Bone marrow angiogenesis in multiple myeloma and its correlation with clinicopathological factors

Increased angiogenesis has been found to be an adverse prognostic factor in solid tumors but evidences show that angiogenesis also plays an important role in hematological malignancies including multiple myeloma (MM). In this report we studied the various angiogenesis parameters like microvessel density (MVD) and total vascular area (TVA), on bone marrow biopsies in 50 newly diagnosed cases of MM. The aim was to study bone marrow angiogenesis in MM using light microscopy (MVD-A) and computerized image analyzer (MVD-B and TVA) and correlate it with clinical features, laboratory findings, histological features, and response to treatment on follow-up. Bone marrow biopsies of test cases (n = 50) were immunohistochemically stained with CD34 for visualization of microvessels. MVD-A (range 8-80; mean 50.4; SD 17.5), MVD-B (5.2-33.2; mean 16.3; SD 5.1), and TVA in percentage (range 0.42-7.20; mean 2.8; SD 1.5) were measured. Ten age- and sex-matched controls were studied and their parameters were taken as grade I. There was a significant correlation between these angiogenesis parameters (MVD-A vs MVD-B, Pearson's correlation coefficient (pcc) = 0.724; MVD-A vs TVA, pcc = 0.370; MVD-B vs TVA, pcc = 0.406). The angiogenesis was significantly higher in cases as compared to controls. Patients with residual disease had a higher MVD as compared to the complete responders. High tumor burden and diffuse pattern of infiltration were also associated with grade III MVD and TVA. Hence, it can be concluded that angiogenesis correlates with other histological features associated with prognosis and is also a good predictor for complete response in patients with multiple myeloma.