His hope is to catch a tumor cell in the act of making its exodus. The angiogenesis revolution is giving an unexpected boost to the workhorses of cancer treatment. When paired with angiogenesis inhibitors, radiation and conventional chemotherapies have been shown to exert a cancer-fighting power beyond what they had before. In the latest twist, tumor toxins such as cyclophosphamide and vinblastine are themselves being shown to exhibit hidden antiangiogenic properties. It makes sense, said Tim Browder, HMS instructor in pediatrics at Children's Hospital.
Chemotherapeutic agents kill growing cells.
Also, if you give chemotherapy systemically, that is, through the bloodstream, the first place it's going to see is the endothelial cell before it even gets to the tumor cell. In fact, when Browder administered low doses of cyclophosphamide every six days to mice with drug-resistant tumors, endothelial cells began dying off 12 hours later and continued dying for two days. Tumor cell death did not peak until four days after treatment. By lowering the dose and never stopping the drug, you limit toxicity and you gain a more sustained suppression of cancer cell growth. During a recent interview, he immediately produced a copy of the July 20 report.