CHICAGO Children who survive cancer while they are young are five to 10 times more likely than their healthy siblings to develop heart disease, U.S. researchers said on Thursday.
The finding comes from a study of more than 14,000 survivors of childhood cancers, and suggests that cancer survivors and their doctors need to be vigilant about heart risks.
"This study clearly shows for children, and particularly children treated with radiation therapy to the chest or certain drugs that are particularly toxic to the heart, there are significant risks of cardiovascular disease at a far younger-than-expected age," said Dr. Richard Schilsky of the University of Chicago.
The preliminary results were released ahead of a meeting later this month of the American Society of Clinical Oncology.
Schilsky, who is president-elect of ASCO, said the study highlights the challenges faced by cancer survivors, who have to live with the health consequences of having had cancer and having been treated for cancer.
Dr. Daniel Mulrooney of the University of Minnesota and colleagues conducted the study, which looked at 14,358 survivors of childhood leukemia, central nervous system tumors, Hodgkin's and non-Hodgkin's lymphoma, kidney tumors, bone cancers, neuroblastoma and soft-tissue sarcoma between 1970 and 1986.
They compared these to 3,899 of their siblings. Cancer survivors on average were 7 years old at diagnosis and 27 at follow up.
The cancer survivors were 10 times more likely to have clogged arteries, 5.7 times more likely to have heart failure, 4.9 times more likely to have heart attacks, 6.3 times more likely to have pericardial disease -- affecting the sac surrounding the heart -- and 4.8 times more likely to have diseased heart valves compared with their siblings.
"We found 5-year survivors of childhood and adolescent cancers are at an elevated risk for early cardiovascular disease," Mulrooney told reporters in a telephone briefing.
They also found the risks were two to five times greater in people who had been treated with chest radiation and chemotherapy from the anthracycline class of drugs, such as doxorubicin, compared to survivors who did not have those treatments.
Mulrooney said there are about 270,000 childhood cancer survivors in the United States, or about 1 in every 900 young adults. He said the findings may lead to better cancer treatments that protect the heart.
"We still use radiation therapy," he said, but newer radiation treatments are more targeted, and he hopes they will have less impact on the heart.
Schilsky said other studies have found long-term cancer survivors are at greater risk of premature osteoporosis, infertility, thyroid problems, anxiety and depression and the risk of another cancer.
"It becomes incumbent on the patient and the primary care physician to be aware of their cancer history and the potential consequences of their treatment," Schilsky said.
(Editing by Maggie Fox)