Angiogenic Cytokines: Vascular Endothelial Growth Factor and Basic Fibroblast Growth Factor Levels in Serum of Children with Hematopoietic Malignancies and Solid Tumors.

Angiogenesis is a process of blood vessel formation from the preexisting capillaries. It plays an essential role of growth and development of cancer. The most important angiogenic stimulators are Vascular Endothelial Growth Factor (VEGF) and basic Fibroblast Growth Factor (bFGF). The aim of the study was to evaluate the serum levels of VEGF and bFGF in children with solid tumors, hematological malignancies and in healthy controls. Patients: 110 children (33 with solid tumors and 77 with hematological malignancies, including 46 with acute lymphoblastic leukemia and 17 with acute myeloblastic leukemia) (56 male and 54 female) aged 2–18 years (median 8.5 years) and 70 healthy controls (31 male and 39 female) aged 3–18 years (median 13 years). For the quantitative determination the Quantikine VEGF and bFGF immunoassay, a solid-phase enzyme-linked immunosorbent assay method was used. Elevated VEGF and bFGF were defined as being higher than the 95 percentile value in control group. Results: At the time of diagnosis the range of VEGF serum levels in all cancer patiens was 0–2691.3 pg/ml, and in remission 6.08–967.67 pg/ml; while the range of bFGF at diagnosis was 0–64.48 pg/ml, and in remission 0–32.52 pg/ml. In all children with cancer, serum levels of VEGF and bFGF were significantly more often elevated than in healthy controls (p<0.004; p<0.0005). At diagnosis, almost 12% patients had simultaneously elevated serum levels of VEGF and bFGF. Among patients with solid tumors at the time of diagnosis, elevated levels of VEGF and bFGF was observed in 42% and 60%, respectively. There were no differences between serum levels of these factors in patients in remission and in control group. In patients with progression, serum levels of VEGF and bFGF were higher, when compared to levels of these factors at diagnosis. The range of serum levels of VEGF in children with solid tumors at the time of diagnosis was 85.96–2691.3 pg/ml (median 365.48 pg/ml), and in remission 6.08–787.16 pg/ml (median 204.1 pg/ml). The median level of VEGF at diagnosis in children with hematopoietic malignancies (range 0–1869.6 pg/ml, median 111.6 pg/ml) was lower than in children with solid tumors (p<0.0005). In children with acute leukemias at diagnosis, serum levels of VEGF were significantly lower than in children with lymphomas (p<0.0003) and in controls (p<0.05). These results suggest that evaluation of serum levels of VEGF and bFGF can be helpful for monitoring activity of cancer, particularly in solid tumors and in the future can be a target of anti-angiogenic therapy.