Prognostic Features of BCR-ABL Genetic Variations in Acute Lymphoblastic Leukemia

Background: Acute lymphoblastic leukemia (ALL) is a hematologic malignancy which results from accumulation of lymphoid progenitor cells in the bone marrow and/or extramedullary sites. Philadelphia chromosome (Ph1) positive ALL, a high-risk cytogenetic subset, accounts for 25% - 30% of adult ALL cases but occurs in less than 5% of children. We aimed with this study to detect BCR-ABL genes fusion, amplification and deletion in ALL patients, using extrasignal-fluorescence in situ hybridization (ES-FISH), and to assess their relation with other standard prognostic factors and therapeutic response. Patients and Methods: This study was carried out on 39 newly diagnosed ALL patients. All patients were subjected to: history, clinical examination and laboratory investigations, which included complete blood count (CBC), peripheral blood (PB), bone marrow (BM) examination, immunophenotyping and fluorescence in situ hybridization using extra-signal probe to detect BCR-ABL genes fusion. Results: This study showed statistical analysis of patients’ t(9; 22) with other factors revealed, significant association (p < 0.05) of t(9; 22) with patients outcome, age > 35 years, hepatosplenomegaly, absence of lymphadenopathy, TLC ≥ 50 × 109/L, absolute PB blasts ≥ 4.4 × 109/L, immunophenotyping and other aberrations. Conclusion: BCR/ABL fusion gene analysis by ES-FISH may serve as a prognostic marker in adulthood ALL. The age, TLC and t(9; 22) represent the significant standard prognostic factors in relation to patients’ outcome.