Survivors of Childhood Cancers at Increased Risk of Heart Disease
The treatments required to turn childhood cancer patients into survivors often leave them predisposed to future health issues: new cancers, infertility, cataracts, etc. A new study reveals childhood cancer survivors are at increased risk of heart disease.
Lillian R. Meacham, MD, medical director of the Cancer Survivor Program and professor of pediatrics at Emory University, in Atlanta, Georgia, and colleagues used data from the Childhood Cancer Survivor Study (CCSS) to look at the possible risk of heart disease in childhood cancer survivors. They found the risk for cardiovascular disease was approximately 10 times higher among survivors than among their siblings.
The new research published in the January issue of Cancer Epidemiology, Biomarkers & Prevention is part of a growing body of evidence that indicates that childhood cancer survivors are at higher risk of developing metabolic syndrome than the general population.
The CCSS is a multi-institutional study of individuals who survived 5 years after a childhood cancer that was diagnosed from 1970 to 1986. Meacham and colleagues analyzed the data on 8599 of the cancer survivors and 2936 of their siblings who were evaluated for a body mass index of 30 kg/m2 or more, use of medications for the treatment of hypertension, dyslipidemia, and impaired glucose metabolism was also evaluated.
The authors defined Cardiovascular Risk Factor Cluster (CVRFC) as having at least 3 of the following 4 risk factors: obesity, hypertension, dyslipidemia, and diabetes mellitus or impaired glucose tolerance. The CVRFC was used as a substitute for metabolic syndrome,
The risk for developing these cardiovascular risk factors was associated with older age, certain kinds of radiation exposure and physical inactivity.
Exposure to total-body irradiation or abdominal plus chest radiation and a sedentary lifestyle among survivors of childhood cancer are associated with the development of risk factors that can predispose them to metabolic syndrome and subsequent cardiovascular disease, according to
The researchers found no difference in prevalence of obesity between childhood cancer survivors and siblings (20.6% for survivors vs 20.8% for their siblings). After adjustment for age, ethnicity and sex, the researchers reported that compared with siblings, survivors were 1.9 times more likely to be taking medications for hypertension, 1.6 times more likely to be taking medications for dyslipidemia and 1.7 times more likely to be taking medication for diabetes.
More than half of the survivors (59.2%) received radiation as part of their initial cancer therapy, 33.5% received 100 mg/m2 or more of anthracyclines, and 4.7% were treated with platinum therapy. These treatment modalities affected the risk for survivors.
Exposure to more than 100 mL/m2 of an anthracycline was associated with a 50% increase in the odds of hypertension, while those who received more than 300 mg/m2 were less likely to be obese.
Radiation treatment increased the risk of obesity, hypertension, dyslipidemia, and diabetes. Survivors who received cranial radiation were more likely to be obese than those who did not receive radiation. Survivors who received either abdomen or chest radiation or who were currently receiving steroid therapy showed increased risk for hypertension. Survivors who had total-body irradiation were associated with treatment for dyslipidemia and/or diabetes.
"In light of the high prevalence of chronic health conditions, including cardiac disease and associated increased rates of death, it behooves all healthcare providers to be proactive in the early recognition and treatment of cardiovascular risk factors in this population," the authors conclude.
Cardiovascular Risk Factors in Adult Survivors of Pediatric Cancer—A Report from the Childhood Cancer Survivor Study; Cancer Epidemiol Biomarkers Prev. 2010;19:170-181; Meacham L.
Study links cancer therapies and risks of late ocular complications in children; Pediatr Blood Cancer. 2010;54(1):103-109.