Robert Lopez, AP

Four-year-old Khalid Amos lifts his shirt up and reveals a faint scar on his chest. “That's my port,” he says. “That's where they put the medicine in, take blood out.” Khalid was diagnosed two years ago with neuroblastoma, a tumor of the sympathetic nervous system, which controls the body's fight or flight responses.

The cancer now is in remission, and he remains a playful, if shy, little boy. He also has become a public face for his condition. Khalid was named this year as one of St. Baldrick's Foundation's five International Child Ambassadors. The Monrovia, CA-based organization is best known for its head-shaving events, where volunteers cut off all their hair to draw attention to and raise money for childhood cancer research. Khalid's mother, Danielle Cureton, will lose her locks in September as part of a campaign titled 46 Mommas Shave for the Brave.

Cureton was about six months pregnant with her daughter Alina when she noticed that Khalid wasn't eating much. “He was also just laying around the house,” she said. “He would dance all the time, was always singing. But then all he wanted to do was lay down. He didn't want to run around or do anything else. And he wouldn't eat, even if we gave him his favorite foods.”

She took Khalid to the doctor, who ran some blood tests but couldn't find anything wrong. They then went to Brenner Children's Hospital to get some X-rays taken. “They could tell there was a blockage, but couldn't tell it was a tumor,” Cureton said. “And so they sent us home and six days later he started looking even skinnier, even worse.”

Khalid returned to the hospital and had a CT scan. The doctor couldn't tell for sure, but thought it might have been neuroblastoma. Two days later a biopsy was performed that confirmed it. Neuroblastoma occurs mainly in children younger than 10. About 650 new cases appear in the United States each year, and it's the most common solid, non-brain-tumor in children.

“One of the problems with neuroblastoma is that it tends to grow in the belly, where there's a lot of room to grow,” said Michael Armstrong, a medical instructor and pediatric oncologist at Duke University. “So we might not find it until late in the disease. Some kids will complain of belly pain. Or the parents might be giving the child a bath and feel a mass in the abdomen. They (the tumors) will occasionally grow in the chest and so there will be some respiratory complaints, such as a cold that won't go away.”

Lower-risk tumors can just be removed through surgery, Armstrong said, with a little bit of chemotherapy afterward to get rid of any tumor cells left behind that couldn't be taken care of otherwise. Higher-risk tumors, however, might need intensive chemotherapy, radiation therapy, bone-marrow transplants and maintenance therapy.

Khalid had several tumors, the biggest of which was on his adrenal gland and wrapped around an artery that supplied blood to his left kidney. He was started on chemotherapy the day after the biopsy results came back, and spent the next three weeks at Brenner. The family also had to make occasional trips to New York for antibody therapy.

Eventually a tube was inserted in his chest so the doctors wouldn't have to poke him constantly with needles. He also ended up losing sight in his right eye permanently. Altogether, he spent about a year getting treatment, which included 14 cycles of radiation, seven blood transfusions, six rounds of chemotherapy, four bone-marrow aspirations, three platelet transfusions, three minor surgeries and one major surgery.

“It was scary,” Cureton said. “I just felt so bad because it was something we didn't know if we could fix. If he had gotten a broken arm, we knew we could fix that. But with this, you just have to go by what the doctors tell you and trust that they will be able to fix it.”

His parents managed to find a sitter for the nights they both had to be away and arranged their work schedules such that one parent could be home while the other one traveled with Khalid when he had to go to New York. But the illness also put a strain on the rest of the family.

“For awhile I really didn't get to see the kids that much,” Cureton said. “It got them off their rhythm. There were a lot of things that we needed to try to do with the kids but didn't have much time for. We had some issues with grades. But they did step up, do chores around the house.”

Khalid does not seem to remember much about the experience, other than his belly hurt and he got to eat a lot of crackers, chips and juice afterward. He has had a few relapses, Cureton said, but the results from his latest biopsy were good. As an ambassador, he will appear on posters, annual reports and promotional materials for the organization.

“It just kind of puts the face on what the cause is,” Cureton said. “Khalid is a success story. It shows that children are surviving.” And she said she's not nervous about going bald herself in September for the St. Baldrick's fundraiser. “I can't imagine going through half of what he did,” she said. “If all I have to do is get rid of my hair, I'll be fine.”