However, a new therapy tested at Children's Hospital of Philadelphia is giving the young patients a fighting chance.
6-year-old Hayley Kudro is fighting neuroblastoma, a cancer of the nerve tissue.
It can first show up in the stomach, chest, or neck.
"We've done 6 rounds of chemotherapy. She's had a tumor resection where they removed a little over 50% of the tumor. She had a bone marrow transplant which she received her own stem cells, and she's had 4 weeks of radiation therapy," Hayley's mother Karen said.
Despite such aggressive treatment, only about a third of the kids with neuroblastoma survive.
But now, at Children's Hospital, researchers say immunotherapy could improve those odds.
"Really the intent here is to redirect the immune system against the cancer cells so that the immune system of the patient's own body actually attacks and kills the cancer cells," Dr. Stephan Grupp said.
In this approach, specially engineered proteins seek and destroy substances on neuroblastoma cells.
Then they coax the patient's immune cells in to attack.
"So the protein forces the immune attack on the tumor. The protein itself can kill the tumor cells, but the protein also attracts some of the active cells of the immune system to kill the tumor cells as well," Dr. Grupp said.
In their tests, cure rates rose by 20 percent.
"That's what we want. We want the tumor gone, and we don't want it to ever come back," Karen said.
The tests on this new treatment are continuing.