Prognostic evaluation of the microvascular network in myelodysplastic syndromes

Considering the recently stated suggestion of neovascularization being impl icated in myelodysplastic syndromes (MDS) pathogenesis, we evaluated multip le morphometric microvascular characteristics in MDS, in relation to clinic opathologic factors and prognosis. Trephines from 50 newly diagnosed MDS pa tients were immunostained for factor VIII and compared to those from 20 con trols, 10 chronic myelomonocytic leukemia (CMML) and 12 acute myeloid leuke mia (AML) patients. Quantitation of microvessel density (MVD), area, total vascular area (TVA), major and minor axis length, perimeter, compactness, s hape factor, Feret diameter, and the number of branching vessels was perfor med by image analysis. Overall, the MDS group had significantly higher MVD, TVA, minor axis and shape factor values and significantly lower compactnes s than the control group. AML was characterized by increased vascularity co mpared to MDS and CMML, as well as by the presence of flattened microvessel s (lower values of shape factor). Hypercellular MDS showed higher MVD. RA/R ARS displayed larger caliber vessels than RAEB, which explains the favorabl e prognostic effect of increased size-related parameters on progression and /or survival. Moreover, decreased compactness and MVD were independent pred ictors of longer progression-free survival. It is concluded that angiogenes is is involved in the conversion of normal marrow to MDS and ultimately to AML and that disease progression within MDS is accompanied by qualitative a lterations of the microvascular network. Furthermore, size-related paramete rs affect survival, while shape-related parameters and MVD are more influen tial with regard to progression-free survival.