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Originally published as JCO Early Release 10.1200/JCO.2005.10.950 on January 31 2005 © 2005 American Society of Clinical Oncology.
Dietary Counseling Is Beneficial for the Patient With CancerDepartment of Family and Preventive Medicine, Cancer Prevention and Control Program, School of Medicine, University of California, San Diego, La Jolla, CA The maintenance of good nutritional status during initial treatments for cancer is generally recommended to increase the likelihood of successful completion of prescribed therapies, and possibly to promote improved quality of life during and after that phase of care.1 In cross-sectional studies, reduced intake and poor nutritional status have been observed to be correlated with poor outcome, but cause and effect cannot be assumed from such observations. Results of a randomized controlled study focused on colorectal cancer patients undergoing radiation therapy reported in this issue of the Journal of Clinical Oncology provide scientific evidence for the benefits of nutritional counseling in the management of these patients.2 The study confirms that individualized dietary counseling can promote the maintenance of adequate dietary intakes and body weight, resulting in a marked reduction in the incidence and severity of anorexia and diarrhea, and improved quality of life. Most notably, the beneficial effects observed in association with dietary counseling were generally maintained 3 months after the completion of radiation therapy. In this study, various effects of individualized dietary counseling focused on regular foods were compared with the effects of prescribing nutrient-dense, high-protein liquid dietary supplements or ad libitum intake in 111 colorectal cancer patients treated with radiation therapy. The prospective study design allows a comparison of the effects of intervention across the study arms over time, and several types of outcome variables were measured, including symptom severity, health-related quality of life, and nutritional status indicators. Another important characteristic of the study is the inclusion of a study arm that involved prescribing liquid dietary supplements, an approach that theoretically addresses the challenge of maintaining adequate intakes for these patients, but with less intensity or specificity than is achieved with dietary counseling. The randomization was stratified by stage; at baseline, malnutrition was evident only among the patients who had been diagnosed at more advanced stages of colorectal cancer. Measures that were conducted at baseline, at completion of prescribed radiation therapy, and 3 months thereafter included anthropometric measurements, an index of nutritional status based on a multicomponent assessment tool, a detailed dietary history, the presence and degree of symptoms related to radiation therapy (such as anorexia, nausea and vomiting, and diarrhea), and health-related quality of life. The latter was assessed with an established cancer-specific questionnaire that included queries relating to various functions such as physical, cognitive, social, symptoms, and other potential negative results of the disease or condition. The goal of nutrition intervention, in both the dietary counseling and supplement study arms, was to enable the patient to meet the estimated requirements for intakes of energy, protein, and other nutrients, determined by standard calculations. After completion of the prescribed radiation therapy, both the dietary counseling group and the liquid dietary supplement group exhibited an increase in energy intake (averaging an increase of 555 and 296 kcal/d, respectively), whereas the ad lib group reported a decline in energy intake (averaging –285 kcal/d). At 3 months postradiation therapy, the counseling group maintained their intakes, while both of the other groups exhibited a decline at that time point. As a result of these intakes, the patients determined to be malnourished at baseline in the dietary counseling group actually recovered an average 4 kg of body weight at the 3-month follow-up time point. After radiation therapy, only three of 37 patients in the dietary counseling group exhibited a decline from baseline in nutritional status, compared with 19 of 37 patients in the liquid supplement group and 34 of 37 patients in the ad libitum group. In association with good dietary intakes and nutritional status, the dietary counseling group also exhibited the lowest symptom severity score, with lower incidence rates of anorexia and diarrhea, and much lower likelihood of needing antiemetic or antidiarrheal medications during and after radiation therapy. Furthermore, quality-of-life function scores improved proportionally with adequate intakes and nutritional status, which was most evident and was maintained at 3 months postradiation therapy in the counseling group. What are the elements of a good dietary counseling intervention that may explain the sustained behavior and associated beneficial effects that were observed in the study? As concisely described by the authors, the therapeutic dietary recommendations and guidance with food choices were individualized on the basis of personal characteristics, including the anticipated digestive and absorptive capacity, the presence of various symptoms, psychological factors, and personal eating patterns and preference. Meal plans with details regarding specific foods, amounts, and frequency of eating were provided, as would be appropriate with an individualized approach. These elements of individualized dietary counseling also have been proven useful in other conditions in which change in dietary behavior is the target, such as the prevention and management of diabetes and hypertension, and in cancer prevention and control.3-8 For clinicians, this type of nutrition intervention is generally available for their patients by referral to a registered dietitian. Knowledge of food content and nutritional science, combined with counseling skills focused on diet-related behavior, can facilitate changes in that behavior. As suggested by the results of this study and others that have used individualized dietary counseling, this approach has a greater likelihood of continued benefit when compared with nonspecific prescriptive approaches that do not take personal characteristics and preferences into consideration. The study by Ravasco et al2 specifically tested the effect of dietary counseling in patients with colorectal cancer who were undergoing radiation therapy, a circumstance in which there is high risk for unwanted weight loss and adverse gastrointestinal effects that may make meeting nutritional requirements a challenge. Notably, there is considerable variability in the risk for malnutrition after the diagnosis of cancer, across the various cancer types and subgroups of the population. In contrast with the particular target group in this study, for example, women diagnosed with breast cancer often gain, rather than lose, weight during the initial treatments.9 For breast cancer survivors, the focus of dietary and lifestyle intervention is generally to promote healthy weight management and a moderate rate of weight loss in the overweight or obese patient through modified intakes and increased physical activity.1,10 Nutrition can play an important role in the management of the cancer patient, across the spectrum from the initial phases of treatment and recovery through the long-term continuum of care in which the goals are to prevent recurrence, to reduce risk for comorbid disease, and to increase likelihood of survival. Individuals who have been diagnosed with cancer are often motivated to modify their diets and seek nutritional guidance.1,11 Food choices and eating patterns are one aspect of life over which the patient has some control, and these are modifiable factors. Evidence from the study by Ravasco et al2 suggests that individualized dietary counseling can be successful in enabling patients at high risk of deterioration in nutritional status to maintain good status, which is accompanied by a reduction in symptoms and improved health-related quality of life. Whether dietary counseling in other target groups across the cancer continuum can alter outcomes is being addressed in ongoing studies,8,10 and continued research efforts in this area are anticipated. Author’s Disclosures of Potential Conflicts of Interest The author indicated no potential conflicts of interest. REFERENCES
1. Brown JK, Byers T, Doyle C, et al: Nutrition and physical activity during and after cancer treatment: An American Cancer Society guide for informed choices. CA Cancer J Clin 53:268-291, 2003
2. Ravasco R, Monteiro-Grillo I, Vidal PM, et al: Dietary counseling improves patient outcomes: A prospective, randomized, controlled trial in colorectal cancer patients undergoing radiotherapy. J Clin Oncol 23:1431-1438, 2005
3. Diabetes Prevention Program Research Group: Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med 346:393-403, 2002 4. Smith DE, Heckemeyer CM, Kratt PP, et al: Motivational interviewing to improve adherence to a behavioral weight-control program for older obese women with NIDDM: A pilot study. Diabetes Care 20:52-54, 1997[Abstract]
5. Writing Group of the PREMIER Collaborative Research Group: Effects of comprehensive lifestyle modification on blood pressure control. JAMA 289:2083-2093, 2003 6. Women’s Health Initiative Study Group: Dietary adherence in the Women’s Health Initiative Dietary Modification Trial. J Am Diet Assoc 104:654-658, 2004[CrossRef][Medline] 7. Rock CL, Moskowitz A, Huizar B, et al: High vegetable and fruit diet intervention in premenopausal women with cervical intraepithelial neoplasia. J Am Diet Assoc 101:1167-1174, 2001[CrossRef][Medline]
8. Pierce JP, Newman VA, Flatt SW, et al: Telephone counseling intervention significantly increases intakes of micronutrient- and phytochemical-rich vegetables, fruit and fiber in breast cancer survivors. J Nutr 134:452-458, 2004 9. Rock CL, Flatt SW, Newman V, et al: Factors associated with weight gain in women after diagnosis of breast cancer. J Am Diet Assoc 99:1212-1218, 1999[CrossRef][Medline]
10. Rock CL, Demark-Wahnefried W: Can lifestyle modification increase survival in women diagnosed with breast cancer? J Nutr 132:3504S-3509S, 2002 11. Rock CL: Diet and breast cancer: Can dietary factors increase survival? J Mammary Gland Biol Neoplasia 8:119-132, 2003[CrossRef][Medline]
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Copyright © 2005 by the American Society of Clinical Oncology, Online ISSN: 1527-7755. Print ISSN: 0732-183X
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