A former elementary school classmate of mine died of glioblastoma just this month. I hadn't seen him in decades, but I followed his cancer battle on the CaringBridge website. Although I will forever admire his grace, determination and positive attitude about his condition, when I first heard what he'd been diagnosed with I knew the situation was grim--few glioblastoma patients survive longer than two years after diagnosis.
Ironically, as I was following my friend's battle, I was contacted by radiation oncologist Martin Brown, PhD. Brown taught some of the first cancer biology classes I took as a graduate at Stanford, and he'd had some interesting results while studying mice implanted with human glioblastoma. It seems that the punishing doses of radiation aimed at the cancer also kill the cells of the blood vessels supplying oxygen and nutrients to the tumor. Sounds good, right?
In some ways it is. The primary tumor often shrinks as a result-giving the patient a welcome remission. But most glioblastomas return in short order. It's been a mystery as to how they bounce back so quickly. Now Brown has shown that, when their primary blood vessels are damaged, the tumor turns to a back-up pathway to generate new vessels. Blocking this second vessel-generating process prevented recurrence of the glioblastomas in the mice for the length of the study (100 days). Interestingly, one of the ways in which Brown and his colleagues accomplished this was by administering a small molecule that has already been approved for use in humans for an unrelated condition. Although routine use of this drug, called AMD3100, to treat glioblastoma is far from certain, the investigators are pondering human clinical trials.