The significance of FMS-Like Tyrosine Kinase 3 surface receptor expression in acute myeloblastic leukemia and precursor B-acute lymphoblastic leuke...

Date 20 October 2018
Event ESMO 2018 Congress
Session Poster display session: Biomarkers, Gynaecological cancers, Haematological malignancies, Immunotherapy of cancer, New diagnostic tools, NSCLC - early stage, locally advanced & metastatic, SCLC, Thoracic malignancies, Translational research
Topics Leukaemia
Presenter Suzan Al Hassanin
Citation Annals of Oncology (2018) 29 (suppl_8): viii359-viii371. 10.1093/annonc/mdy286
Authors S.A. Al Hassanin1, I.A. Ahmedy2
  • 1Clinical Oncology, Faculty of Medicine - Menoufia University, 32511 - Shebin El Kom/EG
  • 2Clinical Pathology Department, Faculty of Medicine - Menoufia University, 32511 - Shebin El Kom/EG

Abstract

Background

FMS-Like Tyrosine Kinase III (FLT3 / CD135), also known as stem cell tyrosine kinase 1 (STK1) or fetal liver kinase 2 (FLK2), belong to the group of class3 receptor of tyrosine kinase activity. The expression of FLT3 receptor is confined to early hematopoietic progenitor’s cells in normal BM. Even though new FLT3 mutations in Acute Myeloid Leukemia (AML) are increasing, the role of FLT3 receptor surface expression in AML and precursor B acute lymphoblastic leukemia (pre-B-ALL) had infrequently been addressed.

Methods

To further evaluate the significance of FLT3 (CD135) expression in AML and pre B-ALL we investigated FLT3 level of expression in newly diagnosed 76 AML patients, 80 pre B-ALL patients and 72 healthy control donors by flowcytometry. The cut-off value for FLT3 positivity was 20%. FLT3 expression was correlated with standards prognostic parameters.

Results

We demonstrated FLT3 protein expression >20% in 68.4% of AML patients, its level was different in FAB subtypes with increasing levels in the following order: M1+/34+, CD117+ and high LDH. Finally, FLT3 +correlated with poor clinical outcome, shorter disease-free survival and overall survival than FLT3-, Regarding pre B-ALL, FLT3+ protein expression >20% was 65%. It correlated with age ≤10 years, with absence of lymphadenopathy and absence of CNS infiltration, high percentages of bone marrow blasts, leukocyte counts ≤50 ×103. Furthermore, it correlated with CD 10+, CD34+. Finally, FLT3+ correlated with good clinical outcome, longer free disease survival and overall survival than FLT3-.

Conclusions

High FLT3 expression can predict outcome and is associated with poor prognostic factors in AML while it is associated with good prognostic factors in ALL.

Clinical trial identification

Legal entity responsible for the study

Faculty of Medicine, Menoufia University, Shebin Elkom, Egypt.

Funding

Has not received any funding.

Editorial Acknowledgement

Disclosure

All authors have declared no conflicts of interest.