The pheno-genotypic characteristics of infantile acute leukemia in a regional cancer center from South India

Abstract

Introduction: Acute leukemia (AL) is uncommon in infants, with an annual incidence of 30 per million live births. They have peculiar biological characteristics. Although remarkable progress is seen in treatment of childhood AL, infantile AL remains a resistant subset with a dismally low 4-year survival of 35%. Objectives: To study the morphological, immunophenotypic, and cytogenetic features of infantile AL. A retrospective study of AL cases in children from birth up to 1 year of age, presenting to the departments of pediatric oncology and hematopathology between January 2010 and April 2015, was conducted. Results: Thirty-eight cases of infantile AL were included. The mean age at presentation was 10.2 months, and a female preponderance (M–F ratio: 0.65:1) was noted. Hyperleukocytosis (total white cell count >50 × 109/mm3) was seen in 13 (39.4%) cases. Immunophenotyping done in 31 cases showed pre-B acute lymphoblastic leukemia (B ALL) in 18 (58%), pre-T ALL in three (9.7%), and acute myeloid leukemia (AML) in 10 (32.3%). CD10 positivity was seen in 12 (57.1%) cases of ALL. Cytogenetic study done in 34 cases showed AML with recurrent genetic abnormalities in four. Mixed lineage leukemia (11q23) abnormality was seen in three cases of ALL. Two cases of AML were associated with trisomy 21. One case with features of AML M7 in a 4-day-old baby turned out to be transient abnormal myelopoiesis on follow-up. Conclusion: Literature on infantile AL from Indian studies is scarce compared to the available Western literature. Hence an epidemiological study of AL cases was done with review of literature, in an attempt to understand their pheno-genotypic features that influence their behavior. This may help in standardizing the treatment of these rare cases.