PB1952 ADDITIONAL CYTOGENETIC ABNORMALITIES IN RESOURCE CONSTRAINT COUNTRIES; AN ADDITIONAL BURDEN ON CHRONIC MYELOID LEUKEMIA PATIENTS?
Authors: Anwar N. , Fatima N. , Nadeem M. , Shamsi T. 
Published: June 2019

Background:

Chronic Myeloid Leukemia (CML) is a myeloproliferative neoplasm distinguished by the presence of philadelphia chromosome. Regardless of distinct cytogenetic and molecular features possessed by disease; the patients present diversely with respect to clinical presentation, treatment response and survival. In addition, the heterogeneous characteristics of CML are also evident at cytogenetic and molecular levels. Most CML patients harbor the classic Ph; however, 5% to 10% of patients have variant translocations in which at least a third chromosome is involved in the rearrangement addressed as additional cytogenetic abnormalities (ACA). Previous studies have reported a negative prognostic impact of these abnormalities on molecular/cytogenetic response and survival in patients but these findings are conflicting and ambiguous. The option to omit the cytogenetic assessment has been presented in 2013 ELN recommendation however they stated to perform cytogenetics until the achievement of complete cytogenetic and major molecular responses.

Aims:

The rationale of the study was to follow the patients identified with ACA at baseline before the initiation of therapy, assess their clinical outcome, response to treatment and observe if there is any difference in molecular response from the cohort not identified with ACAs at baseline.

Methods:

A case control study carried out at National Institute of Blood Diseases and Bone Marrow Transplant Karachi Pakistan from 2016 to 2018. Participants included 18 CML cases with additional cytogenetic abnormalities. For each case, 02 controls were taken. Controls were diagnosed CML patients without additional cytogenetic abnormalities. Response to treatment was assessed according to ELN recommendations 2013. The study was approved by institutional review board. Descriptive and inferential statistics including chi square and paired t test was applied by using SPSS version 23.0.

Results:

Fifty four participants were included in the study. Of these, 18 were diagnosed cases of CML having additional cytogenetic abnormalities, and 54 were taken as age, sex and sokal score matched controls CML patients without additional cytogenetic abnormalities. Post treatment response was assessed in cases and controls which revealed that both the groups had same response to treatment with respect to increment in Hemoglobin levels and normalization of TLC and platelet counts (P‐value < 0.05.) Complete hematological response at 03 months was achieved by higher number of subjects in control group than cases (P‐value < 0.05). Fifteen cases and 30 controls were evaluable for molecular response. Attainment of optimal response at 06 months was same in cases and controls (P‐value >0.05) while at 12 months, those who had achieved optimal response were higher in numbers in controls than cases (P‐value <0.05). Comparable percentage of participants in cases and controls sustained molecular response till their last follow up (P‐value >0.05).

Summary/Conclusion:

Patients with additional cytogenetic abnormalities in our cohort showed similar hematological and molecular response as controls. In developing countries with limited resources, financial constraints and scarce medical facilities, omission of cytogenetic analysis at baseline when molecular level tests are available will create no difference in decisions to be taken in the management of CML patients. However, further perspective studies are needed in this regard.