Distribution of Chromosomal Abnormalities Commonly Observed in Adult Acute Myeloid Leukemia in Pakistan as Predictors of Prognosis

ABSTRACT

Objectives: The heterogenous response to treatment in acute myeloid leukemia (AML) can be attributed largely to the difference in cytogenetic features identified in between cases. Cytogenetic analysis in acute leukemia is now routinely used to assist patient management, particularly in terms of diagnosis, disease monitoring, prognosis and risk stratification. Knowing about cytogenetic profile at the time of diagnosis is important in order to take critical decisions in management of these patients. The study was conducted to determine the distribution of cytogenetic abnormalities in Pakistani adult patients with AML in order to have insights regarding behavior of the disease. Methods: A retrospective analysis of all the cases of AML (≥15years old) diagnosed at Aga Khan University from January 2011 to December 2016 was performed. Cytogenetic analysis was made for all cases using the trypsin-Giemsa banding technique. Karyotypes were interpreted using the International System for Human Cytogenetic Nomenclature (ISCN) criteria. Results: A total of 321 patients were diagnosed with AML during the study period, of which 288 samples successfully yielded metaphase chromosomes. The male to female ratio was 1.71. A normal karyotype was present in 61% (n=176) of the cases whereas, 39% (n=112) had an abnormal karyotype. Of the abnormal cases, t (8;21) (q22;q22) and t (15;17) (q22;q12) were identified in 8.3% and 4.9% cases respectively. Adverse prognostic cytogenetic subgroups including complex karyotype, monosomy 7 and t(6;9)(p23;q34) were identified in 9%, 1% and 0.7% patients respectively. Conclusions: This largest cytogenetic data in adult AML from Pakistan showed comparable prevalence of favorable prognostic karyotype to international data. The prevalence of specific adverse prognostic karyotype was low.