Science Article
April 4, 2003
Cancer diagnosis motivates change ...
… but women who learn that they have breast cancer slow their physical activity
 Drs. Ruth Patterson (left) and Marian Neuhouser confer about their study of physical activity following cancer diagnosis. Photo by Todd McNaught |
By KRISTEN WOODWARD
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.
Psychological factors
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.”
By BARBARA BERG
Women cut back on their physical activity after learning they have breast cancer, a move that researchers worry may lead to poorer prognosis.
A study co-authored by Dr. Anne McTiernan in the Public Health Sciences Division finds that women decrease their physical activity an average of two hours a week following breast-cancer diagnosis. The sedentary trend was most pronounced among obese women and those who received the most intensive cancer treatment.
“Breast-cancer patients who are overweight or obese have poorer survival compared with normal-weight women,” McTiernan said. “Since reduced physical activity is associated with weight gain, we’re concerned that breast-cancer patients who reduce their activity levels might gain weight, which would negatively impact their survival.”
The analysis was based on data collected in the Health, Eating, Activity and Lifestyle (HEAL) Study, the first population-based research to investigate, among other things, changes in physical-activity levels before and after breast-cancer diagnosis and to assess how disease stage, treatment, age and body-mass index influence these changes.
Several collaborators
The results are published in the April 1 edition of Cancer. The study was led by Dr. Melinda Irwin, an assistant professor at the Yale School of Medicine and a former center postdoc, and included collaborators at the University of New Mexico, the University of Southern California, the University of Pittsburgh and the National Cancer Institute.
Previous studies at Fred Hutchinson and elsewhere have found a connection between elevated body-mass levels at time of breast-cancer diagnosis and poorer survival. Scientists suspect the increased risk may be due to higher levels of estrogen produced by fat cells in menopausal women. Estrogen is a known promoter of breast cancer.
In contrast, few studies have addressed the connection between weight gain and disease outcome after diagnosis and during treatment. Weight gain and subsequent, increased body fat occur in more than 80 percent of women with breast cancer during the first year after diagnosis, with gains commonly ranging between 5 and 13 pounds. A combination of factors, including effects of the treatment itself, increased caloric intake and decreased physical activity, likely contribute to the added pounds and body fat.
To address factors that contribute to post-diagnosis weight gain, researchers surveyed 856 breast-cancer patients in Washington state and New Mexico about changes in their physical activity levels for four to 12 months after diagnosis, compared to the year before diagnosis. In-person interviews assessed the type, duration and frequency of activities, as well as participants’ height and weight.
Information about women’s stage of disease and treatment was obtained from the center’s Cancer Surveillance System and from the New Mexico Tumor Registry as well as from medical records.
Most women reported being less physically active after diagnosis regardless of their disease stage. The average decrease was two hours per week, or 11 percent, from pre-diagnosis levels of activity.
Women treated with a combination of surgery, radiation and chemotherapy decreased their physical activity by half, while women treated with surgery or radiation alone reported reduction in activity closer to 25 percent.
Weight prior to diagnosis was linked to the level of reduction in activity, with obese or overweight women reporting declines of 41 percent and 36 percent, respectively, compared to normal weight women, whose activity declined by 24 percent.
Investigators think the drop in physical activity accounts for typical post-diagnosis weight gain. McTiernan, co-author of “Breast Fitness,” a book to help women reduce breast-cancer risk and recurrence through exercise, said studies are under way to determine the effect of activity on survival.
‘Poorer survival’
“We know that overweight and obese breast-cancer patients have poorer survival,” she said. “We still do not know if exercise per se is enough to improve survival, or if women also need to make dietary changes.”
Results from those studies may not be available for several years, but McTiernan touted exercise for women with breast cancer, many of whom report improved strength, coping skills and quality of life when they remain active after diagnosis.
“Physical activity is a good thing for breast-cancer patients and survivors,” she said. “Patients who are suffering from fatigue during treatment may want to do easy exercises such as stretching, yoga, or slow walking. After treatment, they can gradually increase their activity, preferably at least to the level they were at before diagnosis.”
