CHICAGO—Oncology nurses know that nutrition interventions can help their patients, both during and after active treatment. But the evidence is scant, and personalizing it for each patient can be a challenge. To help, nutrition experts provided useful tips for nurses, along with a discussion of the evidence.
Although a specialized dietitian can best help patients, oncology nurses are key partners in nutrition and physical activity interventions. Communication and coordination is essential, ideally with a nutrition consultation before treatment. Plus, successful counseling often requires multiple sessions, according to Kim Robien, PhD, RD, CSO, FADA. Nurses should, therefore, regularly apprise the dietitian of any changes in the patient’s health or treatment.
The Intervention
When designing the right nutrition intervention for the right patient, keep in mind the “3 general nutrition goals for a patient going through treatment,” said Robien, assistant professor in the Division of Epidemiology and Community Health, University of Minnesota, Masonic Cancer Center, Minneapolis, as she detailed her process.
Nutrition interventions should prevent nutrient deficiencies, maintain lean body mass (not to be confused with body weight), and minimize the impact of treatment-related side effects, she said. However, “the active treatment phase for most people is a time of coping, anxiety, and just getting through the treatments; and we need to be respective of that,” noted Robien. “It is not the time for us to be making major lifestyle changes… unless that helps with managing their side effects. It is small baby steps and helping them to make sure that they preserve lean body mass and prevent nutrient deficiencies.”
When developing a personalized nutrition plan, a specialist in oncology nutrition begins by taking baseline nutritional status. “Many of our patients come to us already nutrient depleted as a result of the cancer itself,” explained Robien, noting that, in addition, the number of patients with diet-manageable comorbid conditions, such as diabetes and hypertension, is on the rise. Next, the dietitian considers the planned treatment regimen, especially expected side effects, to help the patient and caregiver prepare to maintain nutritional status through those side effects.
Psychologic factors also come into play. A patient’s and/or caregiver’s goals for the nutritional intervention as well as for cancer treatment should be assessed, said Robien. “If choosing to [pursue the intervention] for palliative measures, we might not be as aggressive as someone who wants to continue as an Olympic athlete.” In addition, the dietitian evaluates the patient’s and caregiver’s readiness and motivation toward dietary change. “Some patients will come to lifestyle changes as their way of coping. It is something they understand. They may not understand medical terminology, they may not understand the planned treatment regimen, but they probably understand diet and physical activity; that may be their coping mechanism,” she explained. “Other patients just aren’t at that stage and need to get through cancer treatment before we do something more aggressive for them.”
What Is the Evidence?
Using the Institute of Medicine’s definition of survivorship, from diagnosis to end of life, Wendy Demark- Wahnefried, PhD, RD, professor and Webb Endowed Chair of nutrition sciences, University of Alabama at Birming ham, and associate director, University of Alabama at Birmingham Comprehensive Cancer Center, summarized the available evidence and guidelines (Sidebar).
Her literature review identified the level of evidence associating nutrition and physical activity with outcomes:
Although the evidence is sparse, she highlighted those studies that have associated diet and exercise with outcomes among cancer survivors. Kroenke and colleagues found that an increase in weight after breast cancer increases the risk for recurrence, disease-specific mortality, and all-cause mortality (J Clin Oncol. 2005;23:1370-1378). In addition, Meyerhardt and colleagues associated 1 hour per day of physical exercise with a decreased risk for recurrence, disease-specific mortality, and all-cause mortality among survivors of colorectal cancer (J Clin Oncol. 2006;24:3535-3541).
Other studies highlighted associated food choices with outcomes, but these studies failed to correlate outcomes directly with cancer diagnoses. For example, Kroenke and colleagues found that a prudent diet (avoidance of sugar and fat with an emphasis on plant-based sources) made no difference in breast cancer–specific mortality, but did make a significant impact on all-cause mortality (J Clin Oncol. 2005;23:9295-9303), an outcome Demark-Wahnefried noted was likely attributed to improved cardiac function. And Meyerhardt, in his study of colorectal cancer survivors, found similar survival outcomes, with a Western diet predisposing patients to all-cause mortality (JAMA. 2007;298:754-764).
Demark-Wahnefried highlighted still other studies that present conflicting data on the protective effect of diet on recurrence. Pierce and colleagues followed breast cancer survivors for up to 10 years, finding no difference in recurrence rates, disease-specific death rates, or overall death rates (JAMA. 2007;298: 289-298). These findings, Demark- Wahnefried noted, may have been caused by location bias. The California based study participants reported high consumption (≥7 servings per day) of fruits and vegetables at baseline. In their study, however, Chlebowski and colleagues found that reducing the fat consumption among breast cancer survivors did produce a protective effect, especially among estrogen receptor–negative women (J Natl Cancer Inst. 2006; 98:1767-1776). Because participants lost an average of 6 lb, Demark-Wahnefried noted that their outcomes may be attributable to a weight-loss phenomenon.
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