Serum vascular endothelial growth factor as a significant marker of treatment response in pediatric malignancies.

The aim of this pilot study was to determine VEGF serum levels (S-VEGF) at diagnosis and at restaging in children diagnosed with cancer, and to investigate whether this parameter provides prognostic information for remission after induction therapy and response to treatment. S-VEGF levels of 35 consecutive pediatric patients with various types of cancer were assayed at diagnosis and at restaging. Levels of VEGF were determined using a commercially available ELISA anti-human VEGF immunoassay kit. Thirty-one children went into complete remission or had a very good partial response to first-line therapy; 4 patients developed tumor progression. At diagnosis average S-VEGF level was 495 pg/mL (range, 0.89--2220 pg/mL) and at restaging it decreased to 118.36 pg/mL (range, 7.44--487 pg/mL). (p=.0039). The 4 patients with tumor progression had increased S-VEGF levels at restaging. The comparison between the levels of S-VEGF at diagnosis and at restaging showed a significant difference for the patients who responded to treatment with decreased S-VEGF and the patients who developed tumor progression with increased S-VEGF (p=.0019). One child with metastatic Ewing sarcoma developed progressive disease after several weeks, with significantly progressively higher S-VEGF levels. One child with Hodgkin disease, who had a higher level at first restaging and developed progressive disease, responded to reinduction therapy and had a significantly lower level at the second restaging. The child with metastatic hepatoblastoma responded to first-line chemotherapy with concomitant decrease in S-VEGF and alpha-fetoprotein levels, but developed local recurrence with elevation in both parameters. Changes in S-VEGF levels correlated with response to treatment for most of the children diagnosed with cancer. This provides a rationale for exploring clinical interest in S-VEGF measurements of a larger group of children with malignancies, and using the test for clinical trials of antiangiogenic therapies.