Study of female colorectal survivors looks at effects of weight loss

Loyola University Medical Center is one of a handful of centers nationwide conducting a National Cancer Institute-funded research study that offers nutrition counseling and free membership to a weight-loss facility to help women who have had colon or rectal cancer reach a healthy body weight in one year.

There are more than 600,000 female colorectal cancer survivors in the U.S. and more than half are estimated to be overweight. Despite clear recommendations to increase physical activity, only about one-third of cancer survivors engage in the recommended 30 minutes of moderate-intensity physical activity at least five days per week.

An estimated 57 percent of women diagnosed with colorectal cancer survive at least 10 years after diagnosis. Recent data suggest that women with a body mass index of less than 25 have a higher 10-year survival rate, as do those with higher levels of physical activity and diets high in fruits and vegetables and low in saturated fat. But these are preliminary findings; no completed clinical trials have yet tested the effects of weight loss via physical activity and dietary change on survival among overweight or obese colorectal cancer survivors.

Women who volunteer for the study will receive nutritional counseling over the phone for 12 months to trim their calorie intake and access to a local facility to participate in a fitness program at least three times per week. The fitness program features bidirectional, pneumatic resistance training exercise combined with low-impact aerobic exercise for 30 minutes. This combination may be more manageable for women who would hesitate to try more traditional types of cardiovascular exercise.

Results from the Women's Healthy Eating and Living Randomized Trial suggested that the protective effect of a diet high in vegetables, fruit and fiber and low in fat may be limited to women who also engage in higher levels of physical activity. And moderate-intensity physical activity has been shown to reduce the risk of colorectal cancer recurrence and lower mortality rates.

To date the majority of lifestyle modification studies among cancer survivors have tested either a dietary intervention or a physical activity intervention. An editorial in the 2007 Journal of Clinical Oncology discusses the promise of combining physical activity and dietary interventions to improve cancer outcomes. The new study, known as S1008, is the first long-term intervention study of post-treatment cancer survivors to take this combined approach.