Physical activity and obesity in Canadian cancer survivors

A new study reveals that many cancer survivors are inactive and obese, which may negatively affect the control of their disease.

The findings, which come from a study of cancer survivors in Canada, show that a cancer diagnosis does not appear to prompt significant behavior change and that interventions to increase physical activity and promote better eating habits among cancer survivors are warranted. The study is published in the June 1, 2008 issue of CANCER, a peer-reviewed journal of the American Cancer Society.

Obesity and physical inactivity are known to be detrimental to health, and in cancer patients, studies have linked these factors to negative outcomes including disease recurrence, cancer-specific death and reduced quality of life. However, few studies have looked at the prevalence of physical activity and obesity in populations of cancer survivors.

To determine this prevalence and compare it to individuals without a history of cancer, Kerry S. Courneya, Ph.D. of the University of Alberta in Edmonton analyzed data from the 2005 Canadian Community Health Survey consisting of computer-assisted interviews of more than 114,000 adults. Survey participants reported their cancer history, height and body weight (to calculate body mass index), and participation in various leisure time activities.

The study revealed that fewer than 22 percent of Canadian cancer survivors were physically active, with the lowest rates reported by male and female colorectal cancer survivors, female melanoma survivors and breast cancer survivors. Also, nearly one in five (18 percent) of cancer survivors was obese, and one in three (34 percent) was overweight with little variation among the cancer survivor groups. The authors concluded that Canadian cancer survivors have low levels of physical activity and a high prevalence of obesity that are comparable to the general population.

However, some differences were found between cancer survivors and those without a history of cancer. Prostate cancer survivors were more likely to be active and less likely to be obese than men without a history of cancer, and male skin cancer survivors were more likely to be active than their disease-free counterparts. Also, obese breast cancer survivors were less likely to be active compared with obese women without a history of cancer. “This finding is cause for concern because physical activity may be particularly important for obese breast cancer survivors,” the authors note. Studies suggest that obese breast cancer survivors may particularly benefit from higher physical activity levels in terms of preventing disease recurrence and improving quality of life.

In light of their findings, the authors recommend that lifestyle interventions be implemented to increase physical activity and promote a health body weight among cancer survivors.