The Impact of Endothelial Cell Values in Bone Marrow on the Survival of Patients with Multiple Myeloma—A Single-Center Observational Study

<b>Background:</b> This study aimed to analyze the survival of patients with multiple myeloma in relation to the value of endothelial cells involved in the process of tumor neoangiogenesis. <b>Methods:</b> In this non-randomized observational study, we prospectively evaluated a cohort of 74 adult patients with multiple myeloma who underwent a baseline assessment of the endothelial cell count in their bone marrow and received VCD or VTD anti-myeloma therapy followed by autoPBSCT. They were then evaluated for survival via long-term follow-up. <b>Results:</b> The survival of myeloma patients undergoing these therapies was analyzed, and we found that patients with higher endothelial cell counts had higher mortality rates during long-term follow-up. In the group of patients who died, the endothelial cell count was significantly higher (<i>p</i> = 0.024). We also observed that patients who initially had >2 osteolytic lesions had higher endothelial cell counts (<i>p</i> = 0.021). However, our analysis of endothelial cell count in relation to patient survival using antiangiogenic drugs showed that, in this group, the endothelial cell count was significantly higher in patients who died (<i>p</i> = 0.048). <b>Conclusions:</b> We found that patients with higher endothelial cell counts and those who did not receive antiangiogenic drugs from the start of therapy had higher mortality rates during long-term follow-up.