Chemotherapy and radiotherapy can be life-saving treatments for cancer sufferers, but their toxic effect on the heart mean those who have survived childhood cancer face a higher risk of developing heart disease, according to a study.
Researchers led by a team from the University of Minnesota Medical School carried out a study on more than 14,000 people who survived cancer in childhood and found the post-effects of having the treatment can last for up to 30 years.
The study, which is the largest ever analysis of heart disease among survivors of childhood and teenage cancers, found effects on the heart are more distinct than previously thought and occur with lower doses of drugs.
Patients looked at in the study, published online in the British Medical Journal (BMJ), were aged six on average at diagnosis, with 40% diagnosed under the age of five.
More than half of all survivors received a combination of chemotherapy and radiotherapy, while 11% received radiotherapy and surgery.
Another 18% received chemotherapy and surgery and a tiny proportion (0.3%) received only radiotherapy.
Over a 30-year follow-up period, the risk of an adverse cardiac event - such as heart failure, heart attack, inflammation or abnormalities with the heart valves - was five to six times higher among cancer survivors than among their brothers and sisters who did not have cancer.
This was true even when factors likely to influence the results, such as smoking, were taken into account.
The authors said: “The incidence of each cardiovascular outcome increased with time from diagnosis, which suggests that the long term impact of treatment on the health of cancer survivors will be substantial.”