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

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 AML patient is not fully clear.

To evaluate serum levels of endostatin in acute myeloid leukemia patients before chemotherapy and after achieving complete remission and to correlate endostatin levels with patients outcome.

Serum samples from 30 adult patients (22 males and 8 females, median age 37, range 19-66 years) with AML had been taken before chemotherapy was administered. In addition 20 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 pretreatment 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). No significant correlation were detected between pretreatment serum endostatin levels and age, peripheral blood white cell counts, platelet counts, bone marrow blast cell counts, blast cell distribution ratio. The prognostic value of 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.

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.