A substance that has been studied in the treatment of cancer. It binds to the RNA for a protein called vascular endothelial growth factor (VEGF) that stimulates the growth of new blood vessels. VEGF-AS blocks the cell?s ability to make VEGF, which may kill tumors that need new blood vessels to grow. It is a type of antisense oligonucleotide and a type of gene expression inhibitor. Also called vascular endothelial growth factor-antisense oligonucleotide.