Piers Blombery

Detection of BRAF mutations in patients with hairy cell leukemia and related lymphoproliferative disorders.

Hairy cell leukemia has been shown to be strongly associated with the BRAF V600E mutation. We screened 59 unenriched archived bone marrow aspirate and peripheral blood samples from 51 patients with hairy cell leukemia using high resolution melting analysis and confirmatory Sanger sequencing. The BRAF V600E mutation was detected in 38 samples (from 36 patients). The BRAF V600E mutation was detected in all samples with disease involvement above the limit of sensitivity of the techniques used. Thirty-three of 34 samples from other hematologic malignancies were negative for BRAF mutations. A BRAF K601E mutation was detected in a patient with splenic marginal zone lymphoma. Our data support the recent finding of a disease defining point mutation in hairy cell leukemia. Furthermore, high resolution melting with confirmatory Sanger sequencing are useful methods that can be employed in routine diagnostic laboratories to detect BRAF mutations in patients with hairy cell leukemia and related lymphoproliferative disorders.

Reactivation of DNA viruses in association with histone deacetylase inhibitor therapy: a case series report

Histone deacetylase inhibitors are a class of anti-cancer agents that induce growth arrest, differentiation, and apoptotic cell death of transformed cells. The authors report three instances of DNA viral reactivation in patients treated with romidepsin on a multicenter phase II trial in patients with cutaneous T-cell lymphoma and peripheral T-cell lymphomas. These observations suggest that vigilance for DNA virus reactivation is needed to quantify the risk in patients treated with histone deacetylase inhibitors. Histone deacetylase inhibitors are a class of anti-neoplastic agents that induce growth arrest, differentiation, and/or apoptotic cell death of transformed cells in vitro and in vivo. A phase II study exploring the efficacy of romidepsin, an histone deacetylase inhibitor, in patients with cutaneous or peripheral T-cell lymphomas was initiated at the National Cancer Institute. To date, over 120 patients with T-cell lymphoma have been treated on a multi-institutional phase II trial of romidepsin. Reactivation of latent DNA viruses including EBV, HBV, and VZV is well described as a consequence of the immune suppression associated with systemic chemotherapy. The incidence of viral reactivation in patients treated with histone deacetylase inhibitors is not yet known. We report the observation of EBV-associated illnesses in 2 patients and the reactivation of HBV in an additional patient treated with romidepsin. These cases may represent reactivation of DNA viruses due to histone deacetylase inhibitor induced immunosuppression, or direct promotion of viral replication via histone deacetylase inhibitor induced chromatin remodeling, or, alternatively, may be related to the underlying disease process. These observations suggest that vigilance for DNA virus reactivation is needed to quantify the risk in patients treated with histone deacetylase inhibitors.

Erdheim-Chester Disease Harboring the BRAF V600E Mutation

Introduction Erdheim-Chester disease (ECD) is a rare, non-Langerhans histiocytosis characterized by xanthogranulomatous infiltration of numerous tissues (in particular, bone, orbits, heart, and retroperitoneum). ECD is associated with an aggressive disease course that is resistant to treatment and has a poor prognosis. The pathogenesis of ECD remains poorly understood, and evidence regarding the clonal basis of ECD has been conflicting. In this article, we describe a patient with ECD harboring a BRAF V600E mutation, which has important therapeutic implications for the patient and provides insight into the biologic basis of the disease itself.

Whole exome sequencing reveals activating JAK1 and STAT3 mutations in breast implant-associated anaplastic large cell lymphoma anaplastic large cell lymphoma

Systemic anaplastic large cell lymphoma (sALCL) is an aggressive T-cell non Hodgkin lymphoma which is divided into two categories based on the expression of the anaplastic lymphoma kinase (ALK) protein (i.e. ALK-positive ALCL and ALK-negative ALCL). ALK-negative sALCL typically presents with

Circulating tumour DNA reflects treatment response and clonal evolution in chronic lymphocytic leukaemia

Several novel therapeutics are poised to change the natural history of chronic lymphocytic leukaemia (CLL) and the increasing use of these therapies has highlighted limitations of traditional disease monitoring methods. Here we demonstrate that circulating tumour DNA (ctDNA) is readily detectable in patients with CLL. Importantly, ctDNA does not simply mirror the genomic information contained within circulating malignant lymphocytes but instead parallels changes across different disease compartments following treatment with novel therapies. Serial ctDNA analysis allows clonal dynamics to be monitored over time and identifies the emergence of genomic changes associated with Richters syndrome (RS). In addition to conventional disease monitoring, ctDNA provides a unique opportunity for non-invasive serial analysis of CLL for molecular disease monitoring.

Molecular disease monitoring using circulating tumor DNA in myelodysplastic syndromes

The diagnosis and monitoring of myelodysplastic syndromes (MDSs) are highly reliant on bone marrow morphology, which is associated with substantial interobserver variability. Although azacitidine is the mainstay of treatment in MDS, only half of all patients respond. Therefore, there is an urgent need for improved modalities for the diagnosis and monitoring of MDSs. The majority of MDS patients have either clonal somatic karyotypic abnormalities and/or gene mutations that aid in the diagnosis and can be used to monitor treatment response. Circulating cell-free DNA is primarily derived from hematopoietic cells, and we surmised that the malignant MDS genome would be a major contributor to cell-free DNA levels in MDS patients as a result of ineffective hematopoiesis. Through analysis of serial bone marrow and matched plasma samples (n = 75), we demonstrate that cell-free circulating tumor DNA (ctDNA) is directly comparable to bone marrow biopsy in representing the genomic heterogeneity of malignant clones in MDS. Remarkably, we demonstrate that serial monitoring of ctDNA allows concurrent tracking of both mutations and karyotypic abnormalities throughout therapy and is able to anticipate treatment failure. These data highlight the role of ctDNA as a minimally invasive molecular disease monitoring strategy in MDS.

The molecular pathogenesis of B-cell non-Hodgkin lymphoma.

The B‐cell non‐Hodgkin lymphomas (B‐NHL) are a diverse group of haematological malignancies which arise from the mature B‐lymphocyte compartment. Recently, our understanding of the molecular pathogenesis of these disorders has greatly increased due to technological advances such as high‐throughput DNA sequencing techniques. A paradigm of B‐NHL pathogenesis has emerged where the normal genetic processes that are central to generating B‐cell receptor diversity (somatic hypermutation and class switch/VDJ recombination) also drive the genesis of large‐scale, chromosomal‐level genetic lesions and smaller‐scale gene‐level mutations to produce the malignant phenotypes observed. Whilst a significant degree of genetic heterogeneity exists within each B‐NHL subtype, the genetic lesions present within each subtype show a degree of convergence on common intracellular signalling, epigenetic and cell cycle pathways. This convergence gives an insight into the key oncogenic drivers of specific B‐NHL subtypes and potential targets for therapeutic intervention. This review covers the current understanding of the causative genetic processes of B‐NHL, the associated driving molecular lesions and the implications of these findings for the treatment of this group of disorders.

The Choice of Multiple Myeloma Induction Therapy Affects the Frequency and Severity of Oral Mucositis After Melphalan-Based Autologous Stem Cell Transplantation

INTRODUCTION/BACKGROUND Mucositis is a common complication of high-dose melphalan (HDM) used before autologous stem cell transplantation (ASCT) for multiple myeloma (MM). Mucositis rates are influenced by previous chemotherapy (CT) exposure. We examined the effect of induction therapy before ASCT on ASCT mucositis rates. PATIENTS AND METHODS Patients undergoing first 200 mg/m(2) HDM ASCT were assessed. Those receiving < 200 mg/m(2), or those with previous ASCT were excluded. Patients were evaluated depending on type of induction therapy (CT, immunomodulatory drug [IMiD], or proteasome inhibitor [PI]) before ASCT. A case record review was performed and data collected on response to induction, rates of Grade 3/4 mucositis, and days of total parenteral nutrition (TPN) or parenteral opiate analgesia. RESULTS One hundred twenty-eight patients with ASCT were assessed. Induction therapy was CT- (n = 62), IMiD- (n = 51), or PI-based (n = 15) therapy. Patient characteristics were overall similar, including median age, MM stage, and CD34(+) cell dose. IMiD-based therapy patients had lower rates of mucositis (33% vs. 53%; P = .03) and less opiate requirements (10% vs. 31%; P = .02) compared with those treated with CT. Rates of mucositis and opiate use in the PI group were not different to the CT cohorts (33% vs. 53%; P = .6 and 13% vs. 31%; P = .13), likely due to concurrent anthracycline exposure. TPN usage was similar (CT, 42%; IMiD, 35%; and PI, 20%), as was neutropenia duration and antibiotic usage. CONCLUSION Patients treated with IMiD-based regimens before HDM ASCT had significantly lower rates of mucositis than those treated with CT-based therapy. There were too few patients who received PI therapy to evaluate the effect.

Molecular lesions in B-cell lymphoproliferative disorders: recent contributions from studies utilizing high-throughput sequencing techniques

Abstract Next-generation sequencing techniques are powerful high-throughput methods that have enabled the comprehensive documentation of genetic lesions in numerous hematological malignancies. In recent times, the genomes of multiple different B-cell lymphoproliferative disorders including chronic lymphocytic leukemia, diffuse large B-cell lymphoma, Burkitt lymphoma, splenic marginal zone lymphoma, mantle cell lymphoma, hairy cell leukemia and Waldenström macroglobulinemia have been documented. Between them, these studies have reinforced and provided insight into the mechanisms for the dysregulation of known pathways (e.g. nuclear factor-κB [NF-κB]), uncovered the importance of new pathways for oncogenesis (e.g. mRNA processing), identified disease-defining mutations and provided meaningful new targets which are already being translated into therapeutic interventions. This review summarizes the molecular lesions that have been discovered in B-cell lymphoproliferative disorders thus far by studies utilizing high-throughput sequencing techniques and the aberrations in the numerous intracellular pathways that have been shown to be involved.

Plasmablastic Richter transformation as a resistance mechanism for chronic lymphocytic leukaemia treated with BCR signalling inhibitors

Auger, S., Duny, Y., Rossi, J.F. & Quittet, P. (2012) Rituximab before splenectomy in adults with primary idiopathic thrombocytopenic purpura: a meta-analysis. British Journal of Haematology, 158, 386–398. Barmparas, G., Lamb, A.W., Lee, D., Nguyen, B., Eng, J., Bloom, M.B. & Ley, E.J. (2015) Postoperative infection risk after splenectomy: a prospective cohort study. International Journal of Surgery, 17, 10–14. Chen, J., Ma, R., Yang, S., Lin, S., He, S. & Cai, X. (2014) Perioperative outcomes of laparoscopic versus open splenectomy for nontraumatic diseases: a meta-analysis. Chinese Medical Journal (English Language), 127, 2504–2510. Clavien, P.A., Barkun, J., de Oliveira, M.L., Vauthey, J.N., Dindo, D., Schulick, R.D., de Santiba~ nes, E., Pekolj, J., Slankamenac, K., Bassi, C., Graf, R., Vonlanthen, R., Padbury, R., Cameron, J.L. & Makuuchi, M. (2009) The Clavien-Dindo classification of surgical complications: five-year experience. Annals of Surgery, 250, 187–196. Davidson, R.N. & Wall, R.A. (2001) Prevention and management of infections in patients without a spleen. Clinical Microbiology and Infection, 7, 657–660. NICE (2013) Eltrombopag for treating chronic immune (idiopathic) thrombocytopenic purpura (review of technology appraisal 205): National Institute for Health and Care Excellence. Available at http://guidance.nice.org.uk/TA293 [Accessed March 13, 2016]. NICE (2014) Immune (idiopathic) thrombocytopenic purpura: rituximab: National Institute for Health and Care Excellence. Available at https://www.nice.org.uk/advice/esuom35/chapter/key-points-from-the-evidence [Accessed March 13, 2016]. Nyilas, A., Paszt, A., Simonka, Z., Abrah am, S., Borda, B., M an, E. & L az ar, G. (2015) Laparoscopic splenectomy is a safe method in cases of extremely large spleens. Journal of Laparoendoscopic Advanced Surgical Techniques, 25, 212–216. Patel, V. L., Mah evas, M., Lee, S. Y., Stasi, R., Cunningham-Rundles, S., Godeau, B., Kanter, J., Neufeld, E., Taube, T., Ramenghi, U., Shenoy, S., Ward, M. J., Mihatov, N., Patel, V. L., Bierling, P., Lesser, M., Cooper, N. & Bussel, J. B. (2012) Outcomes 5 years after response to rituximab therapy in children and adults with immune thrombocytopenia. Blood, 119, 5989–5995 Taniguchi, L.U., Correia, M.D. & Zampieri, F.G. (2014) Overwhelming post-splenectomy infection: narrative review of the literature. Surgical Infections, 15, 686–693.