A protective drug called dexrazoxane significantly reduces heart damage in childhood cancer survivors, a large long-term study has found.

The study followed nearly 900 childhood cancer survivors into young adulthood. About 200 were tracked for more than 15 years after treatment. The results were published in the Journal of Clinical Oncology.

Researchers focused on children treated with doxorubicin, a chemotherapy drug, for leukemia, lymphoma and sarcoma. Half received dexrazoxane before each dose of the drug.

Years later, survivors who received dexrazoxane had healthier hearts on echocardiogram tests. Many were classified as moderate rather than high risk of heart damage.

The lead author, Erin Mobley of the University of Florida, said the finding could reduce how often survivors need heart screening as they age. The drug was first approved for adult patients and is now commonly given to children.

More than 80 percent of children diagnosed with cancer now survive at least five years. The study was supported by the US National Institutes of Health.