WASHINGTON, DC—The role of physical activity and a healthy lifestyle was at the center of discussion at the 5th Biennial Cancer Survivorship Research Conference. Evidence increasingly points to the importance of exercise and a healthy diet in the years after treatment, and many researchers are currently exploring effective physical activity and weight loss interventions.
Melinda L. Irwin, PhD, MPH, of Yale School of Medicine, New Haven, Connecticut, gave an overview of the state of the research on how a healthy energy balance affects quality of life in survivorship, with lower cancer mortality and morbidity.
“The evidence is growing,” said Irwin, “and it’s pretty suggestive of an association between higher levels of activity and an improved survival.”
She pointed to a number of seminal studies over the past decade, including Calle and colleagues’ 2003 study, which established that obesity affects survival adversely1; and Ibrahim and Al-Homaidh’s 2010 meta-analysis, which found a 50% reduction in breast cancer death with 2 to 3 hours per week of moderate physical activity.2
But the implementation of physical activity interventions in clinical care lags behind, Irwin said. “Unfortunately, current cancer therapies do not address the association of lifestyle factors on prognosis and survivorship.”
The Transdisciplinary Research on Energetics and Cancer Centers (TREC), a National Cancer Institute–funded 10-year research initiative on “the biology, genomics, and genetics of energy balance to behavioral, socio-cultural, and environmental influences upon nutrition, physical activity, weight, energetics, and cancer risk” has been at the forefront of measuring such interventions, and Irwin reported a number of findings from TREC’s 2009 conference. TREC has funded four sites, and six more will be funded in the coming year.
Irwin also pointed out a number of research gaps. There is a need for more cohort studies assessing the relationship between energy balance and prognosis; measured body composition; weight loss/gain and prognosis; subtypes of cancers, genes, and other exposures; biomarkers; diverse cancer populations; and collaborations that allow for combined analyses. There is also a need for high-quality randomized clinical trials looking at survival, recurrence, and second primary outcomes; biomarker end points; diverse populations; and recruitment and adherence strategies.
New exercise guidelines There is hope that new exercise guidelines developed by an interdisciplinary team and released in the July 2010 issue Medicine & Science in Sports & Exercise will be a big step in the right direction. Anna L. Schwartz, FNP, PhD, FAAN, of Arizona State University, Phoenix, discussed the new guidelines in a presentation.
“This is the way the future is going to be. We’re going to diagnose people with cancer: ‘sorry, you’ve got Brand X cancer, you’re going to the cancer and exercise club to get part of your care.’”
For most cancer survivors, it is appropriate to follow the protocol laid out for older people in general, as described in the US Department of Health and Human Services’ Physical Activity Guidelines for Americans3: 150 minutes of moderate-intensity or 75 minutes of high-intensity exercise per week; and two to three sessions of resistance exercise per week. Above all, says Schwartz: “Avoid inactivity” and “do whatever you want to do, whatever it is you like to do.”
Schwartz also discussed the new cancer exercise trainer certification developed by the American College of Sports Medicine and the American Cancer Society.
Physical activity and weight loss interventions Cheryl Rock, PhD, RD, of the University of California, San Diego Medical Center, Moores Cancer Center, reviewed physical activity and weight loss interventions, which can have a positive affect across the board, including with “cardiovascular disease, diabetes, osteoarthritis, and all the other things that plague us as we get older, and certainly are highly prevalent in cancer survivors.”
Unexplained weight loss can be a symptom of recurrence, so survivors sometimes feel apprehensive about slimming down—but many are starting out too heavy in the first place. “Although it’s true that while going through treatments it’s important to be cognizant of not losing muscle mass and maintaining healthy weight, it’s also true that nowadays, given the higher prevalence of obesity in the United States, many cancer patients when they are diagnosed are actually overweight at that time,” she explained.
Body image issues can even mislead oncologists, she said. “The whole healthcare team has to be engaged in this process: Weight loss doesn’t necessarily mean wasting.”
Kathleen Y. Wolin, ScD, of Washington University, St. Louis, Missouri, presented an overview of studies on physical activity and cancer survivorship. Although Wolin was adamant in asserting the importance of exercise, there are still major research gaps to be filled: bone and fracture risk; cardiovascular effects; recurrence and survival end points; and the “dosage” questions—how many hours, how often, at what intensity?
She said that researchers should also focus on more newly prevalent types of exercise, such as the many varieties of yoga. There is also the question of how to make exercise accessible to a diverse group of people, including rural residents with no access to sidewalks or low-income people with less access to gyms. So far, research has largely focused on white and middle class survivors. Some studies also lack methodological rigor: too many before and after comparisons and nonrandomized trials. That said, the benefits and low risk of exercise for cancer survivors are clear.
“If you take away nothing else from this presentation, it’s that exercise is safe for people to do during breast cancer treatment,” Wolin concluded.
Other presentations described innovative approaches for increasing physical activity among diverse populations of survivors.
Susan L. Beck, PhD, APRN, FAAN, of the University of Utah College of Nursing, Salt Lake City, and other researchers investigated the “Effect of Resistance Exercise for Older Cancer Survivors” and found “initial support for the feasibility and efficacy of eccentric exercise to improve fatigue and weakness in older adult cancer survivors,” although there was not a demonstrable effect on health status.
The study compared a 12-week eccentric resistance exercise program administered to 40 elderly survivors against a control group. Baseline measures on the General Fatigue Scale, General Weakness Scale, and the Medical Outcomes Study 36-Item Short-Form Health Survey (MOS SF-36) were compared with posttest measures. The group undergoing the exercise intervention registered a 0.98 mean change on the General Fatigue Scale, compared with 0.45 for the control group; the experimental group’s mean change on the General Weakness Scale was 1.01, compared with just 0.09 for the nonexercise group. The researchers call for the study to be expanded in a larger randomized clinical trial.
Kerri Winters-Stone, PhD, and her fellow researchers at the College of Health and Human Sciences, Oregon State University, Corvallis, are undertaking a randomized clinical trial comparing aerobic with resistance exercise in sedentary elderly breast cancer survivors (BCS). Preliminary findings after 3 months “show that short-term, low-intensity exercise of any type may improve endurance, strength, and function in older BCS, but gait speed may be more responsive to aerobic exercise,” although more differences between the exercises may only become clear later in the trial. Seventy-nine women are participating in either resistance, aerobic, or a controlled flexibility exercise group.
Encouraging cancer survivors to exercise and pursue a healthy lifestyle can be a challenge, especially because interventions must be tailored to factors such as age. Researchers Carolyn B. Rabin, PhD, and Bess H. Marcus, PhD, from the Miriam Hospital/Alpert Medical School of Brown University, Providence, Rhode Island, gathered qualitative and quantitative data from 10 young adult survivors (aged 18-39 years) in an effort to adapt a theoretically grounded web-based exercise intervention to their age group. In addition to goal setting, activity logging, tailored feedback, and other features already tested with sedentary adults, researchers considered the addition of a link to cancer survivor–specific exercise information and an online forum where survivors could communicate with one another. Most surveyed survivors rated the proposed additions positively; some suggested adding an “Ask the Expert” feature and more information on nutrition.
When encouraging exercise, is it better to emphasize the pitfalls of a sedentary lifestyle or the joys of fitness? In “The Effects of Framing on Exercise Levels in Colorectal Cancer Survivors,” Isaac M. Lipkus, PhD, and fellow researchers at Duke University, Durham, North Carolina, compared two minimal interventions (a mailed brochure), one with “gain” framing, and another with “loss.” Of the 149 eligible participants recruited from state cancer registries, 137 (92%) early-stage colorectal cancer survivors (6 months to 5 years after diagnosis) completed the 1-month follow-up survey. At baseline, participants engaged in moderate to vigorous exercise an average of 39 minutes per week, which increased to 115 minutes at follow-up. No difference was observed between the two different frames, however; and researchers concluded that “future research should investigate methods to increase the potency of these interventions to increase further physical activity in this population.”
Melissa F. Miller, PhD, MPH, of the Cancer Support Community’s Research and Training Institute, Washington, DC, looked into the way different factors influenced survivor response to Cancer Transitions, a 6-week program that provides cancer survivors exercise and nutrition support. The study evaluated a pilot program at 10 centers from 2007 to 2008. The program was already known to improve health-related quality of life and physical activity, but it was not known what factors made someone more or less receptive to the program. The study investigated predictors of physical and emotional functioning and found that “several factors (weight status, program attendance, income, race, and time since treatment) predicted greater response to Cancer Transitions. Research is needed to evaluate the value of targeting and/or tailoring healthy lifestyle support programs for cancer survivors.”
Race and culture can also play a role in survivorship care. M. Tish Knobf, PhD, RN, FAAN, AOCN, and fellow researchers at Yale University piloted a 6-week program to encourage healthy lifestyle and physical activity among African-American BCS. A convenience sample of 40 women was recruited from support groups, hospitals, and community outreach. Preliminary data were presented for 30 women measured for empowerment (Self Efficacy for Exercise), functional ability (MOS SF-36), quality of life (Functional Assessment of Cancer Therapy-Breast), and healthy lifestyle (Health Promotion Lifestyle Profile II) at baseline, immediate postprogram, and 3 months later. Improvements were found in quality of life, emotional well-being, health promotion, health responsibility, physical activity, nutrition, and spiritual growth, but not for empowerment or functional ability. The researchers suggest that “a culturally designed psychoeducational intervention focused on physical activity and healthy eating can positively influence lifestyle behaviors and quality of life for African-American breast cancer survivors.”
Making physical activity promotion an integral part of follow-up care, rather than something separate or elective, could boost its efficacy. Bernardine M. Pinto, PhD, and fellow researchers at Miriam Hospital/Alpert Medical School of Brown University, Providence, Rhode Island, evaluated the efficacy of Moving Forward with Life, a program that provided oncologists and surgeons with training in giving brief physical activity advice during follow-up visits with BCS. All 192 women received the advice and took part in 12 weeks of telephone counseling. Then, they were randomized into either an extended advice intervention group (based on the Transtheoretical Model and Social-Cognitive Theory) or a brief advice control group. The researchers found that those receiving extended advice were more likely to exercise and increase the number of minutes exercising per week.
Jennifer R. Klemp, PhD, MPH, and fellow researchers at the University of Kansas Medical Center’s Breast Cancer Survivorship Center, Kansas City, presented preliminary evidence suggesting that a 6-month intervention focusing on diet, exercise, and behavioral weight loss in overweight postmenopausal BCS can be effective in reducing weight, achieving favorable biomarker changes, and improving quality of life. Of 84 BCS who had completed chemotherapy at least 3 months before and had a body mass index of 25 to 45, 52 agreed to participate and six did not complete the trial. Participants engaged in 225 minutes a week of moderate-intensity aerobic exercise, light resistance training, a 1200- to 1500-calorie-per-day diet, and group meetings on behavior modification. The researchers used a number of measures to assess participants at baseline and postintervention, including anthropometrics, body composition (dual x-ray absorptiometry), serum biomarkers (insulin, leptin, and adiponectin), fitness test, and survey questions on eating habits and quality of life. Preliminary data for 32 of the women showed significant weight loss, positive biomarker change, and improved quality of life.
Fewer studies have been conducted with lung cancer survivors for obvious reasons: the disease still has a high mortality rate and is characterized by shortness of breath and fatigue. Preliminary findings from a new study show there are significant barriers to recruiting patients for such interventions. In “Feasibility of Implementing a Physical Activity Trial with Sedentary Survivors of Early State, Non–Small-Cell Lung Cancer (NSCLC),” Jamie S. Ostroff, PhD, of Memorial Sloan-Kettering Cancer Center, New York, and other researchers recruited 70 sedentary and disease-free survivors between 1 and 10 years after treatment. Participants were separated into a 12-week home-based physical activity program emphasizing walking, upper body and breathing exercises, or a wait-list control group. Of 51 eligible patients, just 28 enrolled. Patients who refused the program were of a similar average age and gender, and cited low motivation for exercise, travel distance to the cancer center, and health concerns. Similarly, in another study, researchers in Denmark found “that patients failed to comply with home-based exercise,” and that supervised exercise was preferable.
Emily Jo Rajotte, MPH, of the Fred Hutchinson Cancer Research Center’s Survivorship Program, Seattle, Washington, and other researchers undertook a study of a community-based exercise program. They found significant improvements in fatigue, physical function, musculoskeletal symptoms, mental health, social support, blood pressure, weight, waist circumference, strength, and flexibility. The program resulted in few injuries or lymphedema events, and 70% of participants reported continued exercise 6 months later. Exercise and Thrive was a 10-week group exercise program organized by the YMCA of Greater Seattle, Hutchinson Center’s Survivorship Program, and LIVESTRONG. Of 157 survivors observed, pre- and postsurvey and physiologic data were available for 68% of participants.
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