Almost all of the patients overwhelmingly feel that such changes - whether a healthier diet or increased exercise or dietary-supplement use - improve their health and well-being.
This survey of more than 350 cancer patients in Washington is the first population-based study of its kind to look at changes in health-related behaviors up to two years following cancer diagnosis.
Ruth E. Patterson, Ph.D., R.D., and colleagues in Fred Hutchinson's Public Health Sciences Division led the study, which was supported by grants from the National Cancer Institute and funds from Fred Hutchinson. Researchers at Bastyr University in Kenmore, Wash., and Kaiser-Permanente in Oakland, Calif., also consulted on the project.
Patients were asked if they had made any major changes in diet, physical activity or supplement use to cope with cancer or reduce the risk of cancer returning or spreading. Psychological factors that might influence such changes, such as perceived health status and desire for personal control, also were assessed via questionnaire. Overall, the researchers found lifestyle changes were very common after a cancer diagnosis. Fifty percent of those surveyed started taking new dietary supplements (most common were multivitamins and/or vitamin E), 40 percent made dietary changes (most common was eating more fruits and vegetables), and 20 percent started a new physical activity (most commonly aerobic exercise). Two-thirds of patients reported making at least one such behavior change in the previous year, a quarter of those surveyed reported making two changes, and nearly 10 percent made improvements in all three areas.
"The vast majority of patients reported that these lifestyle changes improved their health and well-being," said Patterson, a member of Fred Hutchinson's Public Health Sciences Division and a research associate professor at the University of Washington School of Public Health and Community Medicine. Most of these changes were healthful and consistent with national cancer-prevention guidelines, such as eating more fruits and vegetables and less fat. Other changes, such as supplementation with vitamin C, garlic or echinacea, were more controversial.
"Because of the possibility of negative drug-herb interactions, as well as the possibility that supplement use could interfere with chemotherapy, health-care providers need to be aware that supplement use is common among cancer patients," Patterson said. "Anyone who is in active cancer treatment should talk to their medical team about the use of vitamins and supplements, which may need to be curtailed during treatment," she said.
Age, gender and treatment history affected the trend toward lifestyle change. For example, older patients (those over 60) were about half as likely to make dietary changes after a cancer diagnosis, female patients were twice as likely to take new dietary supplements, and those undergoing multiple treatments (radiation therapy, surgery and/or chemotherapy) were two to three times more likely to make changes in diet or physical activity. More educated patients also were more likely to make dietary changes and take new supplements.
Psychological factors associated with health-related behaviors included a strong desire for personal control and a conviction that one's health is largely within one's control. In contrast, a person's perceived health status - whether they thought themselves to be in excellent or poor condition - did not significantly impact lifestyle change.
The study findings suggest several key messages for health-care practitioners.
"These data suggest that cancer survivors are highly motivated to attempt lifestyle changes in diet, physical activity and dietary-supplement use as much as two years after diagnosis," Patterson said. "However, little is known about how lifestyle behaviors affect cancer recurrence and prognosis.
"Nonetheless, family, friends, media and personnel at health-food stores may readily give advice, much of which is offered with a degree of certainty that is out of proportion with available scientific evidence. Therefore, studies are needed that test hypotheses about changing health behavior to improve survival rates after a cancer diagnosis."
"Cancer survivors are motivated to make positive changes yet are vulnerable to nutrition misinformation," said David Grotto, a registered dietitian and spokesman for the American Dietetic Association. "Registered dietitians are uniquely qualified to guide cancer patients and survivors in adopting science-based, healthy dietary choices and lifestyle strategies."
The survey was based on telephone interviews with 356 adults who had been diagnosed with breast, prostate or colon cancer between February 1997 and December 1998. The group was divided equally among men and women, with equal representation among the three types of cancer. The participants were located through Fred Hutchinson's Cancer Surveillance System, a population-based registry of cancer incidence in western Washington that is part of a nationwide cancer registry funded by the National Cancer Institute.
One limitation to the study, Patterson noted, is that the survey was limited to patients with breast, prostate and colorectal cancer who were interviewed up to two years after diagnosis. Because survival rates for these cancers are high, motivations for making lifestyle changes among these patients may be different from those of patients with malignancies that have a poor prognosis, such as lung or pancreatic cancers.
In addition, the study population reflects western Washington demographics, which is predominantly white. Additional studies are needed to assess lifestyle changes among cancer patients in other racial/ethnic groups. "The results of these analyses indicate that cancer patients are often making lifestyle changes months to years after diagnosis and represent a group of adults who could benefit from counseling on diet and physical activity," Patterson said. "Health-care providers who work with cancer survivors need to be wary of dismissing or discounting dietary supplements or other nutritional or exercise regimens given that patients overwhelmingly feel that these activities improve their health and well-being."
The Fred Hutchinson Cancer Research Center, home of two Nobel Prize laureates, is an independent, nonprofit research institution dedicated to the development and advancement of biomedical technology to eliminate cancer and other potentially fatal diseases. Fred Hutchinson receives more funding from the National Institutes of Health than any other independent U.S. research center. Recognized internationally for its pioneering work in bone-marrow transplantation, the center's four scientific divisions collaborate to form a unique environment for conducting basic and applied science. Fred Hutchinson, in collaboration with its clinical partners, the University of Washington Academic Medical Center and Children's Hospital and Regional Medical Center, is the only National Cancer Institute-designated comprehensive cancer center in the Pacific Northwest and is one of 39 nationwide. For more information, visit the center's Web site at www.fhcrc.org.
Advancing Knowledge, Saving Lives
The Journal of the American Dietetic Association is the official research publication of the American Dietetic Association and is the premier peer-reviewed journal in the field of dietetics and nutrition.
Journal
Journal of the American Dietetic Association