Mixed-phenotype acute leukemia: suboptimal treatment when the 2008/2016 WHO classification is used
Alan Pomerantz1,2, Sergio Rodriguez-Rodriguez1,2, Roberta Demichelis-Gomez1, Georgina Barrera-Lumbreras1, Olga Barrales-Benitez1, Xavier Lopez-Karpovitch1, Alvaro Aguayo-Gonzalez1
1Department of Hematology and Oncology, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Tlalpan, Mexico City,
2Faculty of Health Sciences, Universidad Anahuac Mexico Norte, Huixquilucan, State of Mexico, Mexico
Correspondence to: Alvaro Aguayo-Gonzalez, M.D.
Department of Hematology and Oncology, Instituto Nacional de Ciencias Medicasy Nutricion Salvador Zubiran, Vasco de Quiroga 15, Col. Belisario Dominguez Seccion XVI, Del. Tlalpan, C.P. 14080, Mexico City, Mexico
Received: July 14, 2016; Revised: September 20, 2016; Accepted: October 7, 2016; Published online: December 31, 2016.
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Background Different 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. Methods We 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. Results We 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. Conclusion In 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.
Keywords: Mixed-phenotype acute leukemia, WHO classification, EGIL classification, Suboptimal treatment