Yale Cancer Expert Corrects Misconceptions About Pediatric Cancer
Asher Marks, MD, is the director of pediatric neuro-oncology at Yale Medicine. He started his path to neuro-oncology during his medical residency, when he realized how rewarding it felt to work with not just a patient, but a whole family, during brain tumor treatment. He recently appeared on Yale Cancer Answers to talk about pediatric brain tumors, and common misconceptions about their treatment. Listen to the full episode to learn more about how the field of pediatric neuro-oncology has changed over the course of his career.
When people hear about childhood cancer, what do you think is their biggest misconception?
The biggest misunderstanding is how well our patients do. It tends to be a nonstarter when someone asks you what you do, and your response is pediatric oncology. Their response is usually, “Oh, I’m so sorry”. But for me, it’s an absolute privilege to practice this type of medicine.
I think that the Cinderella story in oncology really often goes back to pediatric leukemia, where in the 1950s and 60s, there was a survival rate of maybe 20%, and often much lower. Now in pediatric leukemia, we’re at a survival rate of 90 to 95%. With leukemia being the most common type of pediatric cancer, and kids doing really well, we have far more successes than failures now. I think that’s probably the biggest misconception.
How common are pediatric cancers in Connecticut?
It’s about 200 to 250 new diagnoses in Connecticut every year. Putting that in perspective, that’s about 3.35% of the overall population. About one in every 285 or one in every 300 children in the U.S. will be diagnosed with cancer before they’re 20. It’s relatively rare, and a large number of those fall into these very treatable groups.
Is it true that pediatric tumors are the hardest pediatric cancer to treat?
I think it depends on which tumors we’re looking at and how we define success. Overall, about 75 to 80% of every brain tumor patient in a pediatric population is surviving at five years. This is a wonderful number. There are certain brain tumors that are truly inoperable and truly have survival levels closer to 0%, unfortunately. They’re not the most common, but they’re out there.
Where we need to be putting our efforts is in ensuring not only that we’re not dealing with mortality, but we’re also diminishing morbidity. And what I mean by that is our patients are not only surviving but thriving. When you have a tumor somewhere else in the body, it can often involve surgery, and the surrounding anatomy might be important and can be moved out of the way. But when you’re operating on the brain, it’s a whole other story. You have to be really careful when you operate on the brain to take the part of the brain that is abnormal and leave everything else as close to intact as possible.
When we talk to our neurosurgeons, they talk about how these surgeries are extremely long. You know, six hours, 12 hours, 18 hours. They’re moving very slowly. They’re working at the vascular level, working on these small vessels around the tumor, and then they’ve got to make the decision while operating how much to take, how much is safe, how much is going to give the best chance of survival.
How has our understanding of children’s brain tumors changed?
When I came out of fellowship, 13-14, years ago, almost every patient was treated with IV chemotherapy. Now when we look at certain tumors, particularly what we call low-grade gliomas, some high-grade gliomas, we look for specific mutations. Often along the MEK-RAS pathway, we look at BRAF mutations, MEK mutations, and we actually have some oral chemotherapies that we use to target these specific mutations.
This means that we can now leave the healthy cells alone, and only the cells that carry these mutations, only the cells that are resulting in growth of the tumor are being affected. It’s become a game changer. We had a clinic, I remember, about six months ago, where me and my fellow neuro-oncologist, Dr. Vidya Puthenpura, were looking at our schedule, and we said, “We’ve got no patients getting IV chemotherapy today. They are all on oral chemotherapy, and they’re all doing great”. That was an amazing feeling.
This Q&A was adapted from Connecticut Public Radio’s “Yale Cancer Answers,” a weekly program that shares information on the latest cancer breakthroughs and treatments through conversations with experts from Yale Cancer Center.
