Diffuse Intrinsic Pontine Glioma (DIPG)

Understanding what Diffuse Intrinsic Pontine Glioma (DIPG) means will help you understand just why this cancer is so hard to beat.

• Diffuse – Threaded through healthy brain tissue, a DIPG tumor is not a solid mass. It can’t simply be removed with surgery.
• Intrinsic – It’s due to causes within the brain itself. Some studies suggest DIPG tumors start in childhood because kids’ brains are developing so much, so quickly. There’s no research linking DIPG to genetic or environmental causes.
• Pontine – The tumor grows in the pons, the part of the brainstem that puts breathing, swallowing, and other basic bodily functions on autopilot. It can also, less frequently, arise in other parts of the brainstem or extend into other areas. The location makes the tumors all the more debilitating and treatment all the more risky.
• Glioma – The tumor starts in glial cells, the white matter “glue” that supports and insulates neurons throughout the brain.

Even as outcomes for children with other types of cancer have vastly improved, long-term survival rates for DIPG have been stalled  for more than 50 years. Most DIPG patients die within a year of their diagnosis. Less than 10 percent see two birthdays beyond their diagnosis. In the interim, DIPG patients suffer debilitating side effects as the growing tumor presses on the brainstem and makes seeing, walking, and even breathing increasingly difficult. Yet, precisely because it’s one of the most challenging and lethal cancers, the Children’s team is committed to finding new, more effective treatments for DIPG. We also believe that if we conquer DIPG, we’ll unlock cures for many other types of cancer in the process.

Though children of all ages and even a few adults have been diagnosed with DIPG, most new cases are in children four to ten years old. Some research suggests this is because of rapid brain development in those early elementary years. Symptoms first appear when the tumor puts pressure on nerves in the brainstem that control facial, eye, and muscle movement. Parents might first notice that their child is suddenly clumsy, has developed a “lazy eye," or has facial weakness. As the DIPG tumor grows, most patients suffer some combination of:

• Problems seeing, such as double vision, drooping eyes, or a “lazy eye”
• Drooping on one side of the face
• Trouble with movement, particularly on one side
• Difficulty talking, chewing, or swallowing
• Hearing problems, including sudden deafness
• Headaches
• Nausea and vomiting caused by brain swelling

As with many neurological symptoms, an MRI is the best source to create a detailed image of the brain. If the scan shows a tumor in the pons, its infiltration of healthy tissue and undefined shape will suggest it’s a DIPG brain tumor. Until just a few years ago, doctors relied solely on the child’s symptoms and an MRI to diagnose DIPG. The risk of damaging the brainstem was just too high to do a biopsy of the tumor. However, as our technology gets more and more precise, researchers have determined we can safely biopsy DIPG brain tumors.

This important advance also allows us to see the child’s DIPG brain tumor at the genetic level. During the biopsy, a surgeon makes a small hole in the skull and uses a needle to extract a tiny piece of the tumor. The tissue sample can then be tested to determine the type of tumor and its genetic make-up, including mutations. As our research progresses, we hope to be able to target treatments specifically to each tumor’s genomic profile.

DIPG is a neurologically devastating, and in most children, lethal pediatric cancer that develops in the structural tissue of the brainstem, without truly effective therapy. There are more than 300 cases in the U.S. each year, but its relative rarity actually makes fighting DIPG more challenging. 

Surgical removal, also called resection, is not currently an option for these infiltrative tumors. And we have yet to find any chemotherapy drugs effective against DIPG. However, radiation therapy can often kill some of the cancer cells, relieving pressure on the brainstem and some of the child’s symptoms as a result. About 75-85 percent of DIPG patients respond to radiation, improving their quality of life and beating back the cancer in the short term.

Children’s National is one of the few hospitals in the nation that conducts brainstem biopsies for DIPG  that can guide in identifying a course of treatment personalized to each child. Genomics analyses are run to better understand the biology of that specific tumor. Within three weeks, our team of specialists reviews the results and patients with DIPG are placed on therapy that best meets their individual need.