Radiation therapy that targets cancers in the chest area can tax the heart and trigger high levels of fatigue, breathing problems and a reduced ability to exercise, a new study suggests.
However, doing more physical activity before undergoing radiation therapy may help reduce these problems, the researchers added.
"This study suggests that when a patient is treated with thoracic radiation therapy, it can have a negative impact on their quality of life early on," said study author Dr. Sheela Krishnan, a fellow in the cardiovascular division of the Hospital of the University of Pennsylvania, in Philadelphia. "However, engaging in higher levels of physical activity before treatment may help to improve some of these symptoms over time," she added.
"This study also confirms that increasing levels of physical activity during treatment are associated with concurrent improvements in quality of life," Krishnan said.
"Though we cannot establish a clear causal relationship from these findings, it does emphasize that physical activity and quality of life are closely linked," Krishnan added in a news release from the American College of Cardiology.
The study included 130 patients, median age 54, who received radiation to treat breast cancer, lung cancer or lymphoma.
Lung cancer and lymphoma patients had an increase in fatigue and shortness of breath immediately after radiation therapy, which later improved, the investigators found.
Breast cancer patients had significant increases in physical activity and a decrease in fatigue over time after radiation therapy, the findings showed. Moderate to vigorous exercise before radiation treatment was associated with improvements in fatigue over time.
The differences between breast cancer and lung cancer and lymphoma patients may be due to differences in their radiation doses. However, after accounting for differences in chemotherapy and radiation doses, the researchers found that increases in physical activity over time were significantly associated with improvements in fatigue and shortness of breath.
The study was presented Friday at an American College of Cardiology course in Washington, D.C., on heart care for cancer patients. Such research is considered preliminary until published in a peer-reviewed journal.
Heart disease is the leading cause of death in cancer survivors, and it's estimated that 14.5 million cancer patients and survivors have significant heart disease risk factors.
"While our study is a small study, it suggests that high levels of physical activity prior to initiation of radiation therapy for cancer are associated with better physical functioning and quality of life with cancer treatment," Krishnan said. "Additional work is still needed to understand the types and timing of exercises that can bring about the greatest benefit."
Harvard Medical School has more on how cancer treatments may harm the heart.