Induction Chemotherapy Response in Childhood Acute Lymphoblastic Leukaemia and its Correlation with Cytogenetic and Molecular Features.

OBJECTIVE

To study the correlation of cytogenetic and molecular abnormalities on induction chemotherapy in childhood acute lymphoblastic leukaemia (ALL).

STUDY DESIGN

Analytical study.

PLACE AND DURATION OF STUDY

Department of Haematology, Armed Forces Institute of Pathology (AFIP), from March 2021 to August 2021.

METHODOLOGY

Patients aged 1-18 years with newly diagnosed acute lymphoblastic leukaemia were inducted. Patients aged less than 1 year and more than 18 years were excluded from the study. The diagnosis was based on morphology, cytochemistry, flow cytometry, and cytogenetic/molecular analysis. Risk stratification was done on the basis of age, TLC, and cytogenetic/molecular defects. The UKALL 2011 protocol was used for treatment with regimen-A for standard risk and regimen-B for high-risk patients. Bone marrow was repeated on day 29 of induction therapy and blast percentage was assessed to establish post-induction remission. Association between cytogenetic / molecular abnormalities and post-induction remission status was analysed using chi-square test.

RESULTS

There were total 142 patients with mean age of 6.4 + 3.6 years and a male- to-female ratio of 2.7:1. Immunophenotyping revealed 85.9% cases as B-cell ALL and 14.1% as T-cell ALL. The most frequent cytogenetic and molecular abnormalities were hyperdiploidy (19%), t(9;22)/BCR-ABL1(p190) (10.6%), complex karyotype (5.6%), E2A-PBX1 (8.5%), and TEL-AML1 (4.9%). A total of 127/142 (89.4%) achieved haematological remission after induction therapy with two deaths during induction therapy (1.4%). Post-induction remission rate in patients with favorable cytogenetic/molecular defects was 100% and in children with bad prognostic changes, the rate of remission was 69.2%. Chi-square test showed a significant association between cytogenetic/molecular abnormalities and post-induction remission (p-value <0.001).

CONCLUSION

Cytogenetic and molecular abnormalities have a significant association with post-induction remission in children with acute lymphoblastic leukaemia.

KEY WORDS

Acute lymphoblastic leukaemia, Cytogenetics, Chemotherapy, Induction, Remission.