Mixed-phenotype acute leukemia: suboptimal treatment when the 2008/2016 WHO classification is used

Abstract

BackgroundDifferent criteria have been used to diagnose mixed-phenotype acute leukemia (MPAL), which has impacted the number of individuals diagnosed with this pathology. Better outcomes have been reported when using acute lymphoblastic leukemia (ALL)-type chemotherapy in the treatment of MPAL.MethodsWe compared the outcome of 4 groups of patients with MPAL. Group 1 included patients diagnosed using the 2008/2016 World Health Organization (WHO) classification; group 2 included patients diagnosed using the European Group for the Immunological Characterization of Leukemias (EGIL) criteria; group 3 included patients diagnosed using either the EGIL or the 2008/2016 WHO criteria; and group 4 was comprised of patients diagnosed with MPAL using the EGIL classification only.ResultsWe found a significantly worse disease-free survival (groups 1-4) and overall survival (OS) (groups 2 and 3) when comparing MPAL patients to other acute leukemia (AL) patients. A significantly better OS was obtained in patients (groups 2-4) treated with ALL-type chemotherapy compared to acute myeloid leukemia (AML)-type regimens.ConclusionIn light of these results, and because a trend (P=0.06) was found with regard to a better OS in group 4 when compared to other AL patients, an argument can be made that the 2008/2016 WHO classification is underpowered to diagnose all MPAL cases, potentially resulting in the suboptimal treatment of some individuals with AL.

Mixed‐phenotype acute leukemia: A cohort and consensus research strategy from the Children’s Oncology Group Acute Leukemia of Ambiguous Lineage Task Force

“…However, many of the analyses included MPAL diagnosed according to either the World Health Organization (WHO) classification system or the European Group for Immunological Characterization of Acute Leukemias (EGIL) classification system. Within AMBI2012 and other cohorts, the varying classifications for MPAL and even updated versions of the same classification demarcate different populations and influence survival estimates . To best understand treatment effects within a uniformly defined MPAL population, we, therefore, assembled a cohort strictly defined only by the most recent WHO classification (World Health Organization 2016 [WHO2016]) …”

Mixed phenotype acute leukaemia: a case report of an unusual presentation

“…[2][3][4][5] The 2008 World health organization classification and European group for the immunological characterization of leukaemias (EGIL) have laid down certain criteria which must be met in order to diagnose a case as mixed phenotype acute leukaemia, thus helping in distinguishing them from acute lymphoblastic leukaemia or acute myeloid leukaemia with aberrant antigen expression. 6 An acute clinical awareness can prevent an erroneous diagnosis especially when MPAL manifests with generalized lymphadenopathy, as seen in the case we describe here.…”

Ostra białaczka z koekspresją antygenów limfo- i mieloidalnych oraz masywną limfadenopatią jako problem diagnostyczny i terapeutyczny

“…[7] wskazali na znacznie krótsze mediany przeżycia wolnego od choroby (DFS, disease-free survival) i przeżycia całkowitego (OS, overall survival) wśród pacjentów z ostrą białaczką o mieszanym fenotypie w porównaniu z chorymi na inne postacie ostrych białaczek: DFS 6 miesięcy i OS 8 miesięcy w przypadku MPAL, następnie odpowiednio DFS 9 miesięcy i OS 13 miesięcy u pacjentów z ALL oraz DFS 9 miesięcy i OS 18 miesięcy u chorych na AML. Równocześnie stwierdzono dłuższe OS u pacjentów leczonych chemioterapią typu ALL w porównaniu ze schematami typu AML [7,18]. Tych obserwacji, choć zgodnych z wcześniejszymi doniesieniami, nie uznano za jednoznaczne wskazanie, aby pacjentów z MPAL leczyć według protokołów zalecanych dla ALL [18][19][20][21].…”

“…Kryteria klasyfikacji ostrej białaczki bifenotypowej według European Group for Immunological Classification of Leukemia (EGIL); wymagane ponad 2 punkty dla co najmniej dwóch linii komórkowych: limfocytów B, T lub mieloidalnej (źródło[1,7]) European Group for Immunological Classification of Leukemia (EGIL) scoring system for biphenotypic acute leukemia; score greater than 2 is required for at least 2 lineages: B, T lineage or myeloid (source[1,7]) ALL włączono ją do klasyfikacji ostrych białaczek według WHO w 2016 roku.…”