Saturday, 5 May 2012

The Effects of Exercise on Cancerous Tumors, Cancer Patients and Cancer Survivors

There is convincing evidence that regular exercise reduces the risk of several major cancers. Research has shown that many major cancers are caused, at least in part, to a lack of sufficient physical activity. 

However, the medical community is still relatively unclear about whether exercise has a beneficial effect on a cancerous tumor once it starts to develop. Preliminary research suggests that exercise may abate the growth of cancerous tumors and possibly prevent their recurrence.         

Can Exercise Slow Down the Growth of Cancerous Tumors?

The answer is not a resounding “yes,” but there is compelling epidemiological data and experimental results  indicating that regular exercise may retard the growth of certain cancers.     

For example, researchers studied the effects of exercise on the development of sarcoma tumors in mice liver. There were five groups of mice in the study, seven mice in each group. The groups consisted of:

A.        Control group of mice
B.         Control group of mice with implanted sarcoma tumor cells
C.         Exercised trained mice whose exercise was terminated after implantation of sarcoma tumor cells
D.         Exercised trained mice who continued exercising for 18 days after implantation of sarcoma tumor cells
E.         Continuously exercised mice who never received sarcoma tumor cells

The exercised mice in Groups C and D had undergone swimming training one hour per day, five days a week for ten weeks before receiving the tumor cells. Groups C and D mice also continued to receive tumor cells after the ten-week training period.    

The size of the tumors in Group D mice, i.e., those exercised-trained mice that continued to exercise after receiving the tumor cells, was 50% smaller compared to the size of the tumors in Group B mice, the control group that did not exercise at all but received only tumor cells. In other words, the data proved that exercise had slowed down the growth of the tumors.  

Interestingly, the exercise that group C performed but did not continue after implantation of tumor cells had some beneficial effects on tumor development, but the difference was not statistically significant. 

The decrease in tumor size was more evident in the group D mice, or those that exercised during cancer development. The exact explanation for this is not yet known. Some researchers believe that the exercise during cancer development somehow altered the angiogenesis of the tumors, caused energy to be utilized differently or altered the immune system.

Whatever the physiological explanation, cancer patients should to talk to their oncologists to find out whether engaging in an exercise program is medically appropriate. Even with respect to mesothelioma, a rare soft tissue sarcoma, exercise may have a palliative effect, as shown by the mice liver study.

How Can Exercise Otherwise Aid in the Treatment of Cancer?

Beside the potentially positive effect that regular exercise has on the growth of cancerous tumors, exercise does much more for the general health and well-being of the cancer patient and the cancer survivor. 

Participation in an exercise program during cancer treatment can alleviate some of the side effects of cancer therapies, such as fatigue and nausea. Exercise has been shown to reduce these side effects in breast and prostate cancer patients by reducing toxicity levels in the body. 

Mental health benefits include reduced stress, increased self-worth and improved quality of life. There is also evidence that exercise diminishes clinical symptoms of depression.  Moreover, with respect to cancer survivors, exercise has been shown to help prevent a relapse of the disease by strengthening the immune system.

Consequently, many oncologists, cancer patients and cancer survivors acknowledge the need to engage in a structured exercise program as part of treatment for mesothelioma and other cancer treatment and prevention regimens. Physicians and patients should work together to design a professionally supervised exercise program that is tailored to the patient’s specific cancer, treatment type and fitness level.  

Further reading below: