Human recombinant erythropoietic agents (rHuEPO) do not induce changes in circulating levels of endoglin and vascular endothelial growth factor (VEGF) in anaemic cancer patients

19569 Background: The expression of Erythropoietin (EPO) receptors on cancer cells and the correlation of EPO receptor levels with angiogenesis and progression in some cancers have suggested that EPO could acts directly as an angiogenic factor. The purpose of this study was to assess the effect of treatment with human recombinant erythropoietic agents (rHuEPO) in cancer patients with chemotherapy-induced anaemia on Endoglin and Vascular Endothelial Growth Factor (VEGF) circulating levels as a possible marker of angiogenesis. Methods: Endoglin and VEGF were measured in serum samples from 25 cancer patients with chemotherapy-induced anaemia before and after 3 to 4 weeks of treatment with rHuEPO (Epoetin alfa 150 UI/Kg three times per week; darbepoetin alfa 150 mcg/weekly). A group of 28 healthy voluntaries were used as control. Endoglin and VEGF were analyzed using an ELISA commercial Kit (R&D Systems; Ciudad-Pais). T- student test was used to study the association between variables. Paired comparisons before and after treatment were performed using the Wilcoxon rank-sum test. Results: VEGF serum levels were significantly higher in cancer patients than in controls (476,66±72,56 pg/ml versus 227,34±24,58 pg/ml, p<0.001, respectively). Endoglin levels were significantly higher in patients than controls, although this difference did not reach statistical significance (4.75±0.30ng/ml versus 4.18±0.12 ng/ml, p=0.075). Similar results were found in the different subgroups of patients (Breast cancer, endoglin p=0.019; VEGF p=0.009; Colon cancer, endoglin p=0.084; VEGF p<0.001). Using the Wilcoxon rank-sum test no statistically significant differences in endoglin (p=0.510) and VEGF (p=0.313) serum levels were found between samples obtained before and after treatment with rHuEPO agents. When considering the type of rHuEPO, no differences were observed. In a similar manner, no difference was observed depending on chemotherapy regimen or cancer type. Conclusions: Although the follow up is short and the number of patients is small, our exploratory results do not support that rHuEpo treatment in anaemic cancer patients induce angiogenic serum markers. No significant financial relationships to disclose.