Costly Cancer Treatment Aimed at Protecting Kids' Hearts Doesn't Work
Study findings could cut hospital stays, reduce patient stress
May 18, 2002
A new study refutes a long-held but unproven theory that children suffering from acute lymphoblastic leukemia might suffer less heart damage if treated with longer-lasting infusions of chemotherapy.
Each of these longer-lasting treatments requires a child to spend at least two days in the hospital, causing tremendous anxiety and inconvenience, and costing millions in the U.S. each year. Details of the study by physicians at 10 hospitals throughout the United States and Canada are in the March 15 issue of the Journal of Clinical Oncology.
On average, 7,000 U.S. children are diagnosed with cancer each year. For the thousands who receive chemotherapy, one of the possible side effects is heart damage. For years, physicians believed that giving children who have acute lymphoblastic leukemia - the most common type of cancer in young children - a lower peak dose of the widely used chemotherapy drug doxorubicin might prevent cardiomyopathy, a weakening of the heart muscle often caused by the treatment.
There was little data, however to back up this claim. Prior studies examining the protective effects of continuous doxorubicin in adults didn't provide long-term heart data.
"In theory, using this treatment method for children sounded great," says the study's lead author, Steven Lipshultz, M.D., chief of pediatric cardiology at the University of Rochester Medical Center's Strong Children's Hospital and a professor of oncology at the University's James P. Wilmot Cancer Center. "It's been written into national and international treatment protocols to protect the heart."
The study involved 240 children who had high-risk, acute lymphoblastic leukemia. Physicians compared cardiac outcomes of children receiving bolus treatments - a injection of doxorubin done within one hour - to those who received the medication by continuous infusion during a 48-hour span, which Lipshultz describes as "a trickle at a time." Physicians obtained echocardiograms to measure heart function before doxorubicin treatment and repeated those tests 18 months later.
Continuous doxorubicin infusion for children offered no advantage over bolus infusion in terms of avoiding a weakening of the heart muscle. Lipshultz's team found that both types of infusion were associated with progressive heart disease. "We don't think continuous infusion for children should be used if the primary reason is to reduce possible heart damage," Lipshultz says. "We saw no sign that damage to the heart was minimized in anyway."
Lipshultz, one of the world's leading pediatric cardiology researchers, has been studying and publishing about the long-term effects of chemotherapy on children for 20 years. "This was the first randomized, controlled, multi-center study created specifically to learn how we can protect children's hearts from chemotherapy," he says. "What we found was that continuous infusion didn't offer the heart protection that many in the medical community have assumed it did for more than 15 years."
There might be significant benefits to reverting to the bolus form of infusion. "Although we didn't look at these factors in any formal way, continuous infusion appears to be associated with increased hospitalizations, higher medical costs, and an increased stress on these children," Lipshultz says. "The effects of increased hospitalization on the patient's quality of life and psychological well-being are important to consider."
Financially, the savings from eliminating continuous treatment would be substantial. Lipshultz says there are about 7,000 new cases of childhood cancer each year, about half treated with doxorubicin-type drugs, which are used to treat many forms of cancer. In the study, children receiving continuous infusions required at least 24 days in the hospital that children receiving the shorter infusions did not need. At an average cost of $2,000 per day for hospitalization, the tab for continuous-infusion treatment was $48,000 for each child.
Lipshultz was joined on this study by colleagues throughout the United States and Canada, including Barbara Asselin, M.D. Asselin is an oncologist at Strong Children's Hospital and the James P. Wilmot Cancer Center. The study was funded by a grant from the National Institutes of Health.