Surgical treatment of displaced proximal humeral fractures with use of the locking proximal humeral plate that was evaluated in the present study can lead to a good functional outcome provided that the correct surgical technique is used. Because many of the complications were related to incorrect surgical technique, it behooves the treating surgeon to perform the operation correctly to avoid iatrogenic errors.

The incidence and severity of oral mucositis is influenced by the type of antineoplastic treatment administered and by patient-related factors. Severe courses of oral mucositis are observed during simultaneous radiochemotherapy, which Oral Mucositis Complicating Chemotherapy and/or Radiotherapy: Options for Prevention and TreatmentWolfgang J. Köstler, MD; Michael Hejna, MD; Catharina Wenzel, MD; and Christoph C. Zielinski, MD 290 CA A Cancer Journal for Clinicians ABSTRACT 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.The pathogenesis of this debilitating side effect can be attributed to the direct mucosal toxicity of cytotoxic agents and ionizing radiation and to indirect mucosal damage caused by a concomitant inflammatory reaction exacerbated in the presence of neutropenia, and the emergence of bacterial, mycotic, and viral infections. affects virtually all patients with head and neck cancer who receive this therapeutic modality. 8 However, up to 40% of patients treated with conventional chemotherapy and the more than 70% of patients undergoing conditioning therapy for bone marrow transplantation also experience oral treatment-related complications. 9,10The pathogenesis of oral mucositis is not fully understood, yet it is thought to involve direct and indirect mechanisms. Direct mucosal injury by radiation and chemotherapy interfere with the average 5-to 14-day turnover time of the oral epithelium 11 and induce apoptosis. Indirect stomatotoxic effects that result from the release of inflammatory mediators, loss of protective salivary constituents, and therapyinduced neutropenia have been postulated to contribute to the development of oral mucositis and also promote the emergence of bacteria, fungi, and viruses on damaged mucosa.12 Although a linear relationship among the occurrence of oral mucositis, oral and systemic granulocyte counts, and a coincidence of resolution of mucositis with neutrophil recovery, has been demonstrated, 10,[13][14][15] significant mucositis can occur in the absence of myelotoxicity. 16,17 In addition, the prophylactic or therapeutic elimination of the pathogenic mucosal flora frequently observed in patients developing oral mucositis by various antiseptic and antimicrobial agents can at most alleviate the course of oral mucositis (see Antimicrobal Agents p. 302).Based upon these considerations, newer pathophysiologic concepts have emerged characterizing oral mucositis as having an initial inflammatory/vascular phase, an epithelial phase, a (pseudomembraneous) ulcerative/bacteriological phase and a healing phase.18 During the inflammatory phase, tissue injury induces release of free radicals, modified proteins and proinflammatory cytokines including interleukin-1β, prostaglandins and tumor necrosis factor-α (TNF-α) by epithelial, endothelial, and connective tissue cells. These ...

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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 non-transformed 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. As expected, 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, 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 HER2-overexpressing patients. Together, our findings corroborate the hypothesis that HER2 oligomeric states regulate HER2 signaling, also arguing that trastuzumab sensitivity of homodimers reflects an inability to activate the PI3K/AKT pathway. One of the most important clinical implications of our results is that high levels of HER2 homodimers may predict a positive response to trastuzumab.

Genome-wide simultaneous measurements of pre-mRNA and mRNA expression reveal unexpected time-dependent transcript production and degradation profiles in response to external stimulus, as well as a striking lack of concordance between mRNA abundance and transcript production profiles.

Purpose: p95HER2 is an NH 2 -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.

Edited by Stefan HohmannKeywords: EGFR Mutations Kinase Lung cancer Glioblastoma ErbB a b s t r a c tThe EGF-receptor is frequently mutated in a large variety of tumors. Here we review the most frequent mutations and conclude that they commonly enhance the intrinsic tyrosine kinase activity, or they represent loss-of-function of suppressive regulatory domains. Interestingly, the constitutive activity of mutant receptors translates to downstream pathways, which are subtly different from those stimulated by the wild-type receptor. Cancer drugs intercepting EGFR signaling have already entered clinical application. Both kinase inhibitors specific to EGFR, and monoclonal antibodies to the receptor are described, along with experimental approaches targeting the HSP90 chaperone. Deeper understanding of signaling pathways downstream to mutant receptors will likely improve the outcome of current EGFR-targeted therapies, as well as help develop new drugs and combinations.