Michael Gnant

Medical University of Vienna, Wien, Vienna, Austria

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Publications (291)

  • [Show abstract] [Hide abstract] ABSTRACT: The response to neoadjuvant chemotherapy in breast cancer patients is usually assessed by pCR and RCB score. However, the prognostic value of these parameters is still in discussion. We showed recently that an epirubicin/docetaxel therapy is associated with an increase in the cell death marker high-mobility group box 1 protein (HMGB1) in the circulation. Here, we investigate whether this increase correlates with the long-term outcome. Thirty-six early breast cancer patients under neoadjuvant epirubicin/docetaxel combination chemotherapy were included in this study. To determine the immediate effect of this treatment on HMGB1, we collected blood samples before and 24–96 h after the initial dose. This time course was then compared to the 5-year follow-up of the patients. HMGB1 levels varied before chemotherapy between 4.1 and 11.3 ng/mL and reacted differently in response to therapy. Some patients showed an increase while others did not show any changes. Therefore, we subdivided the patient collective into two groups: patients with an at least 1.1 ng/mL increase in HMGB1 and patients with smaller changes. The disease-free survival was longer in the HMGB1 increase group (56.2 months vs. 46.6 months), but this difference did not reach significance. The overall survival (OS) was significantly better in patients with an increase in HMGB1 (log rank P = 0.021). These data suggest that an immediate increase in HMGB1 levels correlates with improved outcome in early breast cancer patients receiving neoadjuvant chemotherapy, and may be a valuable complementary biomarker for early estimation of prognosis.
    Article · Jul 2016 · Cancer Medicine
  • [Show abstract] [Hide abstract] ABSTRACT: Despite recent improvements, triple-negative breast cancer (TNBC) remains a breast cancer subtype with poor prognosis. TP53 mutations are commonly associated with TNBC, suggesting a role in breast cancer carcinogenesis. In addition to mutations, several reports focused on TP53 polymorphisms and their association with breast cancer risk and outcome. TP53 codon Pro72Arg polymorphism may predict response to anti-cancer therapy as Pro72 is apparently less effective in the induction of apoptosis. Here, we investigated a potential association of TP53 mutations with TP53 codon 72 polymorphism and clinical outcome in a homogeneous cohort of TNBC patients. DNA isolated from formalin-fixed paraffin-embedded tissue of 35 consecutive TNBC patients was investigated for TP53 mutation and TP53 codon 72 polymorphic status by Sanger sequencing. The kind of TP53 mutations were associated with particular polymorphic Pro72Arg genotypes. Frameshift mutations were significantly correlated with Pro/Pro carriers, nonsense mutations showed a trend for Pro/Arg carriers. Despite this observation no association with clinical outcome was observed. Further studies with larger and more homogeneous cohorts are warranted in order to elucidate a potential association of TP53 Pro72Arg polymorphism and particular TP53 mutations with TNBC carcinogenesis and outcome.
    Article · May 2016 · memo - Magazine of European Medical Oncology
  • Michael Gnant
    Article · May 2016 · European journal of cancer (Oxford, England: 1990)
  • Michael Gnant · Guenther G Steger · Rupert Bartsch
    Article · May 2016 · The Lancet Oncology
  • [Show abstract] [Hide abstract] ABSTRACT: Background: Totally implanted access ports (PACs) are valuable tools for the treatment of patients with cancer because they ease the administration of chemotherapy, stem cells, and supportive care by reducing the rate of peripheral vein punctures. Objectives: The purpose of this study was to evaluate the satisfaction and impairments of activities of daily living of ambulatory patients with PAC systems receiving chemotherapy. Methods: This cross-sectional, questionnaire-based study evaluated 202 patients with PAC systems in a comprehensive cancer center and cancer rehabilitation center. From November 2012 to August 2013, patients were invited to answer a questionnaire concerning quality of life and satisfaction with their PAC devices. Data regarding PAC-related complications were collected retrospectively by searching patients' medical history. Findings: A total of 202 patients with 230 PAC devices were included. Median time from PAC implantation to inclusion in the study was nine months. Surgical complications occurred in some cases, with bleeding and hematoma being the most frequently observed events. Late complications consisted of infections, drug extravasation, PAC malposition, PAC malfunction, and thrombosis. A third of the patients reported that their PAC interfered with activities of daily living. However, most agreed that PAC systems alleviated the burden of chemotherapy administration, and the vast majority said they would choose the implantation of a PAC system for chemotherapy administration again.
    Article · Apr 2016 · Clinical journal of oncology nursing
  • [Show abstract] [Hide abstract] ABSTRACT: Background: Neratinib, an irreversible tyrosine-kinase inhibitor of HER1, HER2, and HER4, has clinical activity in patients with HER2-positive metastatic breast cancer. We aimed to investigate the efficacy and safety of 12 months of neratinib after trastuzumab-based adjuvant therapy in patients with early-stage HER2-positive breast cancer. Methods: We did this multicentre, randomised, double-blind, placebo-controlled, phase 3 trial at 495 centres in Europe, Asia, Australia, New Zealand, and North and South America. Eligible women (aged ≥18 years, or ≥20 years in Japan) had stage 1-3 HER2-positive breast cancer and had completed neoadjuvant and adjuvant trastuzumab therapy up to 2 years before randomisation. Inclusion criteria were amended on Feb 25, 2010, to include patients with stage 2-3 HER2-positive breast cancer who had completed trastuzumab therapy up to 1 year previously. Patients were randomly assigned (1:1) to receive oral neratinib 240 mg per day or matching placebo. The randomisation sequence was generated with permuted blocks stratified by hormone receptor status (hormone receptor-positive [oestrogen or progesterone receptor-positive or both] vs hormone receptor-negative [oestrogen and progesterone receptor-negative]), nodal status (0, 1-3, or ≥4), and trastuzumab adjuvant regimen (sequentially vs concurrently with chemotherapy), then implemented centrally via an interactive voice and web-response system. Patients, investigators, and trial sponsors were masked to treatment allocation. The primary outcome was invasive disease-free survival, as defined in the original protocol, at 2 years after randomisation. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00878709. Findings: Between July 9, 2009, and Oct 24, 2011, we randomly assigned 2840 women to receive neratinib (n=1420) or placebo (n=1420). Median follow-up time was 24 months (IQR 20-25) in the neratinib group and 24 months (22-25) in the placebo group. At 2 year follow-up, 70 invasive disease-free survival events had occurred in patients in the neratinib group versus 109 events in those in the placebo group (stratified hazard ratio 0·67, 95% CI 0·50-0·91; p=0·0091). The 2-year invasive disease-free survival rate was 93·9% (95% CI 92·4-95·2) in the neratinib group and 91·6% (90·0-93·0) in the placebo group. The most common grade 3-4 adverse events in patients in the neratinib group were diarrhoea (grade 3, n=561 [40%] and grade 4, n=1 [<1%] vs grade 3, n=23 [2%] in the placebo group), vomiting (grade 3, n=47 [3%] vs n=5 [<1%]), and nausea (grade 3, n=26 [2%] vs n=2 [<1%]). QT prolongation occurred in 49 (3%) patients given neratinib and 93 (7%) patients given placebo, and decreases in left ventricular ejection fraction (≥grade 2) in 19 (1%) and 15 (1%) patients, respectively. We recorded serious adverse events in 103 (7%) patients in the neratinib group and 85 (6%) patients in the placebo group. Seven (<1%) deaths (four patients in the neratinib group and three patients in the placebo group) unrelated to disease progression occurred after study drug discontinuation. The causes of death in the neratinib group were unknown (n=2), a second primary brain tumour (n=1), and acute myeloid leukaemia (n=1), and in the placebo group were a brain haemorrhage (n=1), myocardial infarction (n=1), and gastric cancer (n=1). None of the deaths were attributed to study treatment in either group. Interpretation: Neratinib for 12 months significantly improved 2-year invasive disease-free survival when given after chemotherapy and trastuzumab-based adjuvant therapy to women with HER2-positive breast cancer. Longer follow-up is needed to ensure that the improvement in breast cancer outcome is maintained. Funding: Wyeth, Pfizer, Puma Biotechnology.
    Article · Feb 2016 · The Lancet Oncology
  • Anna Bachmayr-Heyda · Stefanie Aust · Katharina Auer · [...] · Dietmar Pils
    Article · Jan 2016 · Clinical Cancer Research
  • Michael Gnant
    [Show abstract] [Hide abstract] ABSTRACT: Breast cancer is the most common malignancy among women worldwide and is a leading cause of death; it metastasizes frequently to bone. Anti-resorptive drugs such as bisphosphonates (of which the aminobisphosphonate zoledronic acid is the most potent one) or the anti-Rank-ligand antibody denosumab, are used both for the treatment of bone metastases and for treating and or preventing osteoporosis. Recently, these drugs have also been investigated in large clinical trials as to whether their adjuvant use can improve outcomes of early breast cancer patients, based on the prevention of metastases. Trials results of large adjuvant zoledronic acid trials have been presented but are, however, conflicting. Whereas ABCSG-12 and ZO-FAST demonstrate clear-cut outcome benefits based on the prevention of metastases in bone and outside bone, AZURE overall did not show a significant difference. In the post-menopausal subgroup, however, AZURE also demonstrated significant disease-free and overall survival benefits for patients treated with zoledronic acid. Similar observations in other bisphosphonate trials have led to the hypothesis that the endocrine environment may play an important role in determining the anti-cancer effects of anti-resorptive drugs. A recent EBCTCG individual patient-level meta-analysis has confirmed a significant benefit of adjuvant bisphosphonates in a low-estrogen environment, either in post-menopausal patients or pre-menopausal patients treated with ovarian function suppression. Ongoing large trials will show whether any of this is also true for the adjuvant use of denosumab.
    Chapter · Dec 2015
  • Guenther G Steger · Michael Gnant · Rupert Bartsch
    [Show abstract] [Hide abstract] ABSTRACT: Introduction Breast cancer is a heterogeneous disease comprising different biological subtypes. In two thirds of tumours, expression of steroid-receptors is present, allowing for targeted treatment with endocrine therapy. In metastatic breast cancer, sequential administration of different non-cross resistant drugs offers a chance to delay cytotoxic chemotherapy. Activity of endocrine therapy, however, decreases with time as indicated by a shorter progression-free survival interval with every further treatment line, suggesting onset of resistance. Current research therefore focuses on prevention or delay of resistance by combining endocrine therapy with other targeted treatment approaches such as small-molecule pathway-inhibitors. Indeed, combining the steroidal aromatase-inhibitor exemestane with the mTor-inhibitor everolimus doubles activity of endocrine therapy in a pretreated population albeit at the price of increased toxicity. Data from several clinical trials suggest that inhibitors of the cycline-dependent kinases (CDK) 4 and 6 are able to delay or reverse resistance to endocrine therapy as well, while tolerability may be superior. Areas Covered This review provides a summary of clinical data on CDK 4/6 inhibitors, summarizes the biological rational for their use and provides an outlook to future developments in this field. A systematic literature search was performed in order to identify publications concerning the use of CDK 4/6 inhibitors in breast cancer. The search included original research articles, abstracts from major conferences and reviews published from 2005 to 2015 and was limited to English-language publications. Expert opinion Based upon available data regarding activity and tolerability, it is believed that CDK 4/6 inhibitors will evolve to become a valuable addition to the therapeutic options in metastatic breast cancer.
    Article · Dec 2015 · Expert Opinion on Pharmacotherapy
  • Nadia Harbeck · Michael Gnant · Christoph Thomssen
    Article · Dec 2015 · Breast Care
  • Michael Gnant
    Article · Nov 2015 · The Lancet
  • Hans-Jörg Senn · Beat Thürlimann · Michael Gnant
    Article · Oct 2015 · Breast (Edinburgh, Scotland)
  • Dataset · Oct 2015
  • Stephanie Strobl · Belgin Korkmaz · Yelena Devyatko · [...] · Michael Gnant
    [Show abstract] [Hide abstract] ABSTRACT: Randomized trials have studied bisphosphonates in the adjuvant setting of early breast cancer to investigate their ability to prevent treatment-induced bone loss. Trial results have also suggested their potential to prevent disease recurrence and metastases. These trials are summarized in this review. A recent patient-level meta-analysis by the Early Breast Cancer Trials Collaborative Group (EBCTCG) finds convincing evidence that adjuvant antiresorptive treatments provide persistent benefits to breast cancer patients in low-estrogen situations and should be considered an important part of the treatment algorithm. Expected final online publication date for the Annual Review of Medicine Volume 67 is January 14, 2016. Please see http://www.annualreviews.org/catalog/pubdates.aspx for revised estimates.
    Article · Aug 2015 · Annual review of medicine
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    [Show abstract] [Hide abstract] ABSTRACT: Background: The four intrinsic subtypes of breast cancer, defined by differential expression of 50 genes (PAM50), have been shown to be predictive of risk of recurrence and benefit of hormonal therapy and chemotherapy. Here we describe the development of Prosigna™, a PAM50-based subtype classifier and risk model on the NanoString nCounter Dx Analysis System intended for decentralized testing in clinical laboratories. Methods: 514 formalin-fixed, paraffin-embedded (FFPE) breast cancer patient samples were used to train prototypical centroids for each of the intrinsic subtypes of breast cancer on the NanoString platform. Hierarchical cluster analysis of gene expression data was used to identify the prototypical centroids defined in previous PAM50 algorithm training exercises. 304 FFPE patient samples from a well annotated clinical cohort in the absence of adjuvant systemic therapy were then used to train a subtype-based risk model (i.e. Prosigna ROR score). 232 samples from a tamoxifen-treated patient cohort were used to verify the prognostic accuracy of the algorithm prior to initiating clinical validation studies. Results: The gene expression profiles of each of the four Prosigna subtype centroids were consistent with those previously published using the PCR-based PAM50 method. Similar to previously published classifiers, tumor samples classified as Luminal A by Prosigna had the best prognosis compared to samples classified as one of the three higher-risk tumor subtypes. The Prosigna Risk of Recurrence (ROR) score model was verified to be significantly associated with prognosis as a continuous variable and to add significant information over both commonly available IHC markers and Adjuvant! Online. Conclusions: The results from the training and verification data sets show that the FDA-cleared and CE marked Prosigna test provides an accurate estimate of the risk of distant recurrence in hormone receptor positive breast cancer and is also capable of identifying a tumor's intrinsic subtype that is consistent with the previously published PCR-based PAM50 assay. Subsequent analytical and clinical validation studies confirm the clinical accuracy and technical precision of the Prosigna PAM50 assay in a decentralized setting.
    Full-text available · Article · Aug 2015 · BMC Medical Genomics
  • Rupert Bartsch · Michael Gnant · Guenther G Steger
    Article · Aug 2015 · The Lancet Oncology
  • [Show abstract] [Hide abstract] ABSTRACT: Neoadjuvant chemotherapy (NACT) is an accepted treatment approach in early-stage breast cancer. In contrast, the potential role of postneoadjuvant chemotherapy after taxane-containing NACT remains unclear. The aim of this study was to evaluate postneoadjuvant chemotherapy and further prognostic factors that predict outcome in women without pathologic complete remission (pCR). A total of 377 patients with breast cancer who received preoperative chemotherapy were included in this retrospective study. Patients without standard NACT (6 cycles of epirubicin with docetaxel) or primary metastatic breast cancer and locally advanced, inoperable cancer were excluded from further analysis (n = 186). This resulted in a study population of 191 women (30 [15.7%] with pCR; 161 [84.3%] without pCR). Major outcome parameters were event-free survival (EFS) and overall survival (OS). The following parameters were tested for their prognostic role: postneoadjuvant chemotherapy, patient age, breast cancer subtype (luminal/HER2-negative tumors, HER2-positive tumors, and triple-negative tumors), histological grade, pCR, residual lymph node invasion, and residual invasive tumor size. At a median follow-up of 54 months, 51 disease relapses (26.7%) and 21 deaths (11%) were observed. In a comparison of patients with pCR with those without, no significant differences in EFS or OS were observed. Postneoadjuvant chemotherapy was significantly associated with shorter OS in patients without pCR. In this population, which included a high percentage of patients with luminal cancers, pCR did not predict for improved OS. Postneoadjuvant chemotherapy showed no discernible benefit even in subgroups with aggressive tumor biology or significant remaining tumor burden. The use of such treatment should therefore be discouraged outside of clinical trials. Copyright © 2015 Elsevier Inc. All rights reserved.
    Article · Jun 2015 · Clinical Breast Cancer
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    [Show abstract] [Hide abstract] ABSTRACT: Breast International Group (BIG) 2-98 is a randomised phase III trial that tested the effect of adding docetaxel, either in sequence to or in combination with anthracycline-based adjuvant chemotherapy, in women with node-positive breast cancer (BC). Here, we present the 10-year final trial safety and efficacy analyses. We also report an exploratory analysis on the predictive value of Ki67 for docetaxel efficacy, in the BIG 2-98 and using a pooled analysis of three other randomised trials. 2887 patients were randomly assigned in a 2×2 trial design to one of four treatments. The primary objective was to evaluate the overall efficacy of docetaxel on disease free survival (DFS). Secondary objectives included comparisons of sequential docetaxel versus sequential control arm, safety and overall survival (OS). Ki67 expression was centrally evaluated by immunohistochemistry. After a median follow-up of 10.1years, the addition of docetaxel did not significantly improve DFS or OS (hazard ratio (HR)=0.91, 95% confidence interval (CI)=0.81-1.04; P=0.16 and HR=0.88, 95% CI=0.76-1.03; P=0.11, respectively). Sequential docetaxel did not improve DFS compared to the sequential control arm (HR=0.86, 95% CI=0.72-1.03; P=0.10). In oestrogen receptor (ER)-positive tumours with Ki67⩾14%, the addition of docetaxel resulted in 5.4% improvement in 10-year OS (P=0.03, test for interaction=0.1). In a multivariate model, there was a trend for improved DFS and OS in ER-positive patients with high Ki67 and treated with docetaxel (HR=0.79, 95% CI=0.63-1.01; P=0.05 and HR=0.76, 95% CI=0.57-1.01; P=0.06, respectively). A pooled analysis of four randomised trials showed a benefit of taxanes in highly proliferative ER-positive disease but not in low proliferating tumours (interaction test P=0.01). The DFS benefit previously demonstrated with sequential docetaxel is no longer observed at 10years. However, an exploratory analysis suggested a benefit of docetaxel in patients with highly proliferative ER-positive BC. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Full-text available · Article · Jun 2015 · European journal of cancer (Oxford, England: 1990)
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    [Show abstract] [Hide abstract] ABSTRACT: We investigated the hypothesis that the varying treatment efficacy of adjuvant 5-fluorouracil (5FU) in stage III colon cancer is linked to the TP53 mutational status. ABCSG-90 was a prospective randomized trial in which effect of adjuvant 5FU was studied in stage III colon cancer patients. Tumor material of 70% of these patients (389/572) was available for analysis of the biomarker TP53 using a TP53-gene-specific Sanger sequencing protocol. Median follow-up was 88 months. TP53 mutation frequency was 33%. A significant interaction between TP53 status, outcomes and nodal category was found (P = 0.0095). In the N1 category, TP53 wildtype patients had significantly better overall survival than TP53 mutated (81.0% vs. 62.0% overall survival at 5 years; HR = 2.131; 95% CI: 1.344–3.378; P = 0.0010). In the N2 category, the TP53 status did not affect survival (P = 0.4992). In TP53 wildtype patients, the prognostic significance of N category was significantly enhanced (P = 0.0002). In TP53 mutated patients, survival curves of N1 and N2 patients overlapped and nodal category was no longer prognostic. The biomarker TP53 independently predicted effect of adjuvant 5FU in N1 colon cancer patients. TP53 was not predictive in N2 patients, in whom 5FU is known to have no effect.
    Full-text available · Article · Jun 2015 · EBioMedicine
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    Michael Gnant · Georg Pfeiler · Peter C Dubsky · [...] · Christian F Singer
    [Show abstract] [Hide abstract] ABSTRACT: Adjuvant endocrine therapy compromises bone health in patients with breast cancer, causing osteopenia, osteoporosis, and fractures. Antiresorptive treatments such as bisphosphonates prevent and counteract these side-effects. In this trial, we aimed to investigate the effects of the anti-RANK ligand antibody denosumab in postmenopausal, aromatase inhibitor-treated patients with early-stage hormone receptor-positive breast cancer. In this prospective, double-blind, placebo-controlled, phase 3 trial, postmenopausal patients with early hormone receptor-positive breast cancer receiving treatment with aromatase inhibitors were randomly assigned in a 1:1 ratio to receive either denosumab 60 mg or placebo administered subcutaneously every 6 months in 58 trial centres in Austria and Sweden. Patients were assigned by an interactive voice response system. The randomisation schedule used a randomly permuted block design with block sizes 2 and 4, stratified by type of hospital regarding Hologic device for DXA scans, previous aromatase inhibitor use, and baseline bone mineral density. Patients, treating physicians, investigators, data managers, and all study personnel were masked to treatment allocation. The primary endpoint was time from randomisation to first clinical fracture, analysed by intention to treat. As an additional sensitivity analysis, we also analysed the primary endpoint on the per-protocol population. Patients were treated until the prespecified number of 247 first clinical fractures was reached. This trial is ongoing (patients are in follow-up) and is registered with the European Clinical Trials Database, number 2005-005275-15, and with ClinicalTrials.gov, number NCT00556374. Between Dec 18, 2006, and July 22, 2013, 3425 eligible patients were enrolled into the trial, of whom 3420 were randomly assigned to receive denosumab 60 mg (n=1711) or placebo (n=1709) subcutaneously every 6 months. Compared with the placebo group, patients in the denosumab group had a significantly delayed time to first clinical fracture (hazard ratio [HR] 0·50 [95% CI 0·39-0·65], p<0·0001). The overall lower number of fractures in the denosumab group (92) than in the placebo group (176) was similar in all patient subgroups, including in patients with a bone mineral density T-score of -1 or higher at baseline (n=1872, HR 0·44 [95% CI 0·31-0·64], p<0·0001) and in those with a bone mineral density T-score of less than -1 already at baseline (n=1548, HR 0·57 [95% CI 0·40-0·82], p=0·002). The patient incidence of adverse events in the safety analysis set (all patients who received at least one dose of study drug) did not differ between the denosumab group (1366 events, 80%) and the placebo group (1334 events, 79%), nor did the numbers of serious adverse events (521 vs 511 [30% in each group]). The main adverse events were arthralgia and other aromatase-inhibitor related symptoms; no additional toxicity from the study drug was reported. Despite proactive adjudication of every potential osteonecrosis of the jaw by an international expert panel, no cases of osteonecrosis of the jaw were reported. 93 patients (3% of the full analysis set) died during the study, of which one death (in the denosumab group) was thought to be related to the study drug. Adjuvant denosumab 60 mg twice per year reduces the risk of clinical fractures in postmenopausal women with breast cancer receiving aromatase inhibitors, and can be administered without added toxicity. Since a main side-effect of adjuvant breast cancer treatment can be substantially reduced by the addition of denosumab, this treatment should be considered for clinical practice. Amgen. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Full-text available · Article · May 2015 · The Lancet

Publication Stats

10k Citations


  • 2014
    • Medical University of Vienna
      Wien, Vienna, Austria
  • 2013
    • IST Austria
      Klosterneuberg, Lower Austria, Austria
    • Medical University of Graz
      Gratz, Styria, Austria
  • 2012
    • Johannes Gutenberg-Universität Mainz
      Mayence, Rheinland-Pfalz, Germany
    • University of California, San Francisco
      San Francisco, California, United States
    • University of Toronto
      Toronto, Ontario, Canada
  • 2007-2012
    • Paracelsus Medical University Salzburg
      Salzburg, Salzburg, Austria
  • 2009-2010
    • Vienna General Hospital
      Wien, Vienna, Austria