STOCKHOLM, Sweden, March 24 (UPI) -- Swedish researchers say cancer radiotherapy can increase the risk of cardiovascular disease and the cause might be changes in arterial gene expression.
Karolinska Institute scientists say their new study suggests sustained inflammation induced by post-radiotherapy changes in the gene expression in the arteries could be causing increases in the risk of cardiovascular disease in the same part of the body. For example, they point to heart attacks occurring after left-side breast cancer treatment, or strokes occurring after the treatment of head, neck or brain tumors.
"Studies have been hampered by the fact that the disease process is so slow," said Karolinska researcher Martin Halle. "Cell studies and animal studies are best suited to the more immediate effects, and studies on human subjects have been ruled out for ethical reasons."
But in the new study, the researchers found irradiated arteries showed signs of chronic inflammation and an increase in activity of a genetic factor known for playing a key part in the development of atherosclerosis. The greater inflammatory gene expression was visible for several years after irradiation, and might, the researchers said, explain why cancer patients can suffer cardiovascular disease many years after radiotherapy.
"Hopefully, these findings will one day help medicine to mitigate the side effects by administering radiotherapy in combination with an anti-inflammatory treatment," Halle said.
The study is presented in the Journal of the American College of Cardiology.