Outcomes in Patients With Mixed Phenotype Acute Leukemia in Morocco

Abstract

Mixed phenotype acute leukemia (MPAL) includes biphenotypic and bilineal types of leukemia, which constitute rare subtypes that require individualized therapy. Outcomes in Moroccan patients with MPAL are unknown. Among 1264 patients with acute leukemia, 20 were classified as having MPAL, including 17 with biphenotypic acute leukemia (1.3%) and 3 with bilineal leukemia (0.2%). There were 8 adults and 12 children. In 12 cases (60%), leukemic blasts expressed myeloid and T-lymphoid antigens, and, in 5 cases (25%), leukemic blasts expressed B lymphoid antigens plus myeloid antigens. Patients were initially treated on protocols for acute myeloid leukemia (n=4), acute lymphoblastic leukemia (ALL, n=14), or with palliative care (n=2). The probability of survival at 2 years in MPAL cases was 52%± 14%. Six of the 12 patients younger than 15 years remain alive versus 1 of 8 adult patients. Patients treated with ALL-directed therapy had significantly higher overall survival than those treated with acute myeloid leukemia-directed therapy (P=0.003). There was no association between the phenotypic characteristics and the clinical outcome (P=0.83). In conclusion, MPAL represents 1.5% of acute leukemia in Morocco. The prognosis is poor, but initial treatment with therapy directed toward ALL, improved supportive care, and the prevention of abandonment of therapy may improve outcomes in this subgroup of patients.

The Relationship between Clinical Feature, Complex Immunophenotype, Chromosome Karyotype, and Outcome of Patients with Acute Myeloid Leukemia in China

“…Our results also showed a high incidence of Philadelphia chromosome positive (21.6%) or BCR-ABL translocation (20.6%) in MPAL, which was consistent with the report by Atfy et al [ 13 ]. As reported by Matutes et al [ 12 ] and Bachir et al [ 14 ], we also observed a high incidence of cytogenetic abnormalities in MPAL with only a small number of the cases displaying a normal karyotype.…”

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

“…The COG MPAL cohort described here, the iBFM AMBI2012 registry study, and the few pediatric case series for MPAL all suggest that beginning with ALL therapy results in similar or greater OS in comparison with AML regimens. A recent meta‐analysis of patients with MPAL also reported a survival benefit from starting with ALL therapy, although patient‐level data revealed equivalent OS with AML therapy .…”

“…Because of the rarity of pediatric MPAL, reports limited to children and adolescents are sparse . Similarly to the AMBI2012 registry, the strength of the cohort presented here is the use of a central review of immunophenotyping, which was supplemented as necessary with additional characterization from residual banked samples.…”

“…Past reports on MPAL suggest that contemporary ALL treatment regimens may be sufficient to cure many, if not most, pediatric patients with MPAL . However, the majority of these case series have lacked central review and, despite age‐associated differences in survival, included only aggregate pediatric and adult data .…”

Mixed phenotype acute leukemia: Biological profile, clinical characteristic and treatment outcomes: Report of the population‐based study

“…Most cases of acute leukemias (AL) can be assigned a specific differentiation along a single lineage according to morphology, cytochemistry, comprehensive panel of immunological markers karyotyping, and molecular genetic analyses. However, there are uncommon cases of patients with AL having immunophenotypic feature characteristics of >1 cell lineage without any specific genetic aberrations contributing to myeloid or lymphoid phenotypes 1‐3 …”