Survivors of paediatric cancer are at greater risk for high cholesterol, diabetes and high blood pressure, all of which predispose them to heart disease. These risk factors for heart disease are being found at an earlier age than in the general population, according to research published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.
Lillian R. Meacham, MD, medical director of the Cancer Survivor Program and professor of paediatrics at Emory University, extracted data from the Childhood Cancer Survivor Study, which included 8,599 cancer survivors and 2,936 of their siblings.
"In data previously published from the Childhood Cancer Survivor Study, paediatric cancer survivors were found to be at almost 10-fold greater risk for cardiovascular disease than their non-survivor counterparts," said Meacham. "In this study we identified whether the predisposing risk factors for cardiovascular disease – obesity, hypertension, hyperlipidaemia and diabetes – were present at higher rates compared to siblings. If the risk factors could be recognised and treated early it is hoped some of the long-term cardiac side effects could be averted."
Meacham found that cancer survivors were nearly twice as likely as their siblings to take medication for high blood pressure, 60 percent more likely to take cholesterol medication and 70 percent more likely to have diabetes.
Radiation treatment may be playing a role in the development of risk factors for cardiovascular disease, Meacham said. Total body irradiation was linked with a 5.5-fold increased risk and chest and abdomen radiation a 2.2-fold increased risk of cardiovascular risk factor clustering, which when present is associated with subsequent cardiovascular disease.
"Mechanistically, we are not yet sure why this is, but the association is definitely there," said Meacham.
Researchers examined the presence of cardiovascular risk factors and found that physical inactivity among cancer survivors was linked with a 70 percent increased risk for cardiovascular risk factor clustering. Older age at the time of the study was linked to an 8.2-fold increased risk for cardiovascular risk factor clustering among survivors compared with children who had never had cancer.
"These risk factors are manifesting at about age 32, which is much younger than a non-cancer survivor would exhibit signs of cardiovascular risk factors," said Meacham. "Some have suggested that when you are a cancer survivor there are parts of you that wear out early, so we need to be vigilant about our follow-up of these patients in order to find these late effects early and intervene."
(Source: American Association for Cancer Research: Cancer Epidemiology, Biomarkers & Prevention: January 2010)