More than 65 percent of adult cancer patients in western Washington make one or more health-related lifestyle change in response to their cancer diagnosis, according to a Fred Hutchinson survey published in the March edition of the Journal of the American Dietetic Association.
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 after cancer diagnosis.
Dr. Ruth Patterson in the Public Health Sciences Division led the study, which was supported by grants from the National Cancer Institute and funds from Fred Hutchinson. Coauthors included Drs. Marian Neuhouser, Stephen Schwartz and Deborah Bowen, also of PHS, and colleagues at Bastyr University in Kenmore, Wash., and Kaiser-Permanente in Oakland, Calif.
Patients were asked if they had made 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, researchers found lifestyle changes were 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, also a research associate professor at the UW School of Public Health and Community Medicine.
Most of the changes were healthful and consistent with national cancer-prevention advice, such as eating more fruits and vegetables and less fat. Other changes, such as supplemental 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."
Age, gender and treatment history affected the trend toward lifestyle change. For example, patients 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 did not significantly impact lifestyle change.
The findings point to key messages for health-care practitioners.
"These data suggest 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."
The phone survey interviewed 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.
Up to two years after diagnosis
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.
Also, the study population reflects predominantly Caucasian western Washington. More studies are needed among other racial/ethnic groups.
"The results indicate that cancer patients often make lifestyle changes months to years after diagnosis and could benefit from counseling on diet and physical activity," Patterson said.
"Providers who work with survivors need to be wary of dismissing or discounting dietary supplements or other nutritional or exercise regimens."