Preventable risk factors threaten heart health of childhood cancer survivors
Risk factors associated with lifestyle, particularly hypertension, dramatically increase the likelihood of childhood cancer survivors developing serious heart problems as adults, according to a newly reported national study.
Nationwide, there are an estimated 395,000 survivors of childhood cancer. With overall pediatric cancer survival rates now 80%, the number of survivors will continue to grow.
The Childhood Cancer Survivor Study (CCSS), led by St. Jude's Children's Research Hospital, is one of the first to focus on how hypertension, diabetes, obesity, and elevated blood lipids contribute to cardiovascular disease in childhood cancer survivors. The research concentrated on risk factors that can often be modified with diet, exercise, and other lifestyle changes. The federally funded CCSS follows survivors of childhood cancer treated at 26 medical centers in the United States and Canada. St. Jude is its coordinating center. Its findings were reported in the Journal of Clinical Oncology (2013; doi:10.1200/JCO.2013.49.3205).
The risk was greatest for survivors whose cancer treatment included therapies associated with heart damage. The findings suggest that risk factors linked to lifestyle, particularly hypertension, intensify the impact of those childhood cancer treatments and accelerate development of heart disease.
The findings raise hope that prevention or treatment of such risk factors might help reduce heart-related death and disability among the nation's growing population of childhood cancer survivors. For survivors, treatment-related heart disease is a leading cause of noncancer death and disability.
The results reinforce the importance of survivors receiving annual medical screenings to check blood pressure, weight, cholesterol, and other health indicators, said the study's first and corresponding author Greg Armstrong, MD, an associate member of the St. Jude Department of Epidemiology and Cancer Control. Screenings have a track record of reducing heart disease in the general population and are recommended for childhood cancer survivors. "For doctors who are caring for survivors, the key message from this study is that aggressive management of hypertension is especially important for this population," Armstrong said.
The study included 10,724 childhood cancer survivors, half younger than 34 years and 3,159 siblings whose average age was 36 years and who had not had childhood cancer. The survivors were all at least 5 years from their cancer diagnosis and half had survived for more than 25 years.
While similar percentages of survivors and siblings reported at least two preventable risk factors, by age 45 years survivors were far more likely than the siblings to report severe, life threatening or fatal heart problems. For example, 5.3% of survivors, but 0.9% of siblings, reported a diagnosis of coronary artery disease and, 4.8% of survivors, but just 0.3% of siblings, reported suffering from heart failure. The difference was even more dramatic when investigators focused on survivors whose cancer treatment included either chest irradiation or chemotherapy with anthracyclines.