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Promise and Progress - A Fighting Chance

Faces of Childhood Cancer

A Fighting Chance

Date: June 1, 2004

Fifteen-year-old Chris Petty has Hodgkin’s disease, one of the so-called good cancers. His disease is curable 90 percent of the time. Pretty good odds unless, like Chris, you happen to be one of the 10 percent whose cancer does not respond to standard therapy. But, with a dedicated team of researchers and clinicians working together to develop new strategies to combat his relentless disease, Chris has a fighting chance.

 Chris Petty was just 12 years old when his battle began. The night sweats, fever and fatigue that his doctor thought was mononucleosis turned out to be Hodgkin’s disease, an aggressive cancer of the lymphatic system.

Hodgkin’s disease is considered one of the great victories in the war against cancer because chemotherapy and radiation therapy cure the vast majority of those diagnosed. This gave Chris’ father, a Navy officer, and his mother, a nurse, some comfort.

It was expected to be a brief detour in Chris’ life.  There is no question it would be tough, but after chemotherapy and radiation, Chris was supposed to be cured.  At least that’s what the Petty family learned happens in most cases of Hodgkin’s disease.  But, Chris’ cancer was different.  “It’s called mixed cellularity Hodgkin’s disease, and his was diagnosed at a later stage and was very aggressive,” says Meghan Higman, the Kimmel Cancer Center oncologist now treating him. “We know it puts patients at higher risk of recurrence.” 

Not recognizing this subtle difference, the military doctors near the Virginia naval base where his father was stationed treated Chris with standard therapy.  And for about five months everything looked good. Chris thought his battle with Hodgkin’s disease was over.  Then the night sweats and fevers returned. Chris’ Hodgkin’s disease was back. The Petty family was learning that Chris’ cancer was not a textbook case, and their brief detour would likely be a long and complicated journey.

What Now?

The treatment that offered Chris his best chance of survival was an autologous bone marrow stem cell transplant. This therapy allows doctors to give very high doses of chemotherapy that destroys not only cancer cells but healthy bone marrow cells as well. The lost healthy cells are replaced with an infusion of stem cells previously collected from the patient. These stem cells would automatically travel deep within Chris’ bones and repopulate the vital blood and immune cells destroyed by chemotherapy.  Stem cell transplant is an intensive and complicated therapy that requires expertise available only at the nation’s leading medical centers.  Chris’ family was now living in Maryland, so Chris went to Johns Hopkins.

Chris did not receive a typical transplant but rather a novel approach developed by Allen Chen, director of the Kimmel Cancer Center’s pediatric bone marrow transplant program, which included immune-boosting shots that would hopefully trigger his immune system to clean up any remaining cancer cells not destroyed by chemotherapy.

 Soon into the therapy, however, there were already red flags.  “Chris was tolerating the chemotherapy extremely well, perhaps too well. This may have been an indication that the anticancer drugs were being metabolized differently,” says Higman. Just 35 days after his transplant, her suspicions that the therapy was not working were confirmed when Chris’ Hodgkin’s disease returned yet again.

A Third and Unusual Attempt

“After two relapses, I was faced with having to tell his family there was no chance for survival,” says Higman. It is not an outcome Kimmel Cancer Center pediatric oncologists easily accept. Higman was not willing to give up, so she discussed Chris’ case with Chen and another Hopkins colleague, Cindy Schwartz, head of the Hodgkin’s Disease National Collaborative Study Group.  She recommended another transplant, this time using donor stem cells.  But, Chris would have to recover from his first transplant without his Hodgkin’s disease progressing before a second transplant could even be considered.  Even then, the therapy was a long shot. 

Bone marrow donors are chosen based on a test for human leukocyte antigen (HLA). HLA is part of the biological process that allows each individual’s immune cells to differentiate between its own cells and the cells of other people or foreign organisms. The catch is that the immune system of the donor must match the immune system of the recipient; otherwise the immune cells in the donated marrow do not recognize their new host and launch a deadly attack against the patients’ tissues and organs. The best chance of a match usually comes from siblings and parents. In Chris’ case, his sister and parents were not a match. Those who don’t have a match within their family usually turn to the unrelated bone marrow donor registry, a listing of volunteers willing to donate their bone marrow. For Chris, part Native American, this would not be an option either because unique genetic components specific to his heritage would be difficult to match outside of his family. 

The solution to this problem came from Ephraim Fuchs, yet another Kimmel Cancer Center physician-scientist. Chris would be enrolled in a new clinical trial that involves using a family donor, in this case Chris’ mother. She partially matched her son’s immune HLA type. Usually, only siblings can be identical matches, but this study would use a half-identical, or haploidentical donor. Haplotypes, or the genetic composition of any individual, is inherited equally from each parent, so a parent is always a half-identical match to his or her child. This therapy also called for less chemotherapy, and because Chris had already undergone such intensive treatment, his doctors believed this milder approach would be more tolerable.

Never Give Up the Fight

At 15, Chris was old enough to understand what was happening but much too young to have to face his own mortality. A bright kid who enjoyed reading video game magazines and writing novels and short stories, Chris was now reading medical journals and trying to rewrite his own future. He knew the odds were not in his favor. But this had been his life for the last three years. He had already beaten the odds by making it this far, and he was not ready to give up the fight—and neither were his doctors or parents.

This time, the transplant appeared to be working. Because his mother was only a half match to his immune system, Higman placed Chris on immunosuppressants to keep his new immune system, contained within his new donor bone marrow, in check. Some immune reaction is actually deemed beneficial and can help wipe out any remaining tumor cells. Too much, however, can cause life-threatening damage to major organs. The challenge for doctors is to get just the right balance.

Chris’ bone marrow cells returned, and tests showed they were his mother’s cells, so from that perspective, the transplant had been a success. However, tests showed some cancer cells had survived as well. Chris’ kidneys were already showing damage from the Hodgkin’s disease and its treatment, and he had had as much radiation therapy as he could safely receive, so further treatment options were limited. The team decided to stop all immunosuppressants in the hopes that, unbridled, his new immune system would clean up the cancer cells.

For the time being, this approach appears to be working. 

Chris has good days and bad days. It is the quiet moments that he finds the most difficult. He has been troubled by nightmares. He worries about dying. Not the process itself, but just the idea of being gone from this world and not being remembered. He has not had a chance to realize his dreams and goals—to make his mark on the world. For Chris, this is what he finds most troubling but it is also what gives him his relentless will to fight the cancer.  Higman is with him all the way. 

“In pediatrics, kids defy the odds all of the time. That’s why we don’t ever give up. If anyone can do it, Chris can,” she says. “We’ll keep going and keep trying, and he could be looking back on this at 60 years old, telling this story to his grandchildren.”

“Every patient,” she says, “deserves a fighting chance. We owe him that much.”