Health & Medicine

Exercise Boosts Tumor-fighting Ability of Chemotherapy

Benita Matilda
First Posted: Sep 19, 2014 06:30 AM EDT

Cancer patients undergoing chemotherapy might benefit from adhering to a regular exercise schedule, a new study has found.  

It is hard to ignore the health benefits of regular exercise and physical activity. The benefits extend much beyond weight management. One such added benefit of exercise is highlighted in the new study by researchers at the University of Pennsylvania who claim that, exercise boosts tumor fighting ability of chemotherapy.

The experiment, conducted on a mouse model suffering from melanoma, found that combining chemotherapy with exercise helped reducing the size of the tumors as compared to treating it alone with chemotherapy. This study was led by Joseph Libonati, director of the Laboratory of Innovative and Translational Nursing Research.

Exercise has been strongly recommended for patients battling cancer, as it boosts physical and psychological health. In this study, the researchers wanted to determine whether exercise helped protect against the negative cardiac-related side effects that occur with the use of the drug doxorubicin. Although this common cancer drug doxorubicin was effective in fighting against various types of cancer, it is known to destroy the heart cells causing heart failure in the longer run.

"The immediate concern for these patients is, of course, the cancer, and they'll do whatever it takes to get rid of it," Libonati said. "But then when you get over that hump you have to deal with the long-term elevated risk of cardiovascular disease."

Studies conducted earlier have highlighted that adhering to an exercise regime before starting chemotherapy helped protect the heart cells from the toxic effect of the cancer drug and only a few reports have looked at the benefits of exercise regime during chemotherapy.

To determine this, an experiment was conducted with four groups of mice. As a part of the study, all the mice were injected with melanoma cells in the scruffs of the necks. During the next two weeks, two groups were given doxorubicin in two various doses; while the other two groups received placebo. One mouse from one of the treated groups and one from the placebo group were kept on an exercise regime i.e. 45 minutes of walking for five days a week on a mouse-sized treadmill. The rest of the mice remained sedentary.

The researchers examined the creature's heart after the two-week trail using echocardiogram and tissue analysis. They noticed that doxorubicin lowered the heart function as well as the size. There was an increase in fibrosis. Those mice that exercised did not receive any protection from the damage.

But, they were surprised to notice that the mice that received both chemotherapy and exercise, had a dramatic drop in smaller tumors after two weeks as compared to the mice that just received the common cancer drug.

"If exercise helps in this way, you could potentially use a smaller dose of the drug and get fewer side effects," Libonati said.

Next, the team will investigate how exercise boosts the effect of doxorubicin. They, however, assume that exercise increases blood flow to the tumor bringing with it more of the drug into the bloodstream.

The finding was documented in the American Journal of Physiology.

See Now: NASA's Juno Spacecraft's Rendezvous With Jupiter's Mammoth Cyclone

More on SCIENCEwr