Making lifestyle changes ‘part of the cancer treatment conversation’
Approximately 42% of cancer cases are linked to modifiable risk factors that are well-known to the general public, according to the American Cancer Society.
The benefits of exercise, smoking cessation and a healthy diet are an integral part of public health messaging.
Yet this knowledge — and the research backing it — does not always extend to patients who already have been diagnosed with cancer. Forty-five percent of cancer deaths also are associated with modifiable risk factors, but no clear scientific consensus has been reached on lifestyle recommendations for this population.
“By far, we have far more research telling us about how diet, physical activity and lifestyle are related to cancer risk,” Kim Robien, PhD, RD, CSO, FAND, associate professor at Milken Institute School of Public Health of George Washington University and a member of George Washington University Cancer Center, told HemOnc Today. “We don’t have as much research to make recommendations about how diet and physical activity help people as they’re going through treatment, or after treatment as cancer survivors.”
As oncologists facilitate all other aspects of a patient’s cancer treatment plan, they would seem to be the ideal providers to introduce the topic of a healthy lifestyle. Yet the lack of data — and an equally relevant lack of time — have led to reluctance among many oncologists to initiate this conversation.
“Several survey-based studies have indicated that both oncologists and patients are very interested in diet, exercise and other lifestyle conditions. However, the topic is rarely discussed unless a patient asks, for several reasons,” Neil M. Iyengar, MD, assistant member and attending physician in the breast medicine service at Memorial Sloan Kettering Cancer Center, told HemOnc Today. “Their first priority is to discuss cancer treatment, and until a trial shows that diet and/or exercise improves cancer-related outcomes, such lifestyle interventions are not part of the cancer treatment conversation.
“We know, generally, that maintaining a healthy weight and eating a diet rich in fiber and plants is healthy, but current clinical guidelines for diet and exercise after a cancer diagnosis provide vague ‘one-size-fits-all’ recommendations,” Iyengar added.
HemOnc Today spoke with oncologists about how smoking cessation, a healthy diet and exercise may improve cancer outcomes; the lack of guidelines that exist for patients with cancer on a healthy lifestyle; and how oncologists can integrate these practices into their care management.
The importance of smoking cessation
It is clearly understood, by oncologists and the population at large, that cigarette smoking and cancer are causally linked.
Likewise, smoking can sabotage treatment efficacy and outcomes of patients diagnosed with cancer.
A 2014 Surgeon General’s report found that smoking among patients with cancer was associated with various adverse outcomes, including increased overall and cancer-specific death, risk for second primary cancer, and additional toxic effects from cancer treatment.
Additionally, a study modeled on data from that Surgeon General’s report estimated that the excess cost for cancer treatment among patients who continue to smoke could reach $3.4 billion per year compared with the cost if those patients stopped smoking. This added cost was attributed to first-line treatment failures among patients who continued to smoke.
Despite these clear incentives to quit, an estimated 64% of smokers with cancer continue to smoke after their diagnosis.
“There’s a lot of evidence out there that shows that a number of people who smoke at the time of a cancer diagnosis continue to smoke even after that diagnosis,” Michael B. Steinberg, MD, MPH, FACP, professor of medicine in the division of general internal medicine at Robert Wood Johnson Medical School at Rutgers, the State University of New Jersey, and a HemOnc Today Editorial Board Member, told HemOnc Today. “That just speaks to the addictive nature of tobacco use. It’s not the kind of thing where, once you hear bad health news, you immediately just quit on your own.”
The reasons for which patients may continue to smoke after a cancer diagnosis are complex and manifold, experts said. Patients may feel a sense of resignation and pessimism about the future and may lack the motivation to make positive lifestyle changes.
Additionally, the many stresses of ongoing cancer treatment — adverse events, appointments with physicians and anxiety about outcomes — may cause patients to resort to familiar coping mechanisms.
According to Steinberg, patients are not the only ones who may harbor misconceptions and fatalism regarding smoking cessation after a cancer diagnosis. He said many providers may share these attitudes.
“There are a lot of physicians out there who might think, ‘Well, my patient was just diagnosed with lung cancer — they may as well just keep smoking,’ but there’s really nothing further from the truth,” he said. “From the provider and the patient standpoint, it’s really important that people understand the benefits of quitting smoking, whether you have cancer or are young and healthy.”
The body undergoes an immediate regenerative process after smoking cessation, Steinberg said. Within the first few hours of quitting, the body’s carbon monoxide levels and blood pressure decrease. Within the first few days to a week, pulmonary function improves and the risk for infection declines. Once the patient achieves months and years of nonsmoking, they begin to see bigger changes.
“Cardiovascular risk and cancer risk drop dramatically,” he said. “The benefits start immediately, and people start to feel better. Exercise tolerance improves, and the sense of smell and taste improve.”
Quitting: A comprehensive approach
Fortunately, patients with cancer have access to more smoking cessation tools and resources than ever before.
“The clinical practice guidelines suggest that the most effective treatment out there is a comprehensive approach that combines pharmacotherapy, behavioral treatment such as counseling, and follow-up and support,” Steinberg said. “That support could be within treatment, like a group treatment, or outside of treatment, like a network of friends and family who can be supportive.”
Over-the-counter medications for smoking cessation generally consist of nicotine replacement products, such as gum and patches. Additionally, two nicotine replacement treatments — a nasal spray and an oral inhaler — are available by prescription. Other prescription drugs, including varenicline (Chantix, Pfizer) and bupropion (Wellbutrin, GlaxoSmithKline), act on the brain through different mechanisms to reduce the urge to smoke.
According to a study conducted by researchers from Northwestern Medicine and Abramson Cancer Center at the University of Pennsylvania, the combination of counseling and a 24-week regimen of varenicline — vs. the standard 12-week regimen — improved the chances of success among patients with cancer trying to quit smoking. Additionally, the extended duration of varenicline treatment reduced the likelihood of relapse at 1 year.
These smoking cessation medications are appropriate for use by individuals with cancer, Steinberg said.
“The overwhelming majority of medications that we use for tobacco treatment don’t interact with other medications or treatments. They don’t have many side effects,” he said. “Sometimes, on a case-by-case basis, if people aren’t properly using nicotine replacement products, they can worsen nausea. But, if used properly, this usually doesn’t happen.”
Although clinicians have a clear directive to offer smoking cessation resources to patients with cancer, this conversation may be overlooked amid more pressing concerns, such as treatment decisions or follow-up evaluations.
However, Steinberg emphasized that the discussion about smoking doesn’t need to be an “all-or-nothing” prospect.
“The oncologists themselves do not have to be the ones who shoulder the burden of providing the [smoking cessation] treatment,” he said. “There are a lot of great treatment resources out in the community, and I think the oncologist’s role should be in identifying the tobacco user, advising them to quit and then referring them for appropriate treatment. They don’t have to get into an hourlong conversation about smoking.”
There is a substantial amount of observational data to suggest that patients with a healthy lifestyle are more likely to survive longer after a cancer diagnosis.
“Some studies have shown that weight gain after a breast cancer diagnosis is associated with an increased risk for breast cancer recurrence after completing breast cancer therapy,” Iyengar said. “One in six male cancer deaths and one in seven female cancer deaths are related to obesity, and this is alarming, because two-thirds of the U.S. population is overweight or obese.”
Still, no consensus has been reached in terms of specific, evidence-based nutritional guidelines for patients with cancer. However, Robien said much of the advice used for prevention also can be applied to patients living with cancer.
“All of our evidence seems to point to the same recommendations that we have to prevent cancer in the first place,” Robien said. “These are the recommendations of most professional and advocacy organizations, such as the American Cancer Society and the American Institute for Cancer Research, and most of us in the field would recommend that patients follow these recommendations.”
The American Institute for Cancer Research addresses the topic of weight in its guideline, according to Donald Abrams, MD, integrative oncologist at the University of California, San Francisco Osher Center for Integrative Medicine and general oncologist at Zuckerberg San Francisco General Hospital and Trauma Center.
“The No. 1 guideline is to keep your weight within the healthy range and to avoid weight gain in adult life,” he said.
Abrams said his recommendation is for patients to follow an organic, plant-based, antioxidant-rich, anti-inflammatory whole foods diet.
“I don’t think veganism or vegetarianism is the healthiest diet — I believe people need some animal protein and animal fat, particularly in terms of hormones,” he said. “I like deep cold water fish and organic poultry.”
Treatment response and survival outcomes are not the only considerations in formulating a healthy diet for these patients, experts said.
“For patients with cancer, we’ll want to consider what they’ll need to recover from the treatment,” Robien said. “People get things like mucositis, and their blood counts drop. We have to make sure they have all the nutrients they need to rebuild those healthy tissues.”
According to Robien, a registered dietitian with board certification in oncology nutrition, registered dietitians work with the medical team to support the patient in meeting nutritional needs and making healthy lifestyle changes. Registered dietitians typically have more time to devote to in-depth discussions with patients about nutrition than physicians would have.
“We tend to have at least half an hour, if not an hour, with each patient where we can really go through everything in detail — the patient’s type of cancer, the type of treatment, any side effects they might be having,” Robien said. “We can work with people to get them over the hump during treatment. As dietitians, we’re always listening to the patient and to the caregiver, finding out what’s working and what’s not.”
Oncology dietitians must consider the impact of cancer treatments on a patient’s ability to benefit from nutrition, Robien said.
“We refer to these as nutrition impact symptoms — the side effects of cancer treatments that impact a person’s ability to meet their nutritional needs,” she said. “Most of us have a little list of questions we keep in mind to ask the patient, like, ‘How are things tasting to you? How is chewing and swallowing going for you? Are you making enough saliva? Can you handle sticky foods? How can we sneak in a few extra calories here, some more protein there?’”
Dental problems are a nutrition impact symptom that patients might not anticipate when beginning cancer treatment, but they occur frequently, Robien said. High-dose radiation and chemotherapy can severely damage oral health, particularly among patients who have undergone bone marrow transplantation.
“When I was working as a dietitian at Fred Hutchinson Cancer Research Center, there was a team of dentists on staff; it was part of the pretreatment checkup that everyone saw a dentist,” she said. “Mucositis and decreased saliva production increase the risk for bacterial contamination in the mouth, loss of tooth structure, breakdown of teeth and loss of teeth. It affects what dietitians would recommend because it can affect what people are able to eat.”
Certain chemotherapy regimens also can interact with specific nutrients in a way that might diminish the potency of the treatment, Robien said. Oncology dietitians are mindful of any potential “drug-nutrient interactions.”
“For example, you want to avoid too much folate with an antifolate chemotherapy drug, so we can work with the medical team in that regard,” she said.
Impact of exercise
Exercise has been shown to improve quality of life after cancer diagnosis and observational data suggest that increased levels of physical activity are associated with improved survival outcomes.
A study presented at this year’s ASCO Annual Meeting found that patients with breast cancer achieved reductions in cancer-related fatigue and improved muscle strength through a combination aerobic walking/resistance band training regimen.
“Exercise can help improve a multitude of side effects associated with cancer therapies, such as fatigue, musculoskeletal pain, anxiety/depression and others,” Iyengar said.
He added that prospective randomized controlled trials are needed to definitively show anticancer efficacy of exercise interventions. Clinicians await the results of one such study, CHALLENGE, a phase 3 prospective study evaluating the impact of physical activity on DFS among patients with stage III colon cancer.
“Several trials have shown that exercise improves side effects linked to cancer treatment, but it is yet to be proven that lifestyle interventions prevent cancer recurrence and prolong survival,” he said. “Changing lifestyle habits such as diet and physical activity is incredibly difficult, and even more so for people receiving cancer therapy. This is one reason that the focus of lifestyle interventions has traditionally been in the preventive setting, where there is no active cancer therapy.”
Although exercise regimens should be developed based on the individual patient’s overall health and capabilities, a balance of aerobic and resistance exercise is beneficial for many patients, Abrams said.
“I try to get patients to do yoga, because it combines strength, balance and flexibility, as well as a mind-body intervention that I find useful,” he said. “Observational studies have shown that women with breast cancer who do the equivalent of 30 minutes of vigorous walking a week have improved outcomes, as do patients with colon cancer who do 60 minutes of walking a week.”
Iyengar said although he discusses lifestyle changes with his patients, he is careful not to make any claims that a healthy lifestyle can cure cancer.
“I can advise a patient that these lifestyle modifications can help with side effects and improve their cardiometabolic health, but I cannot definitively state that they will help with improving cancer outcomes,” he said, adding that his team is testing the anticancer effects of exercise and specific diet interventions in randomized control trials.
“Currently, we have several exercise and diet trials that are enrolling people diagnosed with cancer,” he added. “We are testing whether personalized exercise prescriptions or specific dietary patterns will amplify the effects of standard cancer therapies and slow tumor growth. For now, I can only bet that staying active and maintaining a healthy diet will improve cancer outcomes, and until we have more data to make specific recommendations, this is a bet I am willing to make.”
The integrative approach
Although many oncologists lack the time to devote to a comprehensive discussion about diet and exercise, the importance of these factors is widely acknowledged.
Referrals and multidisciplinary teams are two approaches to fill this potential care gap; a third approach, integrative medicine, puts the oncologist on the front line of this care.
“When I see a new patient at Osher Center for Integrative Medicine, I’m not their oncologist — I’m their integrative oncologist,” Abrams said. “I tell them that cancer is like a weed, and that other people are taking care of your weed; it’s my job to work with the garden. The goal is to make the soil as inhospitable as possible, so it doesn’t spread the weed.”
Abrams works with patients to develop a diet and exercise plan, establish their priorities, and discuss their progress along the way. The Osher clinic sometimes offers cooking show-style presentations, in which a chef makes healthy recipes and Abrams explains the benefits of these foods.
Abrams also incorporates spirituality and mindfulness into his cancer care.
“I ask them if they consider themselves spiritual,” he said. “Then I ask them three questions: ‘What brings you joy?’ ‘What are your hopes?’ and ‘Where does your strength come from?’”
These questions prompt patients to reflect on their goals, their coping skills and the meaning they derive from their experiences.
He recounted a conversation he had with a woman whose husband, also Abrams’ patient, had died a few years before.
“She told me, ‘Even though he was aware of where he was on his journey, when you asked him those questions, he realized suddenly that he did have joy, hope and strength. And that changed the whole rest of his life,’” Abrams said.
When discussing lifestyle changes with patients, Abrams’ one guiding principle is not to judge or guilt his patients.
“I tell patients all the time that I’m not the police, I’m not a priest; I’m just giving them my best recommendations,” he said. “You have to meet the patient where they are and figure out what works for them.” – by Jennifer Byrne
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For more information:
Donald Abrams, MD, can be reached at 1545 Divisadero St., 4th Floor, San Francisco, CA 94115; email: email@example.com.
Neil M. Iyengar, MD, can be reached at 300 E. 66th St., 8th Floor, New York, NY 10065; email: firstname.lastname@example.org.
Kim Robien, PhD, RD, CSO, FAND, can be reached at 950 New Hampshire Ave. NW, Washington, DC 20052; email: email@example.com.
Michael B. Steinberg, MD, MPH, FACP, can be reached at 125 Paterson St., Suite 2300, New Brunswick, NJ 08903; email: firstname.lastname@example.org.
Disclosures: Abrams, Iyengar, Robien and Steinberg report no relevant financial disclosures.