Wolfgang J. Köstler

Oral Mucositis Complicating Chemotherapy and/or Radiotherapy: Options for Prevention and Treatment†

Chemotherapy‐ and radiotherapy‐induced oral mucositis represents a therapeutic challenge frequently encountered in cancer patients. This side effect causes significant morbidity and may delay the treatment plan, as well as increase therapeutic expenses.

Monitoring of serum Her-2/neu predicts response and progression-free survival to trastuzumab-based treatment in patients with metastatic breast cancer

Purpose: The present pilot study was performed to elucidate whether early changes in serum Her-2/neu extracellular domain (ECD) levels during trastuzumab-based treatment would predict the clinical course of disease in patients with metastatic breast cancer. Experimental Design: Sera from 55 patients with Her-2/neu-overexpressing metastatic breast cancer obtained immediately before each weekly administration of trastuzumab were analyzed by a serum Her-2/neu ELISA. Results: Whereas response rates were significantly higher in patients with elevated (≥15 ng/ml) ECD levels before initiation of treatment (35% versus 7%, P = 0.045), progression-free and overall survival did not differ significantly between patients with normal and elevated ECD levels. In patients responding to treatment, ECD levels decreased significantly as early as from day 8 of treatment onwards (all P for weekly measurements versus baseline <0.001). In contrast, no significant change in ECD levels was observed in patients with progressive disease. Multiple logistic regression analyses identified kinetics of ECD levels as the only factor that allowed for the accurate prediction of response likelihood as early as from day 8 of trastuzumab-based treatment onwards (P = 0.020). In addition, determination of serial ECD levels allowed for the prediction of the risk for disease progression within the observed period as early as day 15 of treatment (P = 0.010). Conclusions: Serial monitoring of the ECD may represent a valuable tool for early prediction of the probability of response and progression-free survival to trastuzumab-based treatment and is thus likely to contribute to an optimization of treatment and resource allocation.

Trastuzumab has preferential activity against breast cancers driven by HER2 homodimers

In breast cancer cells with HER2 gene amplification, HER2 receptors exist on the cell surface as monomers, homodimers, and heterodimers with EGFR/HER3. The therapeutic antibody trastuzumab, an approved therapy for HER2(+) breast cancer, cannot block ligand-induced HER2 heterodimers, suggesting it cannot effectively inhibit HER2 signaling. Hence, HER2 oligomeric states may predict the odds of a clinical response to trastuzumab in HER2-driven tumors. To test this hypothesis, we generated nontransformed human MCF10A mammary epithelial cells stably expressing a chimeric HER2-FKBP molecule that could be conditionally induced to homodimerize by adding the FKBP ligand AP1510, or instead induced to heterodimerize with EGFR or HER3 by adding the heterodimer ligands EGF/TGFα or heregulin. AP1510, EGF, and heregulin each induced growth of MCF10A cells expressing HER2-FKBP. Trastuzumab inhibited homodimer-mediated but not heterodimer-mediated cell growth. In contrast, the HER2 antibody pertuzumab, which blocks HER2 heterodimerization, inhibited growth induced by heregulin but not AP1510. Lastly, the HER2/EGFR tyrosine kinase inhibitor lapatinib blocked both homodimer- and heterodimer-induced growth. AP1510 triggered phosphorylation of Erk1/2 but not AKT, whereas trastuzumab inhibited AP1510-induced Erk1/2 phosphorylation and Shc-HER2 homodimer binding, but not TGFα-induced AKT phosphorylation. Consistent with these observations, high levels of HER2 homodimers correlated with longer time to progression following trastuzumab therapy in a cohort of patients with HER2-overexpressing breast cancer. Together, our findings confirm the notion that HER2 oligomeric states regulate HER2 signaling, also arguing that trastuzumab sensitivity of homodimers may reflect their inability to activate the PI3K (phosphoinositide 3-kinase)/AKT pathway. A clinical implication of our results is that high levels of HER2 homodimers may predict a positive response to trastuzumab.

Quantitation of p95HER2 in Paraffin Sections by Using a p95-Specific Antibody and Correlation with Outcome in a Cohort of Trastuzumab-Treated Breast Cancer Patients

Purpose: p95HER2 is an NH2-terminally truncated form of HER2 that lacks the trastuzumab binding site and is therefore thought to confer resistance to trastuzumab treatment. In this report, we introduce a new antibody that has enabled the first direct quantitative measurement of p95HER2 in formalin-fixed paraffin-embedded (FFPE) breast cancer tissues. We sought to show that quantitative p95HER2 levels would correlate with outcome in trastuzumab-treated HER2-positive metastatic breast cancer. Experimental Design: The novel p95HER2 antibody used here was characterized for sensitivity, specificity, and selectivity over full-length HER2. Quantitative p95HER2 levels were measured in 93 metastatic breast tumors using a VeraTag FFPE assay to determine the correlation of p95HER2 levels with outcomes. Results: Within a cohort of trastuzumab-treated metastatic breast cancer patients, high levels of p95HER2 were found to correlate with shorter progression-free survival [hazard ratio (HR), 1.9; P = 0.017] and overall survival (HR, 2.2; P = 0.012) in patients with tumors selected to be HER2 positive by the VeraTag HER2 assay. For those with tumors found to be fluorescence in situ hybridization positive, elevated p95HER2 correlated similarly with shorter progression-free survival (HR, 1.8; P = 0.022) and overall survival (HR, 2.2; P = 0.009). Conclusions: We have successfully generated an antibody that can specifically detect p95HER2, and developed an assay to quantify expression in FFPE tumor specimens. Using this novel assay, we have identified a group of HER2-positive patients expressing p95HER2 that have a worse outcome while on trastuzumab. As p95HER2 retains sensitivity to kinase inhibitors, measurement of p95HER2 in breast tumor sections may be useful in guiding treatment for patients with HER2-positive breast cancer. Clin Cancer Res; 16(16); 4226–35. ©2010 AACR.

Serum HER‐2/neu and relative resistance to trastuzumab‐based therapy in patients with metastatic breast cancer

Previous reports based on small patient numbers suggested that changes in serum HER‐2/neu levels may predict response or lack of response to trastuzumab‐based therapies in metastatic breast cancer (MBC). The objectives of this study were to pool data from 307 patients with MBC from 7 medical institutions to validate that the serum HER‐2/neu profile predicts patient resistance to trastuzumab and to establish a clinically relevant cutoff.

Decrease of duration and symptoms in chemotherapy-induced oral mucositis by topical GM-CSF: results of a prospective randomised trial.

We have conducted a prospective controlled randomised clinical study testing for the efficacy of topical GM-CSF (molgramostim), as compared to the combined topical use of an antiseptic agent (povidone-iodine) and amphotericin B (AA) in patients with chemotherapy-induced mucositis World Health Organization (WHO) grades I-III. 31 patients (17 females, 14 males) developing oral mucositis following the administration of 5-fluorouracil (5-FU)-based chemotherapy were entered into the present trial. 15 patients were randomised to receive GM-CSF mouthwashes, whereas 16 patients were randomised into the control arm to receive AA. Reported history (P=0.6109) and grading of oral mucositis (2.1+/-0.7, respectively; P=0.9867) were balanced and equally distributed between the two groups. The mean size of lesions of oral mucositis was 1.5+/-0.6 cm (range: 0.7-2.5 cm) in the GM-CSF group and 1.2+/-0.5 cm (range: 0.5-2.5 cm) in the AA group (P=0.08), respectively. The mean number of oral mucositis lesions was 1.9+/-1.1 (range: 1-4) in the GM-CSF group and 2.1+/-1.2 (range: 1-4) in the AA group (P=0.63), respectively. None of the patients had previously received colony stimulating factors either topically or systemically. Treatment for oral mucositis was initiated on day 2.7+/-1.2 (range: day 1-8) after onset of symptoms in the GM-CSF group and on day 1.8+/-1.4 (range: day 1-3; P=0.11) in the AA group. The topical application of GM-CSF resulted in a significantly shorter duration and quicker resolution of oral mucositis, as compared to AA including both, pretreatment plus treatment periods (5.3+/-2.5 versus 8.1+/-1.5 days; P=0.0008) as well as the necessary duration of treatment needed until complete remission of lesions (2.8+/-0.7 versus 6.3+/-1.1 days; P<0.0001). A systemic effect of topical GM-CSF upon the number of peripheral blood leukocytes or granulocytes was excluded. We conclude that the topical application of GM-CSF by mouthwash significantly abbreviated the duration and relieved patients from symptoms of chemotherapy-induced mucositis and was superior to the topical application of AA.

Her-2/ neu- triggered intracellular tyrosine kinase activation: in vivo relevance of ligand-independent activation mechanisms and impact upon the efficacy of trastuzumab-based treatment

Proteolytic cleavage of the Her-2/neu extracellular domain (ECD) has been shown to initiate receptor phosphorylation representing Her-2/neu activation in vitro. The present investigation was performed to evaluate the clinical relevance of ECD cleavage for Her-2/neu activation and the consequences of active intracellular Her-2/neu signalling reflected by tyrosine kinase phosphorylation in patients treated with the anti-Her-2/neu antibody trastuzumab. Sera from 62 patients receiving trastuzumab-based treatment for Her-2/neu overexpressing metastatic breast cancer were assessed for pretreatment ECD levels using an enzyme-linked immunosorbent assay. In parallel, Her-2/neu activation status of tumour specimens was assessed by immunohistochemistry using a Her-2/neu phosphorylation state specific antibody (PN2A) and correlated with the patients’ ECD levels and clinical course of disease. Serum ECD levels were significantly higher in 15 (24%) patients with tumours exhibiting activated Her-2/neu as compared to those without detectable Her-2/neu phosphorylation (median 148.2 vs 28.5 ng ml−1, P=0.010). Whereas response rate only showed a trend to be higher in patients with Her-2/neu-phosphorylated breast cancer (47 vs 34%, P=0.197), both uni- and multivariate analyses revealed that the median progression-free survival under trastuzumab-based treatment was significantly longer in patients with Her-2/neu-phosphorylated breast cancer–11.7 (95% CI 5.2–18.3) months–when compared to the progression-free survival of 4.5 (95% CI 3.4–5.6) months observed in patients with tumours lacking phosphorylated Her-2/neu (P=0.001). Proteolytic cleavage of the ECD represents a biologically relevant ligand-independent mechanism of Her-2/neu activation in vivo. The influence of Her-2/neu activation status upon the outcome of trastuzumab-based therapies merits further investigation in larger prospective trials.

Cardiovascular biomarkers in patients with cancer and their association with all-cause mortality

Objective Patients with cancer may display elevated levels of B-type natriuretic peptide (BNP) and high-sensitive troponin T (hsTnT) without clinical manifestation of cardiac disease. This study aimed to evaluate circulating cardiovascular hormones and hsTnT and their association with mortality in cancer. Methods We prospectively enrolled 555 consecutive patients with a primary diagnosis of cancer and without prior cardiotoxic anticancer therapy. N-terminal pro BNP (NT-proBNP), mid-regional pro-atrial natriuretic peptide (MR-proANP), mid-regional pro-adrenomedullin (MR-proADM), C-terminal pro-endothelin-1 (CT-proET-1), copeptin, hsTnT, proinflammatory markers interleukin 6 (IL-6) and C reactive protein (CRP), and cytokines serum amyloid A (SAA), haptoglobin and fibronectin were measured. All-cause mortality was defined as primary endpoint. Results During a median follow-up of 25 (IQR 16–31) months, 186 (34%) patients died. All cardiovascular hormones and hsTnT levels rose with tumour stage progression. All markers were significant predictors of mortality with HRs per IQR of 1.54 (95% CI 1.24 to 1.90, p<0.001) for NT-proBNP, 1.40 (95% CI 1.10 to 1.79, p<0.01) for MR-proANP, 1.31 (95% CI 1.19 to 1.44, p<0.001) for MR-proADM, 1.21 (95% CI 1.14 to 1.30, p<0.001) for CT-proET-1, 1.22 (95% CI 1.04 to 1.42, p=0.014) for copeptin and 1.21 (95% CI 1.13 to 1.32, p<0.001) for hsTnT, independent of age, gender, tumour entity and stage, and presence of cardiac comorbidities. NT-proBNP, MR-proANP, MR-proADM and hsTnT displayed a significant correlation with IL-6 and CRP. Conclusions Circulating levels of cardiovascular peptides like NT-proBNP, MR-proANP, MR-proADM, CT-pro-ET-1 and hsTnT were elevated in an unselected population of patients with cancer prior to induction of any cardiotoxic anticancer therapy. The aforementioned markers and copeptin were strongly related to all-cause mortality, suggesting the presence of subclinical functional and morphological myocardial damage directly linked to disease progression.

Comparison of Mucosal Pressures Induced by Cuffs of Different Airway Devices

Background:High pressures exerted by balloons and cuffs of conventional endotracheal tubes, the Combitube® (Tyco Healthcare Nellcor Mallinckrodt, Pleasanton, CA), the EasyTube® (Teleflex Ruesch, Kernen, Germany), the Laryngeal Mask Airway ™ (LMA North America, San Diego, CA), the Intubating Laryngeal Mask Airway ™ (Fastrach®; LMA North America), the ProSeal ™ (LMA North America), and the Laryngeal Tube (LT; VBM Medizintechnik, Sulz, Germany) may traumatize the pharyngeal mucosa. The aim of this study was to compare pressures exerted on the pharyngeal, tracheal, and esophageal mucosa by different devices designed for securing the patient’s airways. Methods:Nineteen fresh cadavers were included. To measure mucosal pressures, microchip sensors were fixed on the anterior, lateral, and posterior surfaces of the proximal balloon and the distal cuff of the investigated devices. Depending on the respective airway device, the cuff volume was increased in 10-ml increments at the proximal balloon starting from 0 to a maximum of 100 ml, and in 2-ml increments at the distal cuff starting from 0 up to 12 ml. Results:Tracheal mucosal pressures were significantly higher using the Combitube® compared with the endotracheal tube and the EasyTube®. Maximal esophageal pressures were significantly higher using the EasyTube® compared with the Combitube®. Using cuff volumes according to the manufacturers’ guidelines, we found the highest pharyngeal pressures with the Intubating Laryngeal Mask Airway ™ versus all other devices. At maximal volumes, the Laryngeal Mask Airway ™, the Intubating Laryngeal Mask Airway ™, and the ProSeal ™ induced significantly higher pharyngeal pressures compared with all other devices. Using a pharyngeal cuff volume of 40 ml, the Intubating Laryngeal Mask Airway ™ followed by the Laryngeal Mask Airway ™ exerted significantly higher pressures compared with the other devices. Conclusions:Although some devices exhibit a somewhat higher mucosal pressure when compared with others, the authors believe that the observed differences of the cuff pressures do not suggest a clinically relevant danger, because the investigated devices, except the endotracheal tubes, are not intended for prolonged use.

Closed Suctioning System Reduces Cross-Contamination Between Bronchial System and Gastric Juices

In this prospective, randomized study, we evaluated whether a closed suctioning (CS) system (TrachCare) influences crossover contamination between bronchial system and gastric juices when compared with an open suctioning system (OS). The secondary aims were an analysis of the frequency of ventilator-associated pneumonia (VAP) and an analysis of alteration in gas exchange. Antibiograms were performed from tracheal secretions and gastric juice aspirates on Days 1 and 3 of intubation in 24 patients in a medical intensive care unit. Five cross-contaminations were observed in the OS group on Day 3 versus Day 1; the 5 strains shared common genotypes as determined by random amplification of polymorphic DNA. No cross-contaminations were seen in the CS group (P = 0.037). VAP occurred in 5 patients of the OS group but in none of the CS group patients (P = 0.037). Spao(2) decreased significantly in the OS group compared with presuctioning values--the opposite of the CS group. Whereas presuctioning values were comparable between groups, postsuctioning Spao(2) was significantly higher in the CS group. CS significantly reduced cross-contamination between bronchial system and gastric juices and reduced the incidence of VAP when compared with OS. Hypoxic phases can be reduced by the help of CS.