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Exercise May Improve Effectiveness of Chemotherapy

September 11, 2015

Exercise has several proven health benefits, including helping to control weight, improving your quality of life and lowering your risk for certain diseases.

But what’s the impact of exercise if you already have a chronic disease like cancer? That’s the question researchers have tried to answer in a recent study published in the Journal of the National Cancer Institute.

In the study, researchers found that mice that exercised had significantly reduced breast cancer tumor growth and an increase in cell death. Blood vessel growth increased by 60 percent and the transport of oxygen to the tumor also improved in mice that exercised compared to those that did not.

Based on these findings, researchers decided to test whether exercise also could improve the effectiveness of chemotherapy. They randomly assigned the mice to one of four groups: sedentary, exercise alone, chemotherapy alone or exercise plus chemotherapy. They found that the rate of tumor growth was significantly slower in mice treated with exercise plus chemotherapy compared to all other groups. Although the exercise alone and chemotherapy alone groups also had delayed tumor growth, there was no difference in tumor growth rate between those two groups, suggesting that exercise had similar effects as chemotherapy in this experiment.

The study suggests that exercise improved blood supply to the tumor tissue, which in turn increased oxygen delivery to the tumors. Increase in blood flow to the tumors could increase drug delivery to the cancers and improve the effectiveness of the chemotherapy drug. Exercise seems to stimulate tumor blood vessel growth and could open existing blood vessels.

These findings are encouraging, but we still need to do more research to understand the “why” behind these results, especially since the study was performed in mice and not humans. The benefit in this study seems to come from performing aerobic exercise, but there’s no evidence yet on other forms of exercise, including weight-bearing exercise. We also do not know how much exercise is enough to experience the benefits indicated in the study.

If you are undergoing treatment for cancer, talk to your doctor about how much and what kind of exercise you can do. The American Cancer Society has put forth guidelines for exercise during and after cancer treatment. The organization’s overall stance is that exercise has several benefits for people with cancer, such as reducing nausea, maintaining your physical abilities, minimizing muscle weakness and improving self-esteem. However, it also emphasizes that certain things will affect a person’s exercise regimen, including the type and stage of cancer, the type of treatment and your strength and energy level. Another important thing to keep in mind is that dehydration is a common side effect of chemotherapy. Keeping hydrated during chemotherapy is essential, so you should always have water with you if you exercise during treatment. You also should stick to moderate exercise and avoid vigorous workouts.

The key takeaway from this study is that exercise plays an important role in cancer patients and survivors, and that it should become an important component of cancer therapy. In cancer survivors, exercise has decreased the rate of recurrences. Evidence also shows that exercise is a safe and tolerable therapy that’s associated with many improved outcomes, such as fitness, quality of life, and reductions in symptoms such as fatigue in a number of cancer types, including breast cancer.

We still need to do more research to fully understand how exercise may improve cancer treatment and outcomes. However, these results give us more hope for how to better approach cancer treatment and give people battling this disease the best quality of life possible.