At only 5 years old, Heaven Sanchez received radiation, chemotherapy and a transplant of her own stem cells after surgery to remove a brain tumor. Now 9, she has cataracts in both eyes and an underactive thyroid, complications of the powerful treatment regimen that left her cancer-free.
“The doctors told us what the complications might be,” says Heaven’s mother, Stephanie Sanchez of San Antonio. “At the time, the only thing I was thinking was she has to get better. And we have to do whatever we can.”
Cancer survivors, young and old, confront a variety of health problems after stem cell transplantation, according to a growing number of studies. The reason: collateral damage from therapies used to kill cancer. High amounts of radiation and chemotherapy used before stem cell transplantation, and in some cases, in between multiple transplantations, can destroy the cancer with the potential consequence of bodily harm. Chemotherapy and radiation, for example, can cause congestive heart failure and new, or secondary, cancers.
Leukemia and lymphoma survivors at least 10 years out from transplantation are at higher risk for heart disease, blindness, osteoporosis, new cancers and other post-transplantation complications compared with their siblings, according to a study presented at the American Society of Hematology (ASH) annual meeting this past December. The study also included survivors of aplastic anemia and other conditions.
After a 15-year follow-up, researchers found 74 percent of survivors had developed at least one chronic health condition compared with 29 percent of siblings. One in four survivors developed a severe or life-threatening condition compared with 8 percent of siblings.
Long-term health problems can also result from steroids used to treat graft-versus-host disease, a possible side effect of allogeneic transplantation in which the donor stem cells see the patient’s body as foreign and launch an immune system attack. Osteoporosis, for example, is a possible by-product of steroid therapy in both men and women.
Yet patients aren’t being regularly told about the risk of health complications later on, says Smita Bhatia, MD, director of the Center for Cancer Survivorship and BMT (Bone Marrow Transplant) Long-Term Follow-up Program at City of Hope in Duarte, Calif. “That’s because the data are just emerging on these long-term morbidities, so it will take three to four years before those discussions become incorporated into the standard practice,” says Bhatia, senior author of the survivor study presented at the ASH meeting.
Long-term survivors are also at higher risk for a psychological health condition called somatic distress, according to Bhatia’s study. Somatic distress occurs when there’s no medical underlying cause for a particular symptom, yet a survivor experiences it. It may be in the form of abdominal pain or shortness of breath. “There really isn’t much of a clue as to why that is happening,” Bhatia says.In Heaven Sanchez’s case, doctors know what caused her eye cloudiness: radiation she received to the brain and spinal cord. Her vision started to change within two months after she finished treatment. More than three years later, her vision has worsened to the point where she can barely see a few feet in front of her.