).

Evidence for a stem cell hierarchy in the adult human breast.

Cellular pathways that contribute to adult human mammary gland architecture and lineages have not been previously described. In this study, we identify a candidate stem cell niche in ducts and zones containing progenitor cells in lobules. Putative stem cells residing in ducts were essentially quiescent, whereas the progenitor cells in the lobules were more likely to be actively dividing. Cells from ducts and lobules collected under the microscope were functionally characterized by colony formation on tissue culture plastic, mammosphere formation in suspension culture, and morphogenesis in laminin-rich extracellular matrix gels. Staining for the lineage markers keratins K14 and K19 further revealed multipotent cells in the stem cell zone and three lineage-restricted cell types outside this zone. Multiparameter cell sorting and functional characterization with reference to anatomical sites in situ confirmed this pattern. The proposal that the four cell types are indeed constituents of an as of yet undescribed stem cell hierarchy was assessed in long-term cultures in which senescence was bypassed. These findings identify an adult human breast ductal stem cell activity and its earliest descendants.