BACKGROUND: Philadelphia chromosome-like acute lymphoblastic leukemia (Ph'-like ALL) is characterized by a gene-expression profile similar to that of BCR-ABL1 positive ALL and a poor outcome. Rearrangements of cytokine receptor like factor 2 (CRLF2) are identified in approximately 50% of Ph'-like and 10% of B-other ALL patients.

AIM: To identify the incidence of CRLF2 rearrangements and the frequency of relapse in a cohort of B-other Precursor B-ALL adults Egyptian patients who were treated with conventional therapy at National Cancer Institute, Cairo University.

METHODS: The routine diagnostic work-up at diagnosis included Bone marrow aspiration, immunophenotyping, karyotyping, fluorescent in situ hybridization (FISH) for BCR-ABL1 and KMT2A (MLL) and CRLF2 rearrangements (IGH-CRLF2 or P2RY8-CRLF2), and molecular analyses of BCR-ABL1 translocations. Patients within the age group 18-25 years received Total XV protocol while patients >25 years received Hoelzer's protocol.

RESULTS: Forty patients were included (22 males, 18 females). Median age at diagnosis was 25 years (18 -65). Median TLC was 14.9 x109/L (1.1 - 201), median Hb was 9.9 gm/dl (5-12.9), median platelet count was 47 x 109/L (19-359) and median BM blasts count was 90% (30-100). CRLF2 rearrangement was detected in 4/40 (10%) patients. All CRLF2 positive patients (100%) relapsed at 6 months vs. 11/36 (30%) CRLF2 negative (p<0.001). At 6 months follow up, disease free survival (DFS) was 70% in CRLF2 negative patients vs. 0% in CRLF2 rearranged (p=0.04). At 1 year follow up, overall survival (OS) was 30 (75%) for CRLF2 negative vs. 0 (0%) for CRLF2 positive patients (p=0.01).

CONCLUSION: CRLF2 rearrangements constitute a high risk independent prognostic factor in adult precursor B-ALL patients denoting a poor outcome and should be studied in ALL Ph' negative patients. Additional TKI therapy should be included for this category of patients in our protocols to improve outcome.

Figure.
Figure.
View largeDownload slide
Disclosures

No relevant conflicts of interest to declare.

Topics:
acute lymphocytic leukemia, burkitt's lymphoma, follow-up, leukemia, b-cell, acute, bone marrow aspiration, immunophenotyping, karyotype determination procedure, prognostic factors, protein-tyrosine kinase inhibitor, receptors, cytokine

Author notes

*

Asterisk with author names denotes non-ASH members.

© 2018 by The American Society of Hematology
2018
Sign in via your Institution