Holger W. Auner

Two transforming C-RAF germ-line mutations identified in patients with therapy-related acute myeloid leukemia.

Mutations leading to activation of the RAF-mitogen-activated protein kinase/extracellular signal-regulated (ERK) kinase (MEK)-ERK pathway are key events in the pathogenesis of human malignancies. In a screen of 82 acute myeloid leukemia (AML) samples, 45 (55%) showed activated ERK and thus were further analyzed for mutations in B-RAF and C-RAF. Two C-RAF germ-line mutations, S427G and I448V, were identified in patients with therapy-related AML in the absence of alterations in RAS and FLT3. Both exchanges were located within the kinase domain of C-RAF. In vitro and in vivo kinase assays revealed significantly increased activity for (S427G)C-RAF but not for (I448V)C-RAF. The involvement of the S427G C-RAF mutation in constitutive activation of ERK was further confirmed through demonstration of activating phosphorylations on C-RAF, MEK, and ERK in neoplastic cells, but not in nonneoplastic cells. Transformation and survival assays showed oncogenic and antiapoptotic properties for both mutations. Screening healthy individuals revealed a <1/400 frequency of these mutations and, in the case of I448V, inheritance was observed over three generations with another mutation carrier suffering from cancer. Taken together, these data are the first to relate C-RAF mutations to human malignancies. As both mutations are of germ-line origin, they might constitute a novel tumor-predisposing factor.

Optimizing patient selection for myeloablative allogeneic hematopoietic cell transplantation in chronic myeloid leukemia in chronic phase

Outstanding results have been obtained in the treatment of chronic myeloid leukemia (CML) with first-line imatinib therapy. However, approximately 35% of patients will not obtain long-term benefit with this approach. Allogeneic hematopoietic stem cell transplantation (HCT) is a valuable second- and third-line therapy for appropriately selected patients. To identify useful prognostic indicators of transplantation outcome in postimatinib therapeutic interventions, we investigated the role of the HCT comorbidity index (HCT-CI) together with levels of C-reactive protein (CRP) before HCT in 271 patients who underwent myeloablative HCT for CML in first chronic phase. Multivariate analysis showed both an HCT-CI score higher than 0 and CRP levels higher than 9 mg/L independently predict inferior survival and increased nonrelapse mortality at 100 days after HCT. CML patients without comorbidities (HCT-CI score 0) with normal CRP levels (0-9 mg/L) may therefore be candidates for early allogeneic HCT after failing imatinib.

Trends in autologous hematopoietic cell transplantation for multiple myeloma in Europe: increased use and improved outcomes in elderly patients in recent years

Autologous hematopoietic cell transplantation (AHCT) is a standard of care in multiple myeloma (MM) patients aged <65 years. To understand age-related trends in utilisation and outcome of AHCT, we analysed 53 675 MM patients who underwent a first AHCT in 31 European countries between 1991 and 2010. The number of patients undergoing AHCT increased for all age groups (<40, 40–49, 50–59, 60–64, 65–69 and ⩾70 years) throughout the observation period. The highest increase was observed for patients aged ⩾65 years, who accounted for 3% of AHCTs in 1991–1995 and for 18.8% of AHCTs in 2006–2010. Risk factors associated with survival over the entire observation period (P<0.001) were calendar period, remission status at AHCT, gender, disease duration before AHCT and age. Survival improved considerably more in older than in younger patients in recent years. In 2006–2010, median 2- and 5-year post-transplant survival ranged from 85.9 and 61.5% in patients <40 years to 80.2 and 49.7% in those ⩾70 years. All-cause day-100 mortality decreased throughout the observation period to ⩽2.4% for all age groups in 2006–2010. The results of this study demonstrate increased utilisation and safety of AHCT with improved post-transplant survival particularly in elderly MM patients in recent years in Europe.

A novel role for the Aurora B kinase in epigenetic marking of silent chromatin in differentiated postmitotic cells

Combinatorial modifications of the core histones have the potential to fine‐tune the epigenetic regulation of chromatin states. The Aurora B kinase is responsible for generating the double histone H3 modification tri‐methylated K9/phosphorylated S10 (H3K9me3/S10ph), which has been implicated in chromosome condensation during mitosis. In this study, we have identified a novel role for Aurora B in epigenetic marking of silent chromatin during cell differentiation. We find that phosphorylation of H3 S10 by Aurora B generates high levels of the double H3K9me3/S10ph modification in differentiated postmitotic cells and also results in delocalisation of HP1β away from heterochromatin in terminally differentiated plasma cells. Microarray analysis of the H3K9me3/S10ph modification shows a striking increase in the modification across repressed genes during differentiation of mesenchymal stem cells. Our results provide evidence that the Aurora B kinase has a role in marking silent chromatin independently of the cell cycle and suggest that targeting of Aurora B‐mediated phosphorylation of H3 S10 to repressed genes could be a mechanism for epigenetic silencing of gene expression.

Pulmonary infiltrates in patients with haematologic malignancies: transbronchial lung biopsy increases the diagnostic yield with respect to neoplastic infiltrates and toxic pneumonitis

We retrospectively evaluated 107 fiberoptic bronchoscopies with and without transbronchial lung biopsy (TBLB) in 98 consecutive patients with haematologic malignancies and pulmonary infiltrates. Bronchoalveolar lavage (BAL) was performed in 45 and BAL plus TBLB in 62 procedures. There was no procedure-related severe haemorrhage, pneumothorax or death. Infectious aetiology was identified in 26 of 107 (24%), toxic pneumonitis in 17 of 107 (16%) and neoplastic infiltration in 9 of 107 (8.5%) episodes. Combined BAL and TBLB was significantly superior to BAL alone with respect to the diagnosis of neoplastic infiltrates (p=0.008) and toxic pneumonitis (p<0.001) and should therefore be included in the diagnostic work-up of this patient cohort.

Monitoring of cardiac function by serum cardiac troponin T levels, ventricular repolarisation indices, and echocardiography after conditioning with fractionated total body irradiation and high-dose cyclophosphamide

Abstract: Objectives : Highly differing rates of cardiac complications associated with high‐dose cyclophosphamide (CY) have been reported, and only one clinical study has been performed on the cardiotoxic effects of CY monotherapy following total body irradiation (TBI). Patients and methods : We prospectively evaluated the potential cardiotoxic effects of conditioning with fractionated total body irradiation and high‐dose cyclophosphamide (TBI/CY) by serial measurement of serum cardiac troponin T (cTnT), assessment of systolic and diastolic echocardiographic parameters and analysis of ventricular repolarisation indices (QT‐dispersion and corrected QT‐dispersion) in 30 adult patients with haematological malignancies undergoing haematopoietic stem cell transplantation. Results: There was no evidence of pretreatment cardiac dysfunction in any patient. Although cTnT was determined serially for a median of 14 d after completion of conditioning, no elevated levels were observed. Echocardiographic parameters did not show any significant change at a median follow‐up of 5 months except for one patient with evidence of impaired diastolic filling. No significant differences for mean values before and after high‐dose CY were noted for ventricular repolarisation indices. Two patients had a significant increase in corrected QT‐dispersion after CY without any other signs of cardiotoxicity. Congestive heart failure or arrythmias were not observed. Conclusions : These data suggest that TBI/CY is safe with respect to cardiotoxicity in patients without pre‐existing cardiac dysfunction. Hitherto unknown synergistic cardiotoxic effects of CY with other cytostatic drugs may constitute the major pathogenic factor of myocardial dysfunction after high‐dose chemotherapy.

Antimicrobial therapy of febrile complications after high-dose chemo-/radiotherapy and autologous hematopoietic stem cell transplantation

Infectious complications occur in 60–100% of patients following high-dose chemotherapy (HDC) and autologous hematopoietic stem cell transplantation (HSCT), and are commonly caused by Gram-negative aerobic bacteria (such as Pseudomonas aeruginosa and enterobacteriaceae) and Gram-positive cocci (such as enterococci, streptococci and staphylococci), which should be covered by empiric first-line antibiotic therapy. Less frequently, infections are caused by fungi and anaerobic bacteria, and initial therapy does not necessarily have to cover coagulase-negative staphylococci, oxacillin-resistant S. aureus (MRSA), anaerobic bacteria and fungi. Patients who already receive antibiotics and develop pulmonary infiltrates should immediately be treated with systemic antifungals. Patients with fever and diarrhea or other signs and symptoms of gastrointestinal or perianal infection should be treated with antibiotics covering anaerobic bacteria and enterococci. Clinically stable patients with skin infections or central venous catheter-related infections can be treated with standard empiric antibiotic therapy including a beta-lactam active against Pseudomonas aeruginosa with or without an aminoglycoside, and should only receive glycopeptides if they do not respond to first-line therapy within 72 hours, become clinically unstable, have severe mucositis, or when resistance against the empiric antibiotics is demonstrated. Recombinant hematopoietic growth factors should not be added routinely but may be considered in life-threatening situations such as invasive pulmonary mycoses or sepsis.

Reduced intensity-conditioned allogeneic stem cell transplantation for multiple myeloma relapsing or progressing after autologous transplantation: a study by the European Group for Blood and Marrow Transplantation.

Outcomes and prognostic factors of reduced intensity-conditioned allo-SCT (RIC allo-SCT) for multiple myeloma (MM) relapsing or progressing after prior autologous (auto)-SCT are not well defined. We performed an analysis of 413 MM patients who received a related or unrelated RIC allo-SCT for the treatment of relapse/progression after prior auto-SCT. Median age at RIC allo-SCT was 54.1 years, and 44.6% of patients had undergone two or more prior auto-SCTs. Median OS and PFS from the time of RIC allo-SCT for the entire population were 24.7 and 9.6 months, respectively. Cumulative non-relapse mortality (NRM) at 1 year was 21.5%. In multivariate analysis, CMV seronegativity of both patient and donor was associated with significantly better PFS, OS and NRM. Patient–donor gender mismatch was associated with better PFS, fewer than two prior auto-SCT was associated with better OS, and shorter time from the first auto-SCT to the RIC allo-SCT was associated with lower NRM. The results of this study identify patient and donor CMV seronegativity as the key prognostic factor for outcome after RIC allo-SCT for MM relapsing or progressing after prior auto-SCT.

Recent advances and future directions in targeting the secretory apparatus in multiple myeloma

Multiple myeloma is a genetically heterogeneous tumour of transformed plasma cells, terminally differentiated effectors of the B cell lineage specialized in producing large amounts of immunoglobulins. The uniquely well‐developed secretory apparatus that equips normal and transformed plasma cells with the capacity for high‐level protein secretion constitutes a distinctive therapeutic target. In this review we discuss how fundamental cellular processes, such as the unfolded protein response (UPR), endoplasmic reticulum (ER)‐associated degradation and autophagy, maintain intracellular protein homeostasis (proteostasis) and regulate plasma cell ontogeny and malignancy. We summarize our current understanding of the cellular effects of proteasome inhibitors and the molecular bases of resistance to them. Furthermore, we discuss how improvements in our understanding of the secretory apparatus and of the complex interactions between intracellular protein synthesis and degradation pathways can disclose novel drug targets for multiple myeloma, defining a paradigm of general interest for cancer biology and disorders of altered proteostasis.

Salvage autologous stem cell transplantation for multiple myeloma relapsing or progressing after up-front autologous transplantation.

Abstract Progression or relapse occurs in the vast majority of patients with multiple myeloma (MM) who undergo up-front autologous hematopoietic cell transplantation (AHCT1), which remains a cornerstone of treatment in the era of novel agents. Limited data are available regarding the value of salvage therapy with a second AHCT (AHCT2) in patients who relapse/progress after AHCT1. We analyzed the outcome of 83 patients who underwent salvage AHCT2 between 1994 and 2011. Most patients (77%) had received treatment with novel agents between AHCT1 and AHCT2, and 28% of patients were from ethnic minority groups. Median overall survival (OS) from AHCT2 was 31.5 months (95% confidence interval [CI]: 22–41), and median progression-free survival (PFS) was 15.5 months (95% CI: 11–20). In multivariate analysis, only disease status (≥ PR) at AHCT2 was associated with better OS. The 3-year OS rates for patients receiving AHCT2 in > PR and PR were 85.9% (95% CI: 61–96) and 51.3% (95% CI: 34–68), respectively. Disease status at AHCT2 and time to progression/relapse after AHCT1 were associated with PFS in multivariate analysis. In summary, salvage AHCT2 is an effective treatment option in patients with chemosensitive relapse/progression and prolonged remission after a prior autograft.