Ten-year analysis of the prospective multicentre Chemo-N0 trial validates American Society of Clinical Oncology (ASCO)-recommended biomarkers uPA and PAI-1 for therapy decision making in node-negative breast cancer patients

Paracrine effects of stem cells in wound healing and cancer progression (Review)

Stem cells play an important role in tissue repair and cancer development. The capacity to self-renew and to differentiate to specialized cells allows tissue-specific stem cells to rebuild damaged tissue and cancer stem cells to initiate and promote cancer. Mesenchymal stem cells, attracted to wounds and cancer, facilitate wound healing and support cancer progression primarily by secreting bioactive factors. There is now growing evidence that, like mesenchymal stem cells, also tissue-specific and cancer stem cells manipulate their environment by paracrine actions. Soluble factors and microvesicles released by these stem cells have been shown to protect recipient cells from apoptosis and to stimulate neovascularization. These paracrine mechanisms may allow stem cells to orchestrate wound healing and cancer progression. Hence, understanding these stem cell-driven paracrine effects may help to improve tissue regeneration and cancer treatment.

Involvement of urokinase-type plasminogen activator system in cancer: an overview

Currently, there are several studies supporting the role of urokinase-type plasminogen activator (uPA) system in cancer. The association of uPA to its receptor triggers the conversion of plasminogen into plasmin. This process is regulated by the uPA inhibitors (PAI-1 and PAI-2). Plasmin promotes degradation of basement membrane and extracellular matrix (ECM) components as well as activation of ECM latent matrix metalloproteases. Degradation and remodeling of the surrounding tissues is crucial in the early steps of tumor progression by facilitating expansion of the tumor mass, release of tumor growth factors, activation of cytokines as well as induction of tumor cell proliferation, migration, and invasion. Hence, many tumors showed a correlation between uPA system component levels and tumor aggressiveness and survival. Therefore, this review summarizes the structure of the uPA system, its contribution to cancer progression, and the clinical relevance of uPA family members in cancer diagnosis. In addition, the review evaluates the significance of uPA system in the development of cancer-targeted therapies.

An ultra-sensitive immunoassay for quantifying biomarkers in breast tumor tissue

Urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor type-1 (PAI-1) have been validated at the highest level of evidence as clinical biomarkers of prognosis in breast cancer. The American Society of Clinical Oncology recommends using uPA and PAI-1 levels in breast tumors for deciding whether patients with newly diagnosed node-negative breast cancer can forgo adjuvant chemotherapy. The sole validated method for quantifying uPA and PAI-1 levels in breast tumor tissue is a colorimetric ELISA assay that takes 3 days to complete and requires 100-300 mg of fresh or frozen tissue. In this study we describe a new assay method for quantifying PAI-1 levels in human breast tumor tissue. This assay combines pressure-cycling technology to extract PAI-1 from breast tumor tissue with a highly sensitive liposome polymerase chain reaction immunoassay for quantification of PAI-1 in the tissue extract. The new PAI-1 assay method reduced the total assay time to one day and improved assay sensitivity and dynamic range by >100, compared to ELISA.

Breast Cancer Biomarkers: Utility in Clinical Practice

Breast cancer is a heterogeneous disease. For the past decades, new technical tools have been developed for biomarkers at the DNA, RNA and protein levels to better understand the biology of breast cancer. This progress is essential to classify the disease into clinically relevant subtypes, which may lead to new therapeutic opportunities. Novel biomarker development is paramount to deliver personalized cancer therapies. Further, tumor evolution, being natural or under treatment pressure, should be monitored and "liquid biopsies" by detecting circulating tumor cells or circulating free tumor DNA in blood samples will become an important option. This paper reviews the new generation of biomarkers and the current evidence to demonstrate their analytical validity, clinical validity and clinical utility.

American Society of Clinical Oncology highlights 2013: breast cancer and gynecological malignancies

The American Society of Clinical Oncology 2013 Annual Meeting took place from May 31 until June 4 2013 in Chicago (IL, USA). Highlights within the area of gynecological oncology and breast cancer included two studies in cervical cancer addressing screening as well as treatment of advanced disease. In breast cancer, the presented studies covered a wide range of topics from local therapy to targeted therapy in the advanced setting. They were not practice changing but rather for the most part confirmatory of earlier findings. Last but not least, a positive Phase III study, BOLERO III, proved the hypothesis that trastuzumab resistance can be overcome by intracellular signal transduction using the mTOR inhibitor everolimus.

Molecular and protein markers for clinical decision making in breast cancer: today and tomorrow

In early breast cancer (eBC), established clinicopathological factors are not sufficient for clinical decision making particularly regarding adjuvant chemotherapy since substantial over- or undertreatment may occur. Thus, novel protein- and molecular markers have been put forward as decision aids. Since these potential prognosis and/or predictive tests differ substantially regarding their methodology, analytical and clinical validation, this review attempts to summarize the essential facts for clinicians. This review focuses on those markers which are the most advanced so far in their development towards routine clinical application, i.e. two protein markers (i.e. uPA/PAI-1 and IHC4) and six molecular multigene tests (i.e. Mammaprint®, Oncotype DX®, PAM50, Endopredict®, the 97-gene genomic grade, and 76 gene Rotterdam signatures). Next to methodological aspects, we summarized the clinical evidences, in particular the main prospective clinical trials which have already been fully recruited (i.e. MINDACT, TAILORx, WSG PLAN B) or are still ongoing (i.e. RxPONDER/SWOG S1007, WSG-ADAPT). Last but not least, this review points out the key elements for clinicians to select one test among the wide panel of proposed assays, for a specific population of patients in term of level of evidence, analytical and clinical validity as well as cost effectiveness.

Cathepsin D stimulates the activities of secreted plasminogen activators in the breast cancer acidic environment

Two proteases cathepsin D (cath D) and urokinase plasminogen activator (uPA) are tissue markers associated with an increased risk of metastasis in breast cancer. We investigated whether cath D, the major aspartyl protease overexpressed by breast cancer cells can trigger a proteolytic cascade via activation of plasminogens at the extracellular pH measured in hypoxic tumors. The effects of the aspartyl protease inhibitor pepstatin on the plasminogen activator (PA) system were analysed by conditioning media of human MDA-MB231 breast cancer cells at pH 6.6 and pH 7.4. Zymography analysis of culture media showed that pepstatin inhibited the secreted activity of tissue-type plasminogen activator (tPA) but not that of uPA. tPA was identified on the basis of the molecular weight, the immunoreactivity with relevant antibodies and the resistance to amiloride, a specific uPA inhibitor. The secreted tPA activity measured by a chromogenic assay in the presence of amiloride was also inhibited by pepstatin at pH 6.6. Surprisingly, pepstatin did not affect secreted tPA protein concentration but markedly increased the amount of the secreted plasminogen activator inhibitor-1 (PAI-1). We conclude that cath D overexpressed by these cells, stimulates at pH 6.6, but not at neutral pH, the extracellular PA proteolytic activity indirectly via PAI-1 proteolysis. This suggests that cath D at acidic pH close to the hypoxic regions of solid tumors, contributes to trigger a proteolytic cascade facilitating cancer cell invasion and metastasis.

WSG ADAPT - adjuvant dynamic marker-adjusted personalized therapy trial optimizing risk assessment and therapy response prediction in early breast cancer: study protocol for a prospective, multi-center, controlled, non-blinded, randomized, investigator initiated phase II/III trial

BACKGROUND

Adjuvant treatment decision-making based on conventional clinical/pathological and prognostic single molecular markers or genomic signatures is a therapeutic area in which over-/under-treatment are still key clinical problems even though substantial and continuous improvement of outcome has been achieved over the past decades. Response to therapy is currently not considered in the decision-making procedure.ADAPT is one of the first new generation (neo)adjuvant trials dealing with individualization of (neo)adjuvant decision-making in early breast cancer and aims to establish early predictive surrogate markers, e.g., Ki-67, for therapy response under a short induction treatment in order to maximally individualize therapy and avoid unnecessary toxicity by ineffective treatment.

METHODS/DESIGN

The prospective, multi-center, controlled, non-blinded, randomized, investigator initiated phase II/III ADAPT trial has an innovative "umbrella" protocol design. The "umbrella" is common for all patients, consisting of dynamic testing of early therapy response. ADAPT will recruit 4,936 patients according to their respective breast cancer subtype in four distinct sub-trials at 80 trial sites in Germany; 4,000 patients with hormone receptor positive (HR+) and HER2 negative disease will be included in the ADAPT HR+/HER2- sub-trial, where treatment decision is based on risk assessment and therapy response to induction therapy, and 380 patients will be included in ADAPT HER2+/HR+. A further 220 patients will be included in ADAPT HER2+/HR- and 336 patients will be recruited for ADAPT Triple Negative. These three sub-trials focus on identification of early surrogate markers for therapy success in the neoadjuvant setting. Patients will be allocated to the respective sub-trial according to the result of their diagnostic core biopsy, as reported by local/central pathology for HR and HER2 status.

DISCUSSION

Recent trials, such as the GeparTrio, have shown that response-guided therapy using clinical response may improve outcome. For chemotherapy or HER2-targeted treatment, pathologic complete response in a neoadjuvant setting is an excellent predictor of outcome. For endocrine therapy, response to short induction treatment - as defined by decrease in tumor cell proliferation - strongly correlates with outcome. ADAPT now aims to combine static prognostic and dynamic predictive markers, focusing not just on single therapeutic targets, but also on general markers of proliferation and cell death. Biomarker analysis will help to optimize selection of subtype-specific treatment.

TRIAL REGISTRATION

ClinicalTrials.gov: ADAPT Umbrella: NCT01781338; ADAPT HR+/HER2-: NCT01779206; ADAPT HER2+/HR+: NCT01745965; ADAPT HER2+/HR-: NCT01817452; ADAPT TN:NCT01815242.

Prognostic and Predictive Markers for Treatment Decisions in Early Breast Cancer

Breast cancer clinically represents a heterogeneous disease. Over the last decades, the integration of prognostic and predictive markers in treatment decisions has led to a more individualized and optimized therapy. While prognosis describes the risk of disease recurrence and disease-related death after diagnosis without the influence of therapy, prediction illustrates the probability of efficacy or response of a specific therapeutic measure. The substantial decline in breast cancer mortality seen over the last 20 years is primarily due to the delivery of adjuvant systemic therapy. It is important that clinical decisions are made to minimize overtreatment, under-treatment, and incorrect treatment. Improved understanding of breast cancer biology together with the utilization of classical biomarkers and the identification of new markers or profiles is increasingly defining who should receive cancer therapy and what therapy offers the best efficacy. The molecular targets as the prerequisite for successful concepts of specific therapies like anti-estrogens, antibodies, or small molecules, have therefore high clinical value in regards to prognosis as well as prediction.

Prospective evaluation of prognostic factors uPA/PAI-1 in node-negative breast cancer: phase III NNBC3-Europe trial (AGO, GBG, EORTC-PBG) comparing 6×FEC versus 3×FEC/3×Docetaxel

BACKGROUND

Today, more than 70% of patients with primary node-negative breast cancer are cured by local therapy alone. Many patients receive overtreatment by adjuvant chemotherapy due to inadequate risk assessment. So far, few clinical trials have prospectively evaluated tumor biology based prognostic factors. Risk assessment by a biological algorithm including invasion factors urokinase-type plasminogen activator (uPA) and its inhibitor plasminogen activator inhibitor type 1 (PAI-1) will assess up to 35-55% of node-negative patients as low-risk and thus avoid chemotherapy. In contrast, a clinical-pathological algorithm will only classify 20-40% of patients as low-risk. High-risk node-negative patients should receive chemotherapy. Anthracycline-based regimens are accepted as a standard, the additional benefit of taxanes remains an open question.

METHODS/DESIGN

The international NNBC3 ("Node Negative Breast Cancer 3-Europe") trial compares biological risk assessment (UP) using invasion factors uPA/PAI-1 with a clinical-pathological algorithm (CP). In this trial, the type of risk assessment (CP or UP) was chosen upfront by each center for its patients. Fresh frozen tissue was obtained to determine uPA/PAI-1 using an enzyme-linked immunosorbent assay (ELISA). Patients assessed as high-risk were stratified by human epidermal growth factor receptor 2 (HER2) status and then randomised to receive anthracycline-containing chemotherapy 5-Fluorouracil (F)/Epirubicin (E)/Cyclophosphymide (C) or an anthracycline-taxane sequence (FE(100)C*6 versus FE(100)C*3 followed by Docetaxel(100)*3).

DISCUSSION

In this trial, 4,149 node-negative patients with operable breast cancer from 153 centers in Germany and France were included since 2002. Measurement of uPA/PAI-1 by ELISA was performed with standardised central quality assurance for 2,497 patients (60%) from 56 "UP"-centers. The NNBC 3-Europe trial showed that inclusion of patients into a clinical phase III trial is feasible based on biological testing of fresh frozen tumor material. In addition, 2,661 patients were classified as high-risk and thus received chemotherapy. As adjuvant chemotherapy, 1,334 high-risk patients received FE(100)C-Docetaxel(100), and 1,327 received French FE(100)C. No unexpected toxicities were observed. Chemotherapy efficacy and comparison of UP with CP will be evaluated after longer follow-up.

TRIAL REGISTRATION

clinical Trials.gov NCT01222052.