Prognostic relevance of cathepsin D detection in micrometastatic cells in the bone marrow of patients with primary breast cancer

Role of cathepsin D induced by Porphyromonas gingivalis lipopolysaccharide in periodontitis

Periodontitis is an inflammatory disease of tooth-supporting tissues caused by oral bacteria. Periodontal ligament loss and alveolar bone destruction occur in progressive periodontitis. Since gingival crevicular fluids (GCF) reflects the inflammatory environment of the periodontal pocket, it is a very important specimen for developing targets for periodontitis diagnosis. An antibody array was performed using GCF collected from healthy participants and patients with periodontitis to identify the proteolytic enzymes involved in periodontitis. Of 21 targets on the antibody array membrane, kallikrein 6 (KLK6), kallikrein 10 (KLK10), cathepsin A (CathA), and cathepsin D (CathD) showed higher levels in periodontitis GCF than in GCF from healthy participants. Lipopolysaccharide stimulation of Porphyromonas gingivalis (PG-LPS) in immortalized gingival fibroblasts only increased CathD protein levels among the four targets. The substrate cleavage activity of CathD was increased in PG-LPS-treated immortalized gingival fibroblast extract. The PG-LPS-induced substrate cleavage effect was abolished by the CathD inhibitor pepstatin A. Osteoclast formation was promoted by treatment with conditioned media from PG-LPS- treated immortalized gingival fibroblasts but inhibited by the CathD inhibitor pepstatin A. These results suggest that PG-LPS affected the osteoclast formation process by increasing CathD expression in cells around the alveolar bone, thereby participating in periodontitis progression.

Functional Relationship and Gene Ontology Classification of Breast Cancer Biomarkers

Breast cancer is a complex disease that still imposes a significant healthcare burden on women worldwide. The etiology of breast cancer is not known but significant advances have been made in the area of early detection and treatment. The advent of advanced molecular biology techniques, mapping of the human genome and availability of high throughput genomic and proteomic strategies opens up new opportunities and will potentially lead to the discovery of novel biomarkers for early detection and prognostication of breast cancer. Currently, many biomarkers, particularly the hormonal and epidermal growth factor receptors, are being utilized for breast cancer prognosis. Unfortunately, none of the biomarkers in use have sufficient diagnostic, prognostic and/or predictive power across all categories and stages of breast cancer. It is recognized that more useful information can be generated if tumors are interrogated with multiple markers. But choosing the right combination of biomarkers is challenging, because 1) multiple pathways are involved, 2) up to 62 genes and their protein products are potentially involved in breast cancer-related mechanisms and 3) the more markers evaluated, the more the time and cost involved. This review summarizes the current literature on selected biomarkers for breast cancer, discusses the functional relationships, and groups the selected genes based on a Gene Ontology™ classification.

The role and clinical relevance of disseminated tumor cells in breast cancer

Tumor cell dissemination is a common phenomenon observed in most cancers of epithelial origin. One-third of breast cancer patients present with disseminated tumor cells (DTCs) in bone marrow at time of diagnosis; these patients, as well as patients with persistent DTCs, have significantly worse clinical outcome than DTC-negative patients. Since DTC phenotype may differ from the primary tumor with regard to ER and HER2 status, reevaluation of predictive markers on DTCs may optimize treatment choices. In the present review, we report on the clinical relevance of DTC detection in breast cancer.

Multidisciplinary breast centres in Germany: a review and update of quality assurance through benchmarking and certification

PURPOSE

This review summarizes the rationale for the creation of breast centres and discusses the studies conducted in Germany to obtain proof of principle for a voluntary, external benchmarking programme and proof of concept for third-party dual certification of breast centres and their mandatory quality management systems to the German Cancer Society (DKG) and German Society of Senology (DGS) Requirements of Breast Centres and ISO 9001 or similar. In addition, we report the most recent data on benchmarking and certification of breast centres in Germany.

METHODS

Review and summary of pertinent publications. Literature searches to identify additional relevant studies. Updates from the DKG/DGS programmes.

RESULTS AND CONCLUSIONS

Improvements in surrogate parameters as represented by structural and process quality indicators suggest that outcome quality is improving. The voluntary benchmarking programme has gained wide acceptance among DKG/DGS-certified breast centres. This is evidenced by early results from one of the largest studies in multidisciplinary cancer services research, initiated by the DKG and DGS to implement certified breast centres. The goal of establishing a nationwide network of certified breast centres in Germany can be considered largely achieved. Nonetheless the network still needs to be improved, and there is potential for optimization along the chain of care from mammography screening, interventional diagnosis and treatment through to follow-up. Specialization, guideline-concordant procedures as well as certification and recertification of breast centres remain essential to achieve further improvements in quality of breast cancer care and to stabilize and enhance the nationwide provision of high-quality breast cancer care.

Micrometastatic disease in breast cancer: clinical implications

The presence of bone marrow disseminated tumour cells (DTCs) was shown to predict poor clinical outcome in early breast cancer. However, peripheral blood is easier to obtain and allows for serial monitoring of minimal residual disease. Towards this aim, circulating tumour cells (CTCs) in the blood are detected using either direct methods, mainly antibody-based assays (immunocytochemistry, immunofluorescence and flow cytometry), or indirect methods, mainly nucleic acid-based assays (detection of mRNA transcripts by reverse transcriptase polymerase chain reaction, RT-PCR). The detection of CTCs using RT-PCR for CK19 was shown to be an independent prognostic factor in women with early breast cancer. Furthermore, considerable progress has been accomplished in genotyping, phenotyping and profiling micrometastatic cells. The challenge now is to integrate minimal residual disease as a prognostic and predictive tool in the management of breast cancer. This requires the standardisation of micrometastatic cell detection and characterisation, which will allow the incorporation of CTCs/DTCs into prospective clinical trials testing their clinical utility.

American Society of Clinical Oncology 2007 update of recommendations for the use of tumor markers in breast cancer

PURPOSE

To update the recommendations for the use of tumor marker tests in the prevention, screening, treatment, and surveillance of breast cancer.

METHODS

For the 2007 update, an Update Committee composed of members from the full Panel was formed to complete the review and analysis of data published since 1999. Computerized literature searches of MEDLINE and the Cochrane Collaboration Library were performed. The Update Committee's literature review focused attention on available systematic reviews and meta-analyses of published tumor marker studies. In general, significant health outcomes (overall survival, disease-free survival, quality of life, lesser toxicity, and cost-effectiveness) were used for making recommendations. Recommendations and

CONCLUSIONS

Thirteen categories of breast tumor markers were considered, six of which were new for the guideline. The following categories showed evidence of clinical utility and were recommended for use in practice: CA 15-3, CA 27.29, carcinoembryonic antigen, estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, urokinase plasminogen activator, plasminogen activator inhibitor 1, and certain multiparameter gene expression assays. Not all applications for these markers were supported, however. The following categories demonstrated insufficient evidence to support routine use in clinical practice: DNA/ploidy by flow cytometry, p53, cathepsin D, cyclin E, proteomics, certain multiparameter assays, detection of bone marrow micrometastases, and circulating tumor cells.

Clinicopathological study of the expression of hsp27, pS2, cathepsin D and metallothionein in primary invasive breast cancer

Expression of the hormone-related proteins hsp27, pS2, and also of cathepsin D (CD) and metallothionein (MT) was studied by immunohistochemistry and analyzed against clinical data in breast cancer. Archived material of paraffin-embedded breast carcinoma tissues from a cohort of 134 patients with primary invasive breast cancer was used. Hsp27 and pS2 (>10% of tumor cells stained) were found to be expressed in 63.6% and 37.6% of cases, respectively, and were correlated negatively with grading (P=0.006 and 0.01) and positively with estrogen receptors (ER) (P=0.04 and 0.04). pS2 expression was correlated with lymph node status (P=0.02), tumor size (P=0.01), progesterone receptor (PR) content (P=0.02), hsp27 (P=0.015) and bcl-2 protein (P=0.001). An inverse relationship between pS2 expression and the expression of p53 protein (P=0.005) and proliferation-associated index MIB1 (P<0.0001) was noted. Stromal cathepsin D was positively correlated with tumor grade (P=0.01), PCNA (P=0.007), MIB1 (P=0.001) and p53 (P=0.01), and negatively with ER (P=0.04) and bcl-2 (P<0.0001). MT was correlated positively with stromal CD (P=0.007) and inversely with PgR (P=0.04). Univariate analysis showed CD expression to be a positive prognostic factor for survival (P=0.035), with borderline significance, while MT was more strongly positive (P=0.01). However, none of the proteins studied was found to be related to disease outcome in univariate analysis. Our data show that hsp27, pS2 and stromal CD expression may reflect tumor differentiation and the functional status of ER in breast cancer, but stromal CD and tumor MT expression were the only factors found that may be of limited prognostic value.

Antigenic profiles of disseminated breast tumour cells and microenvironment in bone marrow

AIMS

Thirty per cent of breast cancer patients with axillary lymph node negative at primary surgery will relapse within 10 years. This may be caused by disseminated tumour cells from the primary tumour. This study report the phenotypic profiles of disseminated tumour cells and microenvironmental characteristics in bone marrow of breast cancer.

METHODS

We detected the biologic markers on the disseminated tumour cells with immunocytochemical staining, analysed the immunological changes through flow-cytometry, and investigated the u- PA activity in the plasma of bone marrow.

RESULTS

With the immunocytochemical staining of EMA and CK19, we detected micrometastasis in thirty out of 72 (41.67%) breast cancer patients. Compared with the primary tumours, disseminated tumour cells expressed low protein cyclin D1, P53, Ki-67, EGFR, and high protein P21. The percentage of memory CD4+ T cells was significantly higher in the micrometastasis-positive group than in the micrometastasis-negative group. Tumour size and axillary lymph node status were found to be significantly correlated with the u- PA activity level.

CONCLUSIONS

Immunophenotypic profiles of disseminated tumour cells could be measured by immunocytochemical staining and microenvironment can be analysed by flow cytometry.

Bone marrow micrometastasis in breast cancer

BACKGROUND

Several studies have demonstrated that bone marrow micrometastasis in patients with breast cancer is an independent prognostic factor for systemic recurrence and poorer survival.

METHODS

This review describes the detection and clinical significance of micrometastatic cells in bone marrow, and examines the correlation between such micrometastasis and established clinicopathological prognostic factors. The relevant English language literature on bone marrow micrometastasis in breast cancer was searched via Medline (1975-2002), cross-referencing with key articles on the subject.

RESULTS AND CONCLUSION

The balance of evidence favours the hypothesis that bone marrow micrometastasis impacts on disease-free and overall survival. Further prospective studies are required to examine this in greater detail, with particular reference to early node-negative breast cancer and the value of adjuvant systemic therapy in patients with bone marrow micrometastasis.

Simultaneous immunohistochemical detection of tumor cells in lymph nodes and bone marrow aspirates in breast cancer and its correlation with other prognostic factors

PURPOSE

We studied the prognostic and predictive value of immunohistochemically detected occult tumor cells (OTCs) in lymph nodes and bone marrow aspirates obtained from node-negative breast cancer patients. All were classified as distant metastases-free using conventional staging methods.

PATIENTS AND METHODS

A total of 484 patients with pT1-2N0M0 breast cancer and 70 with pT1-2N1M0 breast cancer and a single affected lymph node participated in our trial. Ipsilateral axillary lymph nodes and intraoperatively aspirated bone marrow were examined. All samples were examined for OTCs using monoclonal antibodies to cytokeratins 8, 18, 19. Immunohistological findings were correlated with other prognostic factors. The mean follow-up was 54 +/- 24 months.

RESULTS

OTCs were detected in 180 (37.2%) of 484 pT1-2N0M0 patients: in the bone marrow of 126 patients (26.0%), in the lymph nodes of 31 patients (6.4%), and in bone marrow and lymph nodes of 23 (4.8%) patients. Of the 70 patients with pT1-2N1MO breast cancer and a single involved lymph node, OTCs were identified in the bone marrow of 26 (37.1%). The ability to detect tumor cells increased with the following tumor features: larger size, poor differentiation, and higher proliferation. Tumors of patients with OTCs more frequently demonstrated lymph node invasion, blood vessel invasion, higher urokinase-type plasminogen activator levels, and increased PAI-1 concentrations. Patients with detected OTCs showed reduced disease-free survival (DFS) and overall survival (OAS) rates that were comparable to those observed in patients who had one positive lymph node. Multivariate analysis of prognostic factors revealed that OTCs, histological grading, and tumor size are significant predictors of DFS; OTCs and grading of OAS.

CONCLUSION

OTCs detected by simultaneous immunohistochemical analysis of axillary lymph nodes and bone marrow demonstrate independent metastatic pathways. Although OTCs were significantly more frequent in patients with other unfavorable prognostic factors, they were confirmed as an independent prognostic factor for pT1-2N0M0, R0 breast cancer patients.

Bone marrow and lymph node assessment for minimal residual disease in patients with breast cancer

The immunocytological detection of disseminated epithelial cells in bone marrow in patients with breast cancer has been performed at many hospitals and institutes since the early 1980s. Despite numerous publications in this field, it has not been possible to standardize the method and establish the 'ideal' antibody, either nationally or internationally. Molecular biological methods using PCR technology could extend the diagnostic spectrum. However, one of the major problems in breast cancer is the lack of a disease-specific marker gene. As a result, immunocytology is still the standard procedure for tumour cell detection. The detection of disseminated single cells in bone marrow in primary breast cancer (also known as minimal residual disease) is a new prognostic factor for disease-free and overall survival. This has been demonstrated in two large (N > 300) groups and several small to medium groups (N = 50-300). As a marker of dissemination in a target organ for metastasis this prognostic factor corresponds much more closely to the tendency of breast cancer to early haematogenic spread. Tumour cell detection may predict the course of the disease better than the axillary lymph node status. Bone marrow aspiration and detection of disseminated cells might replace lymph node dissection, at least in those patients with small tumours and no clinical signs of lymph node involvement. This strategy will soon be investigated in appropriate studies. Another possible clinical use might be in deciding on whether or not to give adjuvant systemic therapy to node-negative patients. Patients with positive tumour cell detection are at a higher risk of subsequent metastasis, even if the axillary nodes are histologically normal. The immunohistological or molecular biological detection of tumour cells in axillary lymph nodes might also be very useful, now that it has been shown that a considerable subset of patients determined to be node-negative by means of conventional methods, are positive according to these new techniques. These methods could be a useful supplement to sentinel node biopsy. A further potential use of this method is in monitoring therapy with new treatment modalities such as gene therapy and immunotherapy. Repeated bone marrow aspiration can provide information on the success of therapy in minimal residual disease (cytoreduction). Immunocytochemical investigation of individual cells may be useful in studying the pathogenesis of metastasis, in particular in the skeleton. Phenotyping of cells might allow statements to be made on the metastatic potential of cells and the question of cell dormancy. It remains to be hoped that this aspect of minimal residual disease will be granted more attention in future.

Capillary electrophoretic determination of cathepsin D activity using Oregon Green-labeled hemoglobin

Cathepsin D is an aspartyl protease of lysosomal origin and functions in a variety of roles including protein turnover, catabolism of peptide hormones, antigen processing and presentation, and neoplastic disease. In breast cancer, the level of cathepsin D has been linked to metastasis and prognosis for survivability. Many of these studies concerning the role of cathepsin D in cancer have used immunological detection methods to determine the level of enzyme. These indirect methods to assess the cathepsin D level may not reflect enzyme activity accurately. The significance of cathepsin D to physiological and pathophysiological processes suggests that rapid and sensitive methods for determining cathepsin D activity would contribute to a more complete assessment of this enzyme in its various roles. This work describes a procedure to determine cathepsin D activity based on hydrolysis of fluorescently labeled hemoglobin and employs capillary electrophoresis to separate and measure the products of reaction. A single major cleavage product, representing the first 32 residues of the hemoglobin alpha-chain, appeared after a very short incubation time (less than 10 min) and was used to determine activity. The procedure described here requires very small sample volumes, has a low detection limit (approximately 10(-9) M) and thus represents an additional approach to determine cathepsin D activity in biological samples.