Exercise may boost cancer treatments
Exercise may help cancer patients recover. A new study at Duke University on mice found that aerobics reduced the growth of breast cancer tumors and made chemotherapy more effective at reaching the tumor.
As tumors develop, they create their own ecosystem by sending biochemical signals through the body to promote create blood vessels, which provide the tumor with more oxygen to enhance its growth. But this growth can get out of control and cause blood vessels to choke one another and ultimately reduce the oxygen supply. Instead of harming the tumor, that can cause it to become hypoxic--able to live with little oxygen. And that can make the tumor resistant to treatment because chemotherapy drugs and radiation are more effective in an oxygen-rich environment.
For this study, published in The Journal of the National Cancer Institute, scientists wanted to see if aerobic exercise could increase oxygen flow to tumors and reduce hypoxia. They conducted the study by implanting breast cancer cells into female mice. The mice were then divided into ones living in a sedentary environment and others in an active environment, including a running wheel.
The results showed that tumor growth was significantly slower in the exercising mice and their blood vessels contained more oxygen, making their tumors less hypoxic than in the sedentary mice.
The second part of the study involved another group of mice with breast cancer. Scientists divided the test group into quarters; one consisting of sedentary mice, one of active mice, one receiving a chemotherapy drug with no opportunity for exercise, and one receiving the drug in addition to an exercise wheel.
After 12 days – a substantial amount of time for mice – the animals were evaluated. Results revealed that the sedentary mice, whether or not they received chemotherapy drugs, had larger and hypoxic tumors, and the groups with just exercise and just chemotherapy drugs showed slower tumor growth. The group with the best outcome had received chemotherapy and exercise, and had significantly smaller tumors.
The findings indicate that exercise could potentially alter the biology of some cancerous tumors, making them easier to treat. Because this study was small and involved mice, much more research is needed to determine if exercise will in fact aid human cancer patients.