Childhood cancer is very rare. And when it does strike, most kids live through it. The lifesaving treatments affect young bodies though, and those effects can show up later in life.
Adults who were treated for cancer as children were more likely to develop cardiovascular disease than the general population, a new study has discovered.
The researchers examined the incidence of and modifiable risk factors for cardiovascular disease in childhood cancer survivors.
Monitoring, control and early treatment of these risk factors may minimize risks of premature cardiac events, the researchers concluded.
Gregory T. Armstrong, MD, MSCE, in the Epidemiology and Cancer Control department of St. Jude Children's Research Hospital in Memphis, TN, and colleagues examined how modifiable cardiovascular risk factors impact cardiac events in adult childhood cancer survivors.
In the study’s background, the authors explained that radiation therapy directed at the chest is associated with increased risk of myocardial infarction (heart attack), congestive heart failure (weakened heart muscle that can’t pump blood through the body very well), valvular heart disease (diseased heart valves) and arrhythmias (irregular heart beat).
Anthracycline chemotherapy, a medicine commonly used in childhood cancers that kills cancer cells throughout the body, is also known to increase heart failure risks.
A total of 10,724 five-year survivors of childhood cancer and 3,159 siblings in the Childhood Cancer Survivor Study participated in this research.
The median (middle) age of survivors was nearly 34 years. They had been treated for childhood cancer between 1970 and 1989.
Study members had received treatment for a range of childhood cancers, including leukemia, lymphomas, soft tissue sarcoma and bone tumors.
Survivors had been treated for cancer a median of 26 years earlier.
Upon enrollment (1994-1999), both the survivors and siblings completed a questionnaire that asked about their personal and family medical history, including cardiovascular issues.
Two follow-up surveys were completed during 2007-2009.
Cardiovascular disease was much more common in the survivors than in the siblings, the researchers uncovered. The study's results revealed the following:
- 5.3 percent of survivors had coronary artery disease by the age of 45, compared to 0.9 percent of siblings.
- 4.8 percent of childhood cancer survivors suffered from heart failure, compared to 0.3 percent of siblings.
- 1.5 percent of the adult survivors had valvular heart disease as opposed to 0.1 percent of siblings.
- 1.3 percent of survivors had arrhythmia versus 0.4 percent of siblings.
- 10.3 percent of survivors had two or more cardiovascular risk factors, while 7.9 percent of siblings reported having more than one risk factor.
Hypertension (high blood pressure) greatly increased the risks of all cardiovascular disease categories.
Those who had high blood pressure had a six times greater risk of coronary artery disease and arrhythmia, 19 times higher risk of heart failure, and nearly 14 times greater chance of valvular heart disease, compared to those who did not have high blood pressure.
Hypertension also independently was associated with an increased the risk of cardiac death by 5.6 times.
The authors wrote, “Early diagnosis and appropriate management of hypertension, diabetes, dyslipidemia (high cholesterol), and obesity in at-risk, aging survivors may substantially reduce the risk of premature cardiac disease."
This study was published September 3 in the Journal of Clinical Oncology.
The research was funded by the National Cancer Institute and by the American Lebanese Syrian Associated Charities.
No conflicts of interest were disclosed.