Publications by authors named "David A Westerman"

39 Publications

BTK inhibitor therapy is effective in patients with CLL resistant to venetoclax.

Blood 2020 06;135(25):2266-2270

Department of Clinical Haematology, Royal Melbourne Hospital and Peter MacCallum Cancer Centre, Melbourne, VIC, Australia.

Highly active BTK inhibitors (BTKis) and the BCL2 inhibitor venetoclax have transformed the therapeutic landscape for chronic lymphocytic leukemia (CLL). Results of prospective clinical trials demonstrate the efficacy of venetoclax to salvage patients with disease progression on BTKis, but data on BTKi therapy after disease progression on venetoclax are limited, especially regarding durability of benefit. We retrospectively evaluated the records of 23 consecutive patients with relapsed/refractory CLL who received a BTKi (ibrutinib, n = 21; zanubrutinib, n = 2) after stopping venetoclax because of progressive disease. Median progression-free survival (PFS) and median overall survival after BTKi initiation were 34 months (range, <1 to 49) and 42 months (range, 2-49), respectively. Prior remission duration ≥24 months and attainment of complete remission or undetectable measurable residual disease on venetoclax were associated with longer PFS after BTKi salvage (P = .044 and P = .029, respectively). BTKi therapy achieved durable benefit for patients with the BCL2 Gly101Val venetoclax resistance mutation (estimated 24-month PFS, 69%). At a median survivor follow-up of 33 months (range, 2-53), 11 patients remained on BTKi and 12 had stopped therapy because of disease progression (n = 8) or toxicity (n = 4). Our findings indicate that BTKi therapy can provide durable CLL control after disease progression on venetoclax.
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http://dx.doi.org/10.1182/blood.2020004782DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7316215PMC
June 2020

Retinal ischemia due to extramedullary plasmacytomas of the orbit.

J Clin Neurosci 2020 Feb 22;72:447-449. Epub 2020 Jan 22.

Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Victoria, Australia; Clinical Haematology, Peter MacCallum Cancer Centre and Royal Melbourne Hospital, Melbourne, Victoria, Australia.

Visual disturbance is a common complaint in patients with multiple myeloma, both at diagnosis and later in their course, and has a broad differential. Here, we report a novel cause of visual disturbance, namely retinal ischemia due to extramedullary plasmacytomas of the orbit. A 69 year-old male patient with known multiple myeloma presented with reduced vision in his left eye. The patient had been initially diagnosed with IgG myeloma 9 months earlier and multiples lines of medical therapy had been unsuccessful. Ophthalmology review was organised and fundoscopic examination showed evidence of retinal ischemia. Computed tomography of the orbits demonstrated multiple enhancing masses within both orbits, consistent with extramedullary plasmacytomas. The presence of retinal ischemia was thus attributed to mass effect on the orbital vessels. Extramedullary plasmacytomas within the orbit are a rare manifestation of multiple myeloma, but important to consider as a possible cause of visual disturbance.
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http://dx.doi.org/10.1016/j.jocn.2020.01.052DOI Listing
February 2020

Undetectable peripheral blood MRD should be the goal of venetoclax in CLL, but attainment plateaus after 24 months.

Blood Adv 2020 01;4(1):165-173

Department of Clinical Haematology, The Royal Melbourne Hospital and Peter MacCallum Cancer Centre, Parkville, Australia.

The highly selective BCL2 inhibitor venetoclax achieves deep responses in patients with relapsed or refractory (R/R) chronic lymphocytic leukemia (CLL), including undetectable minimal residual disease (uMRD). We retrospectively reviewed 62 patients with CLL treated with venetoclax to investigate the performance of peripheral blood (PB) compared with bone marrow (BM) assessment of MRD; the kinetics, clinicopathological associations, and longer-term outcomes of uMRD attainment and recrudescence; and the ability of venetoclax dose escalation to deepen responses. Among 16 patients who achieved PB uMRD and had contemporaneous BM assessments, 13 (81%) had confirmed BM uMRD, and patients with PB uMRD had outcomes at least as favorable as those with BM uMRD for time to progression, overall survival, and MRD recrudescence. Excluding 2 patients lacking earlier assessment, the median time to PB uMRD was 18 (range, 5-26) months, with 90% of instances achieved by 24 months. There was no new PB uMRD attainment after 24 months without treatment intensification. The dominant association with earlier attainment of uMRD was concurrent rituximab (P = .012). Complex karyotype was associated with inferior uMRD attainment after 12 months of therapy (P = .015), and patients attaining uMRD whose disease harbored TP53 abnormalities demonstrated a trend toward earlier recrudescence (P = .089). Of patients who received venetoclax dose escalations, 4 (27%) of 15 achieved improvements in response. For patients with R/R CLL receiving venetoclax, PB uMRD commonly correlates with BM uMRD and is associated with a comparable longer-term prognosis. Concurrent rituximab augments uMRD attainment, but dose escalation and further treatment beyond 24 months infrequently deepen responses.
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http://dx.doi.org/10.1182/bloodadvances.2019000864DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6960473PMC
January 2020

Characterization of a novel venetoclax resistance mutation (BCL2 Phe104Ile) observed in follicular lymphoma.

Br J Haematol 2019 09 24;186(6):e188-e191. Epub 2019 Jun 24.

Clinical Haematology, Peter MacCallum Cancer Centre and Royal Melbourne Hospital, Melbourne, Australia.

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http://dx.doi.org/10.1111/bjh.16069DOI Listing
September 2019

Acquisition of the Recurrent Gly101Val Mutation in BCL2 Confers Resistance to Venetoclax in Patients with Progressive Chronic Lymphocytic Leukemia.

Cancer Discov 2019 03 4;9(3):342-353. Epub 2018 Dec 4.

Clinical Haematology, Peter MacCallum Cancer Centre and Royal Melbourne Hospital, Melbourne, Victoria, Australia.

The BCL2 inhibitor venetoclax induces high rates of durable remission in patients with previously treated chronic lymphocytic leukemia (CLL). However, despite continuous daily treatment, leukemia recurs in most patients. To investigate the mechanisms of secondary resistance, we analyzed paired pre-venetoclax and progression samples from 15 patients with CLL progression enrolled on venetoclax clinical trials. The novel Gly101Val mutation in BCL2 was identified at progression in 7 patients, but not at study entry. It was first detectable after 19 to 42 months of therapy, and its emergence anticipated clinical disease progression by many months. Gly101Val reduces the affinity of BCL2 for venetoclax by ∼180-fold in surface plasmon resonance assays, thereby preventing the drug from displacing proapoptotic mediators from BCL2 in cells and conferring acquired resistance in cell lines and primary patient cells. This mutation provides new insights into the pathobiology of venetoclax resistance and provides a potential biomarker of impending clinical relapse. SIGNIFICANCE: Why CLL recurs in patients who achieve remission with the BCL2 inhibitor venetoclax has been unknown. We provide the first description of an acquired point mutation in BCL2 arising recurrently and exclusively in venetoclax-treated patients. The mutation reduces venetoclax binding and is sufficient to confer resistance...
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http://dx.doi.org/10.1158/2159-8290.CD-18-1119DOI Listing
March 2019

Clinicopathological differences exist between CALR- and JAK2-mutated myeloproliferative neoplasms despite a similar molecular landscape: data from targeted next-generation sequencing in the diagnostic laboratory.

Ann Hematol 2017 May 4;96(5):725-732. Epub 2017 Feb 4.

Division of Cancer Medicine, Department of Pathology, Peter MacCallum Cancer Centre, East Melbourne, Melbourne, Australia.

Mutations in CALR have recently been detected in JAK2-negative myeloproliferative neoplasms (MPNs) and are key pathological drivers in these diseases. CALR-mutated MPNs are shown to have numerous clinicopathological differences to JAK2-mutated MPNs. The basis of these differences is poorly understood. It is unknown whether these differences result directly from any differences in intracellular signalling abnormalities induced by JAK2/CALR mutations or whether they relate to other phenomena such as a differing spectrum of genetic lesions between the two groups. We aimed to review the clinicopathological and molecular features of CALR- and JAK2-mutated MPNs from samples referred for diagnostic testing using a custom-designed targeted next-generation sequencing (NGS) panel. Eighty-nine CALR-mutated cases were compared with 70 JAK2-mutated cases. CALR-mutated MPNs showed higher platelet counts and a female predominance as compared to JAK2-mutated MPNs in our cohort. We have also observed differences between CALR mutation subtypes in terms of disease phenotype, mutational frequency and allelic burden. Type 1 CALR mutations were found to be more common in myelofibrosis, associated with a higher frequency and number of additional mutations and a higher mutant allelic burden as compared to type 2 CALR mutations. Despite these biological differences, our molecular characterisation suggests that CALR- and JAK2-mutated MPNs are broadly similar in terms of the quantity, frequency and spectrum of co-occurring mutations and therefore observed biological differences are likely to not be heavily influenced by the nature and quantity of co-mutated genes.
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http://dx.doi.org/10.1007/s00277-017-2937-6DOI Listing
May 2017

T-cell acute leukaemia exhibits dynamic interactions with bone marrow microenvironments.

Nature 2016 10 17;538(7626):518-522. Epub 2016 Oct 17.

Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, London SW7 2AZ, UK.

It is widely accepted that complex interactions between cancer cells and their surrounding microenvironment contribute to disease development, chemo-resistance and disease relapse. In light of this observed interdependency, novel therapeutic interventions that target specific cancer stroma cell lineages and their interactions are being sought. Here we studied a mouse model of human T-cell acute lymphoblastic leukaemia (T-ALL) and used intravital microscopy to monitor the progression of disease within the bone marrow at both the tissue-wide and single-cell level over time, from bone marrow seeding to development/selection of chemo-resistance. We observed highly dynamic cellular interactions and promiscuous distribution of leukaemia cells that migrated across the bone marrow, without showing any preferential association with bone marrow sub-compartments. Unexpectedly, this behaviour was maintained throughout disease development, from the earliest bone marrow seeding to response and resistance to chemotherapy. Our results reveal that T-ALL cells do not depend on specific bone marrow microenvironments for propagation of disease, nor for the selection of chemo-resistant clones, suggesting that a stochastic mechanism underlies these processes. Yet, although T-ALL infiltration and progression are independent of the stroma, accumulated disease burden leads to rapid, selective remodelling of the endosteal space, resulting in a complete loss of mature osteoblastic cells while perivascular cells are maintained. This outcome leads to a shift in the balance of endogenous bone marrow stroma, towards a composition associated with less efficient haematopoietic stem cell function. This novel, dynamic analysis of T-ALL interactions with the bone marrow microenvironment in vivo, supported by evidence from human T-ALL samples, highlights that future therapeutic interventions should target the migration and promiscuous interactions of cancer cells with the surrounding microenvironment, rather than specific bone marrow stroma, to combat the invasion by and survival of chemo-resistant T-ALL cells.
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http://dx.doi.org/10.1038/nature19801DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5164929PMC
October 2016

Risk of thromboembolism with lymphoma: myth or reality?

Leuk Lymphoma 2016 12 5;57(12):2736-2738. Epub 2016 Jul 5.

a Division of Cancer Medicine , Peter MacCallum Cancer Centre , East Melbourne , Melbourne , Australia.

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http://dx.doi.org/10.1080/10428194.2016.1204658DOI Listing
December 2016

Role of immunohistochemistry in the era of genetic testing in MYC-positive aggressive B-cell lymphomas: a study of 209 cases.

J Clin Pathol 2016 Mar 25;69(3):266-70. Epub 2015 Aug 25.

Division of Cancer Medicine, Department of Pathology, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia University of Melbourne, Department of Pathology, Parkville, Victoria, Australia.

Aims: MYC rearrangements with or without BCL2 rearrangements have been shown to be associated with poor prognosis and inferior survival in diffuse large B-cell lymphomas (DLBCL). Most of these cases are still diagnosed by fluorescent in situ hybridisation (FISH) testing, which is expensive, requires expertise and is not routinely available in all laboratories. Immunohistochemistry (IHC) is widely available and has the potential to be used as a screening test to identify cases with increased protein expression and select cases that require confirmatory testing. We correlated the expression of MYC and BCL2 by IHC with FISH studies in an attempt to define a cut-off value, which can be used by laboratories to select cases requiring confirmatory FISH testing. The prevalence of MYC-positive DLBCL and double-hit lymphoma (DHL) has also been studied.

Methods: 209 cases comprising of 15 cases of Burkitt lymphoma (BL), 13 cases of intermediate BL/DLBCL and 181 cases of DLBCL were included. IHC and FISH for MYC and BCL2 were performed and the results were correlated.

Results: The prevalence of MYC-positive DLBCL and MYC/BCL2DHL was 13.4% and 7.4%, respectively, in our study. Germinal-centre subtype was more common in MYC-positive DLBCL and DHL. MYC-positive DLBCL also showed higher median Ki-67 (>90%) and CD10 positivity as compared with MYC-negative cases.

Conclusions: IHC can be used for screening cases, which require further confirmatory FISH testing. We recommend a cut-off value of ≥30% for MYC by IHC; however, international standardisation of these values is necessary to provide uniformity among laboratories.
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http://dx.doi.org/10.1136/jclinpath-2015-203002DOI Listing
March 2016

Prevention of thromboembolism in myeloma: expanding the tool-box of assays to predict the risk?

Leuk Lymphoma 2015 7;56(12):3246-7. Epub 2015 Jul 7.

a Division of Cancer Medicine, Peter MacCallum Cancer Centre , East Melbourne, Melbourne , Australia.

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http://dx.doi.org/10.3109/10428194.2015.1055487DOI Listing
August 2016

Lack of durable disease control with chemotherapy for mycosis fungoides and Sézary syndrome: a comparative study of systemic therapy.

Blood 2015 Jan 21;125(1):71-81. Epub 2014 Oct 21.

Division of Haematology and Cancer Medicine, Peter MacCallum Cancer Centre, Melbourne, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Australia;

Numerous systemic treatment options exist for patients with mycosis fungoides (MF) and Sézary syndrome (SS), but no large comparative studies are published. To study the efficacy of treatments, a retrospective analysis of our cutaneous lymphoma database was undertaken, with 198 MF/SS patients undergoing systemic therapies. The primary end point was time to next treatment (TTNT). Patients with advanced-stage disease made up 53%. The median follow-up time from diagnosis for all alive patients was 4.9 years (range 0.3-39.6), with a median survival of 11.4 years. Patients received a median of 3 lines of therapy (range 1-13), resulting in 709 treatment episodes. Twenty-eight treatment modalities were analyzed. The median TTNT for single- or multiagent chemotherapy was only 3.9 months (95% confidence interval [CI] 3.2-5.1), with few durable remissions. α-interferon gave a median TTNT of 8.7 months (95% CI 6.0-18.0), and histone deacetylase inhibitors (HDACi) gave a median TTNT of 4.5 months (95% CI 4.0-6.1). When compared directly with chemotherapy, interferon and HDACi both had greater TTNT (P < .00001 and P = .01, respectively). This study confirms that all chemotherapy regimens assessed have very modest efficacy; we recommend their use be restricted until other options are exhausted.
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http://dx.doi.org/10.1182/blood-2014-07-588236DOI Listing
January 2015

KIT D816V mutation detection: a comparative study using peripheral blood, bone marrow aspirate and bone marrow trephine samples for detection of KIT mutations in patients with systemic mastocytosis.

Leuk Lymphoma 2014 Sep 28;55(9):2202-3. Epub 2014 Jan 28.

Division of Cancer Medicine, Department of Pathology, Peter MacCallum Cancer Centre , Melbourne , Australia.

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http://dx.doi.org/10.3109/10428194.2013.876498DOI Listing
September 2014

Cerebrospinal fluid analysis by flow cytometry in acute lymphoblastic leukemia: is it all that it is cracked up to be?

Leuk Lymphoma 2014 Jul 24;55(7):1441-3. Epub 2014 Feb 24.

Department of Pathology, Peter MacCallum Cancer Centre , East Melbourne, Victoria , Australia.

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http://dx.doi.org/10.3109/10428194.2013.876499DOI Listing
July 2014

Persistence and efficacy of second generation CAR T cell against the LeY antigen in acute myeloid leukemia.

Mol Ther 2013 Nov 8;21(11):2122-9. Epub 2013 Jul 8.

1] Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia [2] Hematology Immunology Translational Research Laboratory, Peter MacCallum Cancer Centre, East Melbourne, Australia [3] Cancer Immunology Research Program, Peter MacCallum Cancer Centre, East Melbourne, Australia [4] Division of Cancer Medicine, Peter MacCallum Cancer Centre, East Melbourne, Australia [5] Centre for Blood Cell Therapies, Peter MacCallum Cancer Centre, East Melbourne, Australia.

In a phase I study of autologous chimeric antigen receptor (CAR) anti-LeY T-cell therapy of acute myeloid leukemia (AML), we examined the safety and postinfusion persistence of adoptively transferred T cells. Following fludarabine-containing preconditioning, four patients received up to 1.3 × 109 total T cells, of which 14-38% expressed the CAR. Grade 3 or 4 toxicity was not observed. One patient achieved a cytogenetic remission whereas another with active leukemia had a reduction in peripheral blood (PB) blasts and a third showed a protracted remission. Using an aliquot of In111-labeled CAR T cells, we demonstrated trafficking to the bone marrow (BM) in those patients with the greatest clinical benefit. Furthermore, in a patient with leukemia cutis, CAR T cells infiltrated proven sites of disease. Serial PCR of PB and BM for the LeY transgene demonstrated that infused CAR T cells persisted for up to 10 months. Our study supports the feasibility and safety of CAR-T-cell therapy in high-risk AML, and demonstrates durable in vivo persistence.
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http://dx.doi.org/10.1038/mt.2013.154DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3831035PMC
November 2013

Role of flow cytometry in myelodysplastic syndromes: diagnosis, classification, prognosis and response assessment.

Leuk Lymphoma 2014 Apr 20;55(4):749-60. Epub 2013 Aug 20.

Division of Cancer Medicine, Peter MacCallum Cancer Centre , East Melbourne, Melbourne , Australia.

Myelodysplastic syndromes (MDS) are a heterogeneous group of myeloid neoplasms. With the emergence of therapeutic options, attempts to standardize diagnostic, prognostic and response criteria to guide treatment decisions are increasingly important. This has been achieved in part by the revised 2008 World Health Organization classification and consensus guidelines outlining refined definitions and standards. Conventional criteria have limitations in terms of sensitivity and specificity. Multiparameter flow cytometry (FC) can be used real-time, and is a highly reproducible and objective way of assessing the pattern of expression of multiple antigens on a single hematopoietic cell and defined subpopulations. By comparing antigen expression within maturing myelomonocytic populations with that identified on the equivalent normal cells, abnormalities identified may provide a diagnostic indication of stem cell dysmaturation. There are now increasingly robust data demonstrating the capacity of FC to discriminate MDS from non-clonal cytopenias and dysplasia, as well as further refine disease classification and prognostication, which will be reviewed here.
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http://dx.doi.org/10.3109/10428194.2013.820291DOI Listing
April 2014

A no-prophylaxis platelet-transfusion strategy for hematologic cancers.

N Engl J Med 2013 May;368(19):1771-80

National Health Service (NHS) Blood and Transplant, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, and Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom.

Background: The effectiveness of platelet transfusions to prevent bleeding in patients with hematologic cancers remains unclear. This trial assessed whether a policy of not giving prophylactic platelet transfusions was as effective and safe as a policy of providing prophylaxis.

Methods: We conducted this randomized, open-label, noninferiority trial at 14 centers in the United Kingdom and Australia. Patients were randomly assigned to receive, or not to receive, prophylactic platelet transfusions when morning platelet counts were less than 10×10(9) per liter. Eligible patients were persons 16 years of age or older who were receiving chemotherapy or undergoing stem-cell transplantation and who had or were expected to have thrombocytopenia. The primary end point was bleeding of World Health Organization (WHO) grade 2, 3, or 4 up to 30 days after randomization.

Results: A total of 600 patients (301 in the no-prophylaxis group and 299 in the prophylaxis group) underwent randomization between 2006 and 2011. Bleeding of WHO grade 2, 3, or 4 occurred in 151 of 300 patients (50%) in the no-prophylaxis group, as compared with 128 of 298 (43%) in the prophylaxis group (adjusted difference in proportions, 8.4 percentage points; 90% confidence interval, 1.7 to 15.2; P=0.06 for noninferiority). Patients in the no-prophylaxis group had more days with bleeding and a shorter time to the first bleeding episode than did patients in the prophylaxis group. Platelet use was markedly reduced in the no-prophylaxis group. A prespecified subgroup analysis identified similar rates of bleeding in the two study groups among patients undergoing autologous stem-cell transplantation.

Conclusions: The results of our study support the need for the continued use of prophylaxis with platelet transfusion and show the benefit of such prophylaxis for reducing bleeding, as compared with no prophylaxis. A significant number of patients had bleeding despite prophylaxis. (Funded by the National Health Service Blood and Transplant Research and Development Committee and the Australian Red Cross Blood Service; TOPPS Controlled-Trials.com number, ISRCTN08758735.).
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http://dx.doi.org/10.1056/NEJMoa1212772DOI Listing
May 2013

Quantitative threefold allele-specific PCR (QuanTAS-PCR) for highly sensitive JAK2 V617F mutant allele detection.

BMC Cancer 2013 Apr 24;13:206. Epub 2013 Apr 24.

Department of Pathology, Peter MacCallum Cancer Centre, St Andrews Place, East Melbourne, Victoria 3002, Australia.

Background: The JAK2 V617F mutation is the most frequent somatic change in myeloproliferative neoplasms, making it an important tumour-specific marker for diagnostic purposes and for the detection of minimal residual disease. Sensitive quantitative assays are required for both applications, particularly for the monitoring of minimal residual disease, which requires not only high sensitivity but also very high specificity.

Methods: We developed a highly sensitive probe-free quantitative mutant-allele detection method, Quantitative Threefold Allele-Specific PCR (QuanTAS-PCR), that is performed in a closed-tube system, thus eliminating the manipulation of PCR products. QuantTAS-PCR uses a threefold approach to ensure allele-specific amplification of the mutant sequence: (i) a mutant allele-specific primer, (ii) a 3'dideoxy blocker to suppress false-positive amplification from the wild-type template and (iii) a PCR specificity enhancer, also to suppress false-positive amplification from the wild-type template. Mutant alleles were quantified relative to exon 9 of JAK2.

Results: We showed that the addition of the 3'dideoxy blocker suppressed but did not eliminate false-positive amplification from the wild-type template. However, the addition of the PCR specificity enhancer near eliminated false-positive amplification from the wild-type allele. Further discrimination between true and false positives was enabled by using the quantification cycle (Cq) value of a single mutant template as a cut-off point, thus enabling robust distinction between true and false positives. As 10,000 JAK2 templates were used per replicate, the assay had a sensitivity of 1/10(-4) per replicate. Greater sensitivity could be reached by increasing the number of replicates analysed. Variation in replicates when low mutant-allele templates were present necessitated the use of a statistics-based approach to estimate the load of mutant JAK2 copies. QuanTAS-PCR showed comparable quantitative results when validated against a commercial assay.

Conclusions: QuanTAS-PCR is a simple, cost-efficient, closed-tube method for JAK2 V617F mutation quantification that can detect very low levels of the mutant allele, thus enabling analysis of minimal residual disease. The approach can be extended to the detection of other recurrent single nucleotide somatic changes in cancer.
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http://dx.doi.org/10.1186/1471-2407-13-206DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3658971PMC
April 2013

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

Leuk Lymphoma 2014 Jan 9;55(1):19-30. Epub 2013 May 9.

Peter MacCallum Cancer Centre, Division of Cancer Medicine , East Melbourne, Victoria , Australia.

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.
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http://dx.doi.org/10.3109/10428194.2013.792112DOI Listing
January 2014

Under-recognition of platelet dysfunction in myelodysplastic syndromes: are we only seeing the tip of the iceberg?

Leuk Lymphoma 2013 Jan 10;54(1):11-3. Epub 2012 Sep 10.

Division of Cancer Medicine, Peter MacCallum Cancer Centre, East Melbourne, Melbourne, Australia.

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http://dx.doi.org/10.3109/10428194.2012.710908DOI Listing
January 2013

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

Haematologica 2012 May 1;97(5):780-3. Epub 2011 Dec 1.

Peter MacCallum Cancer Centre, Division of Cancer Medicine, East Melbourne, Victoria, Australia.

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.
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http://dx.doi.org/10.3324/haematol.2011.054874DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3342983PMC
May 2012

Short-term warfarin reversal for elective surgery--using low-dose intravenous vitamin K: safe, reliable and convenient*.

Br J Haematol 2011 Sep 14;154(5):626-34. Epub 2011 Jul 14.

Division of Cancer Medicine Centre for Biostatistics & Clinical Trials, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia.

Peri-procedural management of warfarin reflects an intricate balance between the restoration of haemostasis and appropriate thromboprophylaxis. This prospective single-arm study assessed the safety and efficacy of a convenient schedule, incorporating low-dose intravenous vitamin K (vitK(IV) ) for short-term warfarin reversal prior to elective surgery, as well as vitK-dependent factor levels (vitK-Factors) and International Normalized Ratio (INR) pre- and post-vitK(IV) . One seventy eight patients on long-term warfarin received 3mg vitK(IV) 12-18 h pre-procedure with no adverse reactions. 167/178 (94%) achieved an INR≤1·5 post-vitK(IV) on the day of surgery, while all achieved INR≤1·7. Four patients had procedure-associated major bleeding, but importantly had achieved a pre-procedure INR<1·5 and vitK-Factors >0·30iu/ml. No patient suffered a symptomatic thromboembolism during the 6-week follow-up. Median days to re-establish a therapeutic INR were 4 (range 2-11). VitK(IV) near normalized all vitK-Factors, with a uniform pattern of depletion and repletion in association with an increase and decrease in INR, respectively; and from the data, INR<1·5 correlated with vitK-Factors >0·30iu/ml. Low-dose vitK(IV) for short-term warfarin reversal was reliable and safe, and successfully lowered the INR to an acceptable level for planned surgery, with no excess of bleeding, thromboembolism, delayed discharge, or resistance to warfarin. The protocol was simple and convenient for both the patients and the healthcare institution.
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http://dx.doi.org/10.1111/j.1365-2141.2011.08787.xDOI Listing
September 2011

Prophylactic intravenous immunoglobulin during autologous haemopoietic stem cell transplantation for multiple myeloma is not associated with reduced infectious complications.

Ann Hematol 2011 Oct 15;90(10):1167-72. Epub 2011 Jun 15.

Division of Cancer Medicine, Peter MacCallum Cancer Centre, East Melbourne, Melbourne, Victoria, Australia.

Patients with multiple myeloma undergoing autologous haemopoietic stem cell transplantation (ASCT) are at high risk for infectious complications. Peri-transplant intravenous immunoglobulin (IVIG) has been used with the aim of reducing these risks. Our retrospective, non-randomised study of peri-transplant IVIG use and effect on infectious complications in 266 ASCTs for myeloma from 2000 to 2009 at a major metropolitan referral centre for haematological malignancies found no difference between those receiving peri-transplant IVIG (0.4 g/kg) (n=130) and those who were not (n=110) with regard to bloodstream infections, pneumonia, urinary tract or gastrointestinal infections. When analysed according to pre-transplant therapy (conventional chemotherapy versus novel agents), there was no significant difference in infectious complications between those who did or did not receive peri-transplant IVIG. In conclusion, our study did not show a benefit for the use of peri-transplant IVIG (0.4 g/kg) to reduce infectious complications in a large cohort of patients with myeloma undergoing ASCT. In the absence of data supporting efficacy in this context, there appears to be no benefit in the routine use of IVIG for this purpose.
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http://dx.doi.org/10.1007/s00277-011-1275-3DOI Listing
October 2011

Bone-marrow plasma cell burden correlates with IgM paraprotein concentration in Waldenstrom macroglobulinaemia.

J Clin Pathol 2011 Jun 6;64(6):520-3. Epub 2011 Apr 6.

Department of Diagnostic Haematology, The Royal Melbourne Hospital, Parkville, Victoria, Australia.

Aims: Correlations between the marrow histopathology and clinical findings in Waldenström macroglobulinaemia (WM) are not well defined, and the pathophysiology of the plasma cell involvement is poorly understood. The authors used a standardised immunohistological approach to the enumeration of B lymphocyte and plasma cell compartments in the bone-marrow trephine to investigate associations between bone-marrow morphology and clinical/laboratory indices.

Methods: In 80 newly diagnosed, untreated cases of WM, the authors determined the degree and pattern of B lymphocyte (CD20+) and plasma cell (CD138+) infiltration in the bone-marrow trephine, as defined by immunohistochemistry, and correlated the disease in the marrow with components of the international scoring system for WM (age, serum IgM paraprotein level, haemoglobin, platelet count and β(2) microglobulin). Plasma cell clonality was assessed by κ and λ staining.

Results: Serum IgM paraprotein concentration was related to the plasma cell burden in the bone marrow (coefficient 0.231, p<0.005), but not the B lymphocytic infiltrate. Overall lymphoplasmacytic disease burden weakly correlated with severity of anaemia (coefficient 0.236, p=0.055). In 28/28 evaluated cases, plasma cells exhibited light chain restriction that was concordant with both that of the B lymphocytic infiltrate and paraprotein.

Conclusions: Bone-marrow features, in particular the degree of plasma cell infiltration, correlate with IgM paraprotein concentration at diagnosis in WM. The plasma cell compartment in this condition appears to be part of the neoplastic clone. In WM, specific evaluation of the plasma cell compartment in the bone marrow at baseline and following therapy may be valuable.
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http://dx.doi.org/10.1136/jcp.2010.088591DOI Listing
June 2011

Detection of NPM1 exon 12 mutations and FLT3 - internal tandem duplications by high resolution melting analysis in normal karyotype acute myeloid leukemia.

J Hematol Oncol 2008 Jul 29;1:10. Epub 2008 Jul 29.

Department of Pathology, Peter MacCallum Cancer Centre, Melbourne, Australia.

Background: Molecular characterisation of normal karyotype acute myeloid leukemia (NK-AML) allows prognostic stratification and potentially can alter treatment choices and pathways. Approximately 45-60% of patients with NK-AML carry NPM1 gene mutations and are associated with a favourable clinical outcome when FLT3-internal tandem duplications (ITD) are absent. High resolution melting (HRM) is a novel screening method that enables rapid identification of mutation positive DNA samples.

Results: We developed HRM assays to detect NPM1 mutations and FLT3-ITD and tested diagnostic samples from 44 NK-AML patients. Eight were NPM1 mutation positive only, 4 were both NPM1 mutation and FLT3-ITD positive and 4 were FLT3-ITD positive only. A novel point mutation Y572C (c.1715A>G) in exon 14 of FLT3 was also detected. In the group with de novo NK-AML, 40% (12/29) were NPM1 mutation positive whereas NPM1 mutations were observed in 20% (3/15) of secondary NK-AML cases. Sequencing was performed and demonstrated 100% concordance with the HRM results.

Conclusion: HRM is a rapid and efficient method of screening NK-AML samples for both novel and known NPM1 and FLT3 mutations. NPM1 mutations can be observed in both primary and secondary NK-AML cases.
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http://dx.doi.org/10.1186/1756-8722-1-10DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2517593PMC
July 2008
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