Stem Cell Transplant Technique Shows Promise In Fight Against Cancer
The toddler struck a pose, his smile framed by chubby cheeks and curly black hair.
The photograph of Caden Ledbetter, taken last spring, hangs across from his hospital crib as a reminder.
Cancer has taken the 2-year-old's baby fat. His hair. His freedom. At times, his smile.
It might have taken Caden's life, too. But a breakthrough stem cell transplant gives his family hope that the boy in the picture will return.
Stem cells taken from his own umbilical cord at birth were pumped back into his body last month at Medical City Dallas Hospital. Using a patient's own cord blood is uncommon for any illness. The treatment for neuroblastoma, a rare but deadly cancer that attacks the nervous system, is nearly unheard of.
"It's either the second or third time it's ever been done in the world," said Joel Weinthal, Caden's doctor.
Donors usually supply cord blood for transplants, but Caden's parents paid to save his own.
New technique
Experts disagree on the long-term benefits of using a person's own cord blood to treat cancer. Some physicians say the prenatal cells will just turn cancerous again over time.
As a result, parents aren't exactly lining up to store their babies' cord blood as a form of insurance. And the parents who do pay up to US$2,000 for storage and most never need it.
Caden's healthy cells will replace those contaminated by neuroblastoma. The disease had spread to his bones, liver and bone marrow. Weinthal, a pediatric oncologist, says it's the ideal treatment for the Coppell, Texas, boy, who dodges the risk of rejecting someone else's stem cells.
The doctor has hope on his side, if not much research. He points to a successful 1999 transplant involving a 1-year-old girl in Brazil.
John and Lexie Ledbetter, Caden's parents, put their faith in God rather than science.
"The doctors can do the best to heal him," said Lexie Ledbetter, 41. "But when it comes right down to it, you've got nothing but praying that God heals him."
Unused resource
Transplant doctors are turning more often to umbilical cord blood as a rich source of stem cells for patients with cancer, blood and immune system disorders, and dozens of other diseases.
More than 5,500 stem cell transplants used cord blood between 1989 and 2007, research from the American Academy of Pediatrics shows.
The new wave in transplants has given way to more options for storing umbilical cord blood.
Parents can pay to freeze their babies' umbilical cord blood in privately run storage banks. Nationally, less than 1 percent of them do, Weinthal said.
At least 21 states, including Texas, have set up public cord blood banks for donations.
About 7,000 donations have flowed into the Texas Cord Blood Bank in San Antonio since 2004, said Mary Beth Fisk, a bank vice president. "It certainly has grown exponentially," Fisk said. "Most people are very gracious in saying yes."
Pregnant women, meanwhile, have been bombarded with marketing materials from private cord blood banks.
When Ledbetter was pregnant with Caden's older twin brothers five years ago, a hospital pamphlet told her about pre-natal vitamins, baby formula and cord blood banks.
Ledbetter and her husband, John, liked the idea of storing their twins' umbilical cord blood. They didn't like the price tag, especially with a new mortgage and hospital bills on the way.
The couple came back to the idea just before Caden was born in 2005. After some research, they picked a private blood bank in Florida.
Lexie Ledbetter said Caden's umbilical cord blood was an investment for all three of her sons.
"You just never know if somebody's going to need it," she said.
In July, Lexie Ledbetter ran her fingers through her son's curls at naptime and felt a small knot on the top of his head.
She and her husband thought the boy had hit his head, but they took him to the pediatrician anyway.
When X-rays didn't find anything, the pediatrician told Lexie Ledbetter to watch the bump for changes, which could signal a tumor. She did. And it grew.
"My stomach was telling me there's something wrong here," she said. "I was like, 'god, please of all times I want to be so wrong, please let me be wrong about this.' And it wasn't."
"Astronomical" luck
The Ledbetters were sent to Weinthal, who gave the advanced-stage diagnosis. Caden's first round of chemotherapy started on August 2, his second birthday.
Lexie Ledbetter told the doctor that she'd saved the blood from Caden's umbilical cord.
"I was a little shocked and excited," Weinthal said. "The odds of something like this happening is astronomical."
Whether Caden is better off with his own stem cells is a medical question over which experts disagree.
Dr. William Shearer, a pediatrics and immunology professor at Baylor College of Medicine, says most cancers are better treated with stem cells from a donor who isn't likely to develop the disease.
Survival rates for those patients range from 40 percent to 90 percent, he said.
Shearer discourages parents from saving the blood from their babies' umbilical cords, an expensive investment that he says rarely pays off.
"The most useful thing to do is to make your baby's placental stem cells available to the general public because somebody somewhere in the world will need them desperately," he said.
Weinthal's goal is to cure Caden's cancer. If that doesn't happen, the boy's mother hopes it at least buys him more time.
"He's coming around to the age where enough research is being done that if his tumors would come back at some point in time they could do something about it," she said.
Last month, stem cells from less than an ounce of Caden's umbilical cord blood flowed into his body intravenously. The transplant took about five minutes.
The stem cells embed themselves in bone marrow. Over time, they grow, divide and branch off into various blood cells.
While his immune system rebuilds, Caden will be secluded in his room at Medical City hospital's stem cell unit for up to a month.
His new home away from home has its own air filtration system and water supply, as well as heavy steel doors and warning signs to keep out most visitors.
Caden's mother, a small woman with warm brown eyes, sleeps in a hospital bed next to her son's crib.
She covered the room's walls with pictures of Curious George and Winnie the Pooh.
There are photographs of Caden's older brothers, Joshua and Zachary, right next to pictures of a stronger, smiling Caden.
Neuroblastoma is one of the toughest pediatric cancers because it comes back about half the time, Weinthal said.
Statistically, Caden's opponent isn't known to back down.
But neither is Caden, whose name means "warrior."