Healthy living helps older, overweight cancer survivors reduce functional decline

May 12 2009

A home-based diet and exercise program reduced the rate of functional decline among older, overweight long-term survivors of colorectal, breast and prostate cancer, according to a study in the May 13 issue of JAMA, the Journal of the American Medical Association.

"In 2008, the Centers for Medicare & Medicaid Services declared mobility maintenance and functional independence among at-risk older individuals as the sole priority in aging research. Older cancer survivors represent an important target because cancer and its treatment are associated with accelerated functional decline," the authors write. The practice of healthy lifestyle behaviors may reduce risk for disease and functional decline. However, many older cancer survivors report poor lifestyle behaviors, and few meet recommended health promotion guidelines. "Lifestyle interventions may provide benefit, but it is unknown whether long-term cancer survivors can modify their lifestyle behaviors sufficiently to improve functional status."

Miriam C. Morey, Ph.D., of Duke University, Durham, N.C., and colleagues conducted a randomized, controlled trial that tested a home-based diet and exercise intervention and its effect on functional decline among 641 older (age 65-91 years), overweight (BMI 25 or greater and less than 40) long-term (5 years or greater) survivors of breast, prostate, and colorectal cancer. The participants were randomly assigned to an intervention group (n = 319) or delayed intervention (control) group (n = 322) in Canada, the United Kingdom, and the United States. The 12-month intervention consisted of a home-based program of telephone counseling and mailed materials promoting exercise, improved diet quality, and modest weight loss. Change in functional status was assessed using the physical function subscale of the Medical Outcomes Study Short-Form 36 (SF-36) questionnaire (score range, 0-100; a high score indicates better functioning). Other outcomes included changes in function on the basic and advanced lower-extremity function (i.e., use of legs) subscales of the Late Life Function and Disability Index (score range, 0-100), physical activity, body mass index and overall health-related quality of life.

The average physical function score at the beginning of the study was 75.7, which is comparable with the median (midpoint) score for men and women age 65 years or older. For the SF-36 physical function subscale, the average function scores declined less rapidly in the intervention group (average score change of -2.15) than in the control group (average score change of −4.84). There was a statistically significant difference between study groups in basic lower-extremity function as function changed negligibly in the intervention group, whereas the control group showed a decrease in function.

There were significant differences between the intervention and control groups for all targeted behaviors except endurance exercise frequency. Duration of strength training exercise and endurance exercise minutes increased in the intervention group and remained stable in the control group. The average intake of fruits and vegetables increased by 1.24 daily servings in the intervention group and by 0.13 daily servings in the control group. The average consumption of saturated fat decreased by 3.06 grams per day in the intervention group and by only 1.07 grams per day in the control group. Participants in the intervention group reported an average weight loss of 4.5 pounds, which was more than twice that reported by the control group (2.03 pounds).

Overall health-related quality of life decreased in every subscale in the control group throughout the 12-month period. In the intervention group, decreases in subscale scores were of lower magnitude and were sustained for overall health and mental health.

"In conclusion, this study provides data on a long overlooked, yet important faction in older long-term cancer survivors. Long-term survivors of colorectal, breast, and prostate cancer participating in a diet and exercise intervention reduced the rate of self-reported physical function decline in comparison with a group receiving no intervention," the researchers write. "Future studies should not only assess the effect on health and well-being, but also should address cost-related outcomes, especially given that the economic burden associated with functional decline and loss of independence is exceedingly high."