It seems that a lot of people would be surprised to learn pediatric brain tumors are the leading cause of death for children diagnosed with cancer.
The fact is, more kids die from brain tumors than any other type of pediatric tumor because we don’t have great treatments. If we compare it with leukemia, leukemia is four times more common than pediatric brain tumors, but we’re curing 90% or more of those kids because researchers and clinicians have done such outstanding work for decades and because the public and our research institutions have supported it. Now we’re really catching up in understanding how brain tumors work and developing treatments that can benefit patients.
What innovations in pediatric brain tumor research are happening in the CU Cancer Center?
We have one of the largest groups of pediatric brain tumor researchers in the country; it’s one of the hidden secrets on campus. Our team is pretty amazing. Currently on the research side, there are seven principal investigators who run research labs focused on pediatric brain tumors, so that’s approximately 40 individuals, including graduate students and research assistants. We work as a cohesive group sharing ideas, resources, and expertise to drive research from basic genetic mechanisms to testing new drug therapy. Our work has been supported by the Morgan Adams Foundation for over two decades, which has allowed us to pursue many high-risk, high-reward studies. This and other philanthropic support have allowed our team to obtain significant national funding to further pursue research in childhood brain tumors. For example, we currently have five National Institutes of Health R01 grants and three Department of Defense grants.
One unique thing that we’ve done is create a patient tumor bank with over 1,400 patient tumor samples that we’ve collected. We’ve done lots of genomics on these samples, published a lot of papers, and we’ve also been doing a lot of single-cell sequencing. We’re making all that data publicly available through an online portal, and we’re working on a second portal for all the genomic data, so these will be available to anyone in the world. We also have mouse models of every pediatric brain tumor, and we were the first in the world to generate some of those.
What’s happening in clinical research for pediatric brain tumors?
A lot of the work we’ve done in the lab over the past seven years or so has actually translated into clinical trials. Currently we have three open trials that came directly out of work done in our laboratories, and two additional trials in various stages of the federal approval process that we hope to open in the next few months. We’re one of 17 institutions around the U.S. that are part of a pediatric brain tumor consortium funded by the NIH for phase 1 trials. Overall, through this and other partnerships we have 17 experimental clinical trials to offer patients with brain tumors.
One of the things that makes our group reasonably unique is our focus on translatability. We have infrastructure in place and intellectual interest focused on how we can take this from the lab to our patients now. We study a lot of basic mechanisms and ask, “What in there is targetable that already has agents in adult cancers?” Historically, drug companies have been more willing to treat 50,000 adults with colon cancer, for example, than 500 kids with brain tumors. If we can identify mechanisms that are applicable to adults, it’s a lot easier to get that into kids.
A significant amount of cancer research involves immunotherapies; is that also true in pediatric brain tumor research?
On immunotherapies, we have several big projects. One of them, research being led by Nick Foreman, MD, is looking at two subsets of tumors: those that don’t relapse and those that relapse very quickly. Among the ones that relapse very quickly, the macrophage infiltration is very different, so this research is working to understand what those mechanisms are and what suppresses response to therapy.
We also have Sujatha Venkataraman, PhD, who’s looking at the immune mechanisms targeting diffuse intrinsic pontine glioma (DIPG). It’s the one tumor in pediatrics for which there is no therapy currently, so every patient with DIPG will die within 12 months and we’ve made no improvement over the last four decades. We discovered, when Sujatha was working with me as a research associate, a protein on DIPGs that could be targeted with CAR T cells. Sujatha is working to develop those CAR T cells toward DIPG and has done some beautiful work. We have models where we can deliver CAR T cells directly to the brain through a pump system or direct infusion.
Nathan Dahl, MD, who trained with us, is also doing really great work in understanding how DIPG resists radiation and understanding what makes cells more sensitive to radiation.
In a lot of this research, we’re learning how the mechanisms within pediatric brain tumors have applications for other pediatric cancers. We’ve learned that antibodies for DIPG also target Ewing sarcoma, for example. This is really important for me as a physician who sees patients, because every time I have to sit in a room with a young patient who has a DIPG diagnosis and say to their parents, “You have maybe 11 months; go maximize it,” it’s why I and everybody in the labs work so hard.
How does the CU Cancer Center’s multidisciplinary approach to treatment affect pediatric brain tumor patients?
If you have a brain tumor, it’s likely you’re going to have issues with coordination, with speech, swallowing, vision, your hormonal function. Your pituitary gets impacted, your thyroid, your cortisol levels. We have patients who develop obesity because their hormonal control has completely gone wacky. All of these things are part and parcel of what we treat, and there are great teams throughout campus who we partner with to give the best care to our patients.
I am particularly proud of how we have developed a team across multiple specialties including pediatric neurooncology, neurosurgery, radiation oncology, radiology, social work, ophthalmology, rehabilitation medicine, and endocrinology to treat our patients in a comprehensive manner. The research we do in the lab is also based strongly on teamwork and collaboration. As cliched as it may sound, we have truly developed a culture of working together at all levels to ensure that the present and future for kids with brain tumors is better than the past.