An increase in duration of infusion of each dose to six hours or longer may reduce risk for heart complications associated with anthracycline drugs, according to an article in Issue 4 (2006) of the Cochrane Database of Systematic Reviews.

Anthracycline therapy with drugs such as daunorubicin and doxorubicin can be very successful at controlling cancer, but heart damage caused by anthracycline treatment “is a considerable and serious problem,” said Elvira van Dalen, MD, of the Emma Children’s Hospital in the Netherlands.

In five studies involving 557 patients, the longer treatment cut the risk of heart failure in adult patients by nearly 75 percent compared with risk in patients who received shorter treatments.

The authors speculated that the prolonged dose duration of six hours or more “might be justified” if a patient is at high risk of heart damage or needs a high cumulative dose of chemotherapy.

In some of the studies, the prolonged dose also reduced the risk of less severe problems such as weakened ventricular function. Patients had the same chance of survival and tumor shrinkage regardless of drug infusion duration.

“It should be emphasized that the majority of the patients included in these studies were adults with advanced solid tumors,” van Dalen and colleagues said, noting that there are few good studies about the length of anthracycline treatment in children.

Among the children in the study, there was no difference in heart damage between the long and short treatments “and no information on survival and tumor shrinkage was available,” van Dalen said.

Recent studies have shown that the toxic heart effects of anthracycline therapy can have lasting effects on children’s health. Dr. Stephen Lipshulz, a pediatric cancer specialist at the University of Miami, said childhood cancer survivors “may be at significant risk of serious cardiovascular problems at a much younger age," than researchers believed a few years ago.

Lipshulz’s work suggests many childhood cancer survivors develop enlarged hearts and premature atherosclerosis, due at least in part to their chemotherapy. “It’s alarming that we’ve found such dramatic heart damage and blood vessel risk in some survivors who are just 10 or 15 years from treatment,” he said.