"Basically, 2,000 kids in the United States get diagnosed with brain tumors a year. There's about 20,000 adults that get diagnosed. And so there's a big difference in the numbers even though both are still considered rare tumors in the scheme of things when you look at breast and colon. The majority of the adult tumors are gliomas, malignant gliomas. There is no majority tumor really for pediatric brain tumors. About half of the tumors that are diagnosed are malignant.

"So we narrow down to about 1,000 malignant tumors. Twenty percent of those are what we call magio blastomas. Ten to fifteen percent are brain stem gliomas. Ten to fifteen percent are astrocytomas. So you have very small numbers of a number of different brain tumors. And that's been the problem in trying to study these tumors. And that's why they always get grouped and lumped together when you do a study. So you get a new drug. You get a new cytotoxic drug in the past that's non-specific and hence a dividing cell. And you try to treat these children with that. And sometimes you get a hit and it may respond. And sometimes you don't.

"But what's been happening recently is, number one, realize that the pediatric tumors are different from the adult tumors in many ways. They've started doing genetic and molecular testing on some pediatric tumors and have found some significant differences. So one example is there's a tumor called fibrilary astrocytoma which is a grade two tumors. And it occurs in children and it occurs in adults. But biologically they behave very differently even though they look the same under the microscope. The fibrilary astrocytomas in children rarely will become high grade tumors during childhood years."