Clinical characteristics of 15 children with mixed phenotype acute leukemia / 中华实用儿科临床杂志

ABSTRACT

Objective:To analyze the clinical characteristics, treatment and prognosis of mixed phenotypic acute leukemia (MPAL) in children, and to provide reference for clinical optimization of diagnosis and treatment and improve the remission rate.Methods:Based on the diagnostic criteria of the World Health Organization (WHO) in 2016, the bone marrow cell morphology, immune typing, cytogenetics, molecular biological characteristics, treatment regimen, and prognosis of 15 children with MPAL who were admitted to Children′s Hospital Affiliated to Soochow University from January 2012 to December 2020 were retrospectively analyzed.The count data were compared between groups using the χ2 test, the measurement data that conformed to the normal distribution were compared using the t test, and the measurement data that were not normally distributed were compared using the rank sum test.Survival was estimated using the Kaplan- Meier ( K- M) method and the Log- rank method was used for comparison. Results:A total of 15 children with MPAL were admitted to Children′s Hospital Affiliated to Soochow University in the past 8 years, including 8 males and 7 females, with a median age of 6.8 years.Nine patients expressed B lymphocyte and myeloid phenotype, 5 patients expressed T lymphocyte and myeloid phenotype, and 1 patient expressed B and T lymphocyte phenotype.Karyotype of 11 children was examined, and the results showed that there were 2 cases of normal karyotype, 2 complex karyotype, 6 pseudodiploid and 1 subdiploid.Fusion genes were detected in 5 children, including 3 AML- ETO positive, 1 BCR- ABL positive, and 1 MLL gene positive.Thirteen patients were in complete remission (CR) after chemotherapy, with a total CR rate of 86.6% and a 2-year over survival (OS) rate of (68.2±13.4)%.Among the 15 children, 14 received induction chemotherapy and 1 gave up treatment for personal reasons.There were 10 patients with the first choice of acute lymphoblastic leukemia (ALL) chemotherapy regimen and 1 patient receiving CR, with a total CR rate of 10%.There were 4 cases of acute myeloid leukemia (AML) with the preferred chemotherapy regimen and 3 cases with CR in the first course of treatment, and the total CR rate was 75%.One case without remission was relieved after changing ALL chemotherapy regimen.The 2-year OS rates of 8 patients with hematopoietic stem cell transplantation (HSCT) and 6 patients without HSCT were (70.0±18.2)% and (66.7±19.2)%, respectively, with no significant difference ( χ2=0.318, P=0.573). Conclusions:Children with MPAL is a rare malignant tumor, mainly characterized by the co-expression of lymphoid and myeloid antigens.Chemotherapy alone or HSCT can achieve a good prognosis in the short term, but the long-term efficacy remains to be further observed.