- Email: [email protected]
Molecular aspects of AML
S38
Pathology (2017), 49(S1)
PATHOLOGY 2017 ABSTRACT SUPPLEMENT
myeloid clone after induction therapy and was reclassified as mixed phenotypic acute leukaemia, B/myeloid, NOS, with cytogenetic and molecular results that have been reported in both myeloid and lymphoid malignancies. His case highlights the rare circumstance of the difficulty forming an accurate diagnosis despite extensive investigations and the impact this has on treatment outcomes. AN AMAZING RECOVERY Monique Menzies Wojtowicz Department of Haematology, Prince of Wales Hospital, Sydney, NSW, Australia Mr HV is a 23-year-old man with a history of T-acute lymphoblastic leukaemia, who defied poor prognosis disease and treatment-related complications to achieve remission. He presented with a mediastinal mass and constitutional symptoms. The diagnosis was made with circulating blasts in the peripheral blood and 96% blasts in the bone marrow with an immunophenotype consistent with T-ALL. The karyotype demonstrated a t(4;11) and deletion 5q. FISH was negative for BCR-ABL1 and KMT2A. Translocation (4;11) is an uncommon finding in ALL; it has been estimated to occur in 2–5% of adult T-ALL and confers a poor prognosis. Mr HV participated in the ALLG ALL-6 study in 2014 which involves treatment with a paediatric-style regimen using minimum residual disease (MRD) monitoring. MRD was monitored with cytogenetics, real-time quantitative PCR and flow cytometry. Treatment complications included seizures and paralysis due to Peg-asparaginase-related bilateral cortical vein thrombosis. An additional complication was bilateral retinal infarcts with blindness due to thrombocytopenia. Despite these complications, Mr HV achieved remission and due to his high risk status underwent a successful matched unrelated donor transplant in first complete remission. Transplant complications included GVHD of the liver, eyes and mouth and CMV viraemia. He is currently over a year post transplant. FISHING FOR ANSWERS: NUP214-ABL1 IN TLYMPHOBLASTIC LEUKAEMIA/LYMPHOMA Fiona Swain1, David Fairbairn1, Mark McKinley1, Bronwyn Williams1, Andrew Moore2, Louise Seymour1 1 Pathology Queensland, Royal Brisbane and Women’s Hospital, and 2Lady Cilento Children’s Hospital, Brisbane, Qld, Australia NUP214-ABL1 translocation is found in 6% of T-cell lymphoblastic leukaemia/lymphoma and has also been reported in B-cell lymphoblastic leukaemia/lymphoma. The NUP214-ABL1 fusion protein is a constitutively active tyrosine kinase protein akin to the BCR-ABL1 fusion protein; however, unlike BCRABL1, this translocation is often a late event and amplification of the fusion transcript is necessary for oncogenicity. Furthermore, other additional classes of kinases have been identified as prerequisites for NUP214-ABL mediated neoplastic transformation. ABL1 and NUP214 are both located on chromosome 9 at 9q34; thus this is a cryptic translocation that cannot be detected on conventional karyotyping. It is not currently part of a standard
FISH work-up in T-cell lymphoblastic leukaemia/lymphoma; however, its presence may be suggested by detection of multiple copies of ABL1 due to episomal amplification of the fusion gene (using a BCR-ABL1 dual fusion probe set). The NUP214-ABL1 translocation can be confirmed by PCR. The significance of NUP214-ABL1 translocation is three-fold: molecular studies can be used for minimal residual disease (MRD) analysis; it may ultimately provide prognostic significance; and there is a potential role for tyrosine kinase inhibitors, in conjunction with standard chemotherapy. MOLECULAR ASPECTS OF AML William Stevenson Department of Haematology and Transfusion Medicine, Royal North Shore Hospital, Sydney, NSW, Australia Acute myeloid leukaemia (AML) is characterised by a clonal expansion of myeloid cells in the bone marrow with subsequent development of bone marrow failure. Current laboratory investigation for diagnostic AML samples in Australasia would typically include assessment of morphology, flow cytometry and cytogenetic analysis with consideration for targeted genetic testing of PML-RARA, CBF translocations, FLT3, NPM1 and CEBPA. This limited approach to genetic testing is likely to expand in coming years with increased knowledge of the AML genome. Driver mutations can now be identified in most AML samples with the interaction of multiple mutations in the same sample considered important for prognostication. The WHO classification of AML has increasingly relied on identification of these genetic lesions with the 2016 revision suggesting an increased number of diagnostic entities associated with recurrent genetic abnormalities as well as recognition that some of these identified mutations may represent underlying germ line changes that predispose to myeloid malignancy. The rapid improvement in sequencing technologies have allowed increasing genetic data to be obtained from cancer samples such that candidate gene panels are likely to offer improvements in leukaemia management with better disease prognostication, identification of targetable mutations for drug therapy and improved minimal residual disease detection. MINIMAL RESIDUAL DISEASE ASSESSMENT BY FLOW CYTOMETRY IN ACUTE LYMPHOBLASTIC LEUKAEMIA Janine Campbell Royal Children’s Hospital, Melbourne, Vic, Australia Minimal residual disease (MRD) assessment during the early stages of therapy for acute lymphoblastic leukaemia (ALL) is an important marker of prognosis. Contemporary paediatric protocols use MRD results for risk stratification, therapy assignment and post HSCT monitoring. Increasingly, MRD assessment is also being incorporated into treatment algorithms in adult ALL. As a result, diagnostic laboratories are being asked to introduce MRD analysis by flow cytometry. This presentation will cover various aspects of the MRD assay, including the establishment of lymphoid maturation templates using normal controls, quality control, and therapyinduced changes in leukaemia immunophenotypes. Common
Pathology (2017), 49(S1)
PATHOLOGY 2017 ABSTRACT SUPPLEMENT
myeloid clone after induction therapy and was reclassified as mixed phenotypic acute leukaemia, B/myeloid, NOS, with cytogenetic and molecular results that have been reported in both myeloid and lymphoid malignancies. His case highlights the rare circumstance of the difficulty forming an accurate diagnosis despite extensive investigations and the impact this has on treatment outcomes. AN AMAZING RECOVERY Monique Menzies Wojtowicz Department of Haematology, Prince of Wales Hospital, Sydney, NSW, Australia Mr HV is a 23-year-old man with a history of T-acute lymphoblastic leukaemia, who defied poor prognosis disease and treatment-related complications to achieve remission. He presented with a mediastinal mass and constitutional symptoms. The diagnosis was made with circulating blasts in the peripheral blood and 96% blasts in the bone marrow with an immunophenotype consistent with T-ALL. The karyotype demonstrated a t(4;11) and deletion 5q. FISH was negative for BCR-ABL1 and KMT2A. Translocation (4;11) is an uncommon finding in ALL; it has been estimated to occur in 2–5% of adult T-ALL and confers a poor prognosis. Mr HV participated in the ALLG ALL-6 study in 2014 which involves treatment with a paediatric-style regimen using minimum residual disease (MRD) monitoring. MRD was monitored with cytogenetics, real-time quantitative PCR and flow cytometry. Treatment complications included seizures and paralysis due to Peg-asparaginase-related bilateral cortical vein thrombosis. An additional complication was bilateral retinal infarcts with blindness due to thrombocytopenia. Despite these complications, Mr HV achieved remission and due to his high risk status underwent a successful matched unrelated donor transplant in first complete remission. Transplant complications included GVHD of the liver, eyes and mouth and CMV viraemia. He is currently over a year post transplant. FISHING FOR ANSWERS: NUP214-ABL1 IN TLYMPHOBLASTIC LEUKAEMIA/LYMPHOMA Fiona Swain1, David Fairbairn1, Mark McKinley1, Bronwyn Williams1, Andrew Moore2, Louise Seymour1 1 Pathology Queensland, Royal Brisbane and Women’s Hospital, and 2Lady Cilento Children’s Hospital, Brisbane, Qld, Australia NUP214-ABL1 translocation is found in 6% of T-cell lymphoblastic leukaemia/lymphoma and has also been reported in B-cell lymphoblastic leukaemia/lymphoma. The NUP214-ABL1 fusion protein is a constitutively active tyrosine kinase protein akin to the BCR-ABL1 fusion protein; however, unlike BCRABL1, this translocation is often a late event and amplification of the fusion transcript is necessary for oncogenicity. Furthermore, other additional classes of kinases have been identified as prerequisites for NUP214-ABL mediated neoplastic transformation. ABL1 and NUP214 are both located on chromosome 9 at 9q34; thus this is a cryptic translocation that cannot be detected on conventional karyotyping. It is not currently part of a standard
FISH work-up in T-cell lymphoblastic leukaemia/lymphoma; however, its presence may be suggested by detection of multiple copies of ABL1 due to episomal amplification of the fusion gene (using a BCR-ABL1 dual fusion probe set). The NUP214-ABL1 translocation can be confirmed by PCR. The significance of NUP214-ABL1 translocation is three-fold: molecular studies can be used for minimal residual disease (MRD) analysis; it may ultimately provide prognostic significance; and there is a potential role for tyrosine kinase inhibitors, in conjunction with standard chemotherapy. MOLECULAR ASPECTS OF AML William Stevenson Department of Haematology and Transfusion Medicine, Royal North Shore Hospital, Sydney, NSW, Australia Acute myeloid leukaemia (AML) is characterised by a clonal expansion of myeloid cells in the bone marrow with subsequent development of bone marrow failure. Current laboratory investigation for diagnostic AML samples in Australasia would typically include assessment of morphology, flow cytometry and cytogenetic analysis with consideration for targeted genetic testing of PML-RARA, CBF translocations, FLT3, NPM1 and CEBPA. This limited approach to genetic testing is likely to expand in coming years with increased knowledge of the AML genome. Driver mutations can now be identified in most AML samples with the interaction of multiple mutations in the same sample considered important for prognostication. The WHO classification of AML has increasingly relied on identification of these genetic lesions with the 2016 revision suggesting an increased number of diagnostic entities associated with recurrent genetic abnormalities as well as recognition that some of these identified mutations may represent underlying germ line changes that predispose to myeloid malignancy. The rapid improvement in sequencing technologies have allowed increasing genetic data to be obtained from cancer samples such that candidate gene panels are likely to offer improvements in leukaemia management with better disease prognostication, identification of targetable mutations for drug therapy and improved minimal residual disease detection. MINIMAL RESIDUAL DISEASE ASSESSMENT BY FLOW CYTOMETRY IN ACUTE LYMPHOBLASTIC LEUKAEMIA Janine Campbell Royal Children’s Hospital, Melbourne, Vic, Australia Minimal residual disease (MRD) assessment during the early stages of therapy for acute lymphoblastic leukaemia (ALL) is an important marker of prognosis. Contemporary paediatric protocols use MRD results for risk stratification, therapy assignment and post HSCT monitoring. Increasingly, MRD assessment is also being incorporated into treatment algorithms in adult ALL. As a result, diagnostic laboratories are being asked to introduce MRD analysis by flow cytometry. This presentation will cover various aspects of the MRD assay, including the establishment of lymphoid maturation templates using normal controls, quality control, and therapyinduced changes in leukaemia immunophenotypes. Common