Elevated serum endostatin levels are associated with favorable outcome in acute myeloid leukemia

Abstract

Background: Endostatin is the C-terminal antiangiogenic fragment of the extracellular matrix protein collagen XVIII, and is generated by tumor-derived proteases. The levels and the prognostic relevance of serum endostatin in acute myeloid leukaemia (AML) patient are not fully clear.Objective: The aim of this study was to evaluate serum levels of endostatin in acute myeloid leukemia patients before chemotherapy and after achieving complete remission and to correlate endostatin levels with patient outcome.Materials and methods: Serum samples from 30 adult patients (22 males and eight females, median age 37, range 19–66 years) with AML had been taken before chemotherapy was administered. In addition 25 out of 30 patients were reinvestigated again at complete remission (CR). Ten samples from healthy normal persons of matched age and sex were evaluated as a reference control group. Serum endostatin levels were determined using enzyme linked immune sorbent assay (ELISA).Endostatin serum levels were not significantly different in the pre-treatment AML patients as compared to that in normal controls (p>0·05). In AML patients the baseline endostatin levels were significantly lower than at CR (p=0·001).Results: No significant relation were detected between pre-treatment serum endostatin levels and age, peripheral blood white cell counts, platelet counts, bone marrow blast cell counts, blast cell distribution ratio or cytogenetic findings. The prognostic value of serum endostatin (sE) was also evaluated by dividing AML patients into high and low sE groups using the 75 percentile sE levels of the patients group as cutoff. The authors found that patients group in the high sE group survived for significantly longer time than those patients in the low sE group.Conclusion: Elevated endostatin levels at AML diagnosis is a good prognostic marker for patients' outcome. Wide scale study is recommended in order to establish the clinical value of this study.