Oral nutritional interventions can improve quality of life and overall nutritional intake in some cancer patients, but do not appear to have any effect on mortality outcomes, according to a meta-analysis published in the Journal of the National Cancer Institute.[1]
In a meta-analysis of 13 studies, nutritional supplements were shown to have a positive impact on patient quality of life“The study reminds us that nutritional support will not cure cancer, but it can have considerable benefits for patients’ quality of life. The importance of this should not be underestimated,” said the study’s senior author, Peter W. Emery, PhD, of King’s College London.
Dr. Emery and colleagues analyzed results of 13 previously published studies on nutritional interventions for cancer patients, involving a total of 1,414 patients considered malnourished or at risk for malnourishment. All studies compared routine care with an intervention—dietary advice, oral nutritional supplements, or the combination of both supplements and advice. There were a variety of cancer types represented, including gastrointestinal tumors, gynecological cancers, leukemia, lymphoma, and cancers of the bladder, lung, head and neck, and breast. All included patients were receiving treatment of some type.
The primary analysis of the interventions’ effect on mortality showed no significant difference. The relative risk of mortality for nutritional intervention patients vs. no intervention was 1.06 (P = .43).
There was improvement, however, in various measures of quality of life. Nutritional intervention resulted in significantly better scores related to emotional functioning, global quality of life, dyspnea, and loss of appetite. Intervention patients also showed improvement in nutritional intake and improvements in weight; the mean difference in weight was 1.86 kg (P = .02). When 2 studies responsible for the biggest variation were removed, however, there was no longer any difference in weight between intervention and routine care patients.
In an accompanying editorial, Ann O’Mara, PhD, RN, and Diane St. Germain, RN, stress the need to better understand the role of nutrition in cancer patients, noting that when malnutrition progresses to cachexia it accounts for as much as 30% of cancer-related deaths overall.[2] Still, the limitations of existing studies, and thus such a meta-analysis as Dr. Emery and colleagues conducted, are many. In particular, though some measures of quality of life were significantly better with nutritional intervention, the clinical importance of such improvements is not known. The substantial variation in the quality of included studies also makes interpretation and extrapolation difficult.
“Until future research provides clearer answers regarding who will benefit from nutritional interventions, the use of a comprehensive assessment, published nutritional guidelines, and early interventions are essential,” the editorial authors write.
Dr. Emery agrees that as of yet, the clinical utility of this research is not completely clear.
“I was a bit disappointed but not surprised at the lack of effect on mortality,” he says. “We still have a lot of work to do to define the situations in which nutritional support can make a difference to either morbidity or mortality in lots of different patient groups. But it is interesting that we are now beginning to be able to define some benefits that can make a real difference to patients’ lives.”
References
1. Baldwin C, Spiro A, Ahern R, et al. Oral Nutritional Interventions in Malnourished Patients With Cancer: A Systematic Review and Meta-Analysis. J Natl Cancer Inst. 2012;104:371-385.
2. O’Mara A and St. Germain D. Improved Outcomes in the Malnourished Patient: We’re Not There Yet. J Natl Cancer Inst. 2012;104:342-343.
