Correlation between Additional Cytogenetic Abnormalities and Clinical Outcome in Chronic Myeloid Leukemia

Introduction: Chronic myeloid leukaemia (CML) is a clonal myeloproliferative disorder characterized by massive proliferation of myeloid cell line with normal differentiation. The focus of mechanism is a balanced translocation t(9;22)(q34;q11.2) resulting in BCR-ABL1 oncogene. Additional cytogenetic abnormalities (ACAs) have been observed during transformation of chronic myeloid leukaemia from chronic to terminal phases is supposed to play a pivotal role in disease progression.

Materials and Methods: We conducted a prospective observational study including 100 patients of newly diagnosed Philadelphia positive chronic myeloid leukaemia. Patients were followed up for 12 months.

Results: The prevalence of additional cytogenetic abnormalities was 8 percent. Additional cytogenetic abnormalities positivity was associated with an increased mean value of Sokal score when compared to additional cytogenetic abnormality negative patients. At the end of 12 months, 62.50% of additional cytogenetic abnormalities positive patients showed progression to a more advanced phase compared to 7.61% in the additional cytogenetic abnormalities negative subgroup. 77.17 percent of additional cytogenetic abnormalities negative patients and 25 percent of additional cytogenetic abnormalities positive patients were in remission at the end of 12 months.

Summary: Presence of additional cytogenetic abnormalities at initial diagnosis of chronic myeloid leukemia is associated with a higher risk of progression to an advanced phase. Early identification of these abnormalities may help in designing a more appropriate therapeutic approach.