Nutritional counseling for patients with incurable cancer: Systematic review and meta-analysis

Background & aims: This systematic review aims to determine whether nutritional counseling by registered dietitians and/or nutritional specialists is recommended for adult patients with incurable advanced or recurrent cancer who are refractory to or intolerant of anticancer therapy.

Methods: This systematic review analyzed randomized controlled trials (RCTs) of nutritional counseling in cancer patients older than 18 years, primarily those with stage 4 cancer. Nutrition counseling was performed by registered dietitians and/or nutritional specialists using any method, including group sessions, telephone consultations, written materials, and web-based approaches. We searched the Medline (PubMed), Medline (OVID), EMBASE (OVID), CENTRAL, Emcare, and Web of Science Core Collection databases for articles published from 1981 to 2020. Two independent authors assessed the risk of bias used the Cochrane Risk of Bias 2 tool. Meta-analysis was performed for results and outcomes that allowed quantitative integration. This systematic review protocol was registered with the International Prospective Register of Systematic Reviews (ID: CRD42021288476) and registered in 2021.

Results: The search yielded 2376 studies, of which 7 assessed 924 patients with cancer aged 24-95 years. Our primary outcome of quality of life (QoL) was reported in 6 studies, 2 of which showed improvement with nutritional counseling. Our other primary outcome of physical symptoms was reported in two studies, one of which showed improvement with nutritional counseling. Quantitative integration of both QoL and physical symptoms was difficult. A meta-analysis of energy and protein intake and body weight was performed for secondary outcomes. Results showed that nutrition counseling increased energy and protein intake, but total certainty of evidence (CE) was low. Bodyweight was not improved by nutrition counseling.

Conclusions: Nutrition counseling is shown to improve energy and protein intake in patients with incurable cancer. Although neither nutrient intake can be strongly recommended because of low CE, nutrition counseling is a noninvasive treatment strategy that should be introduced early for nutrition intervention for patients with cancer. This review did not find sufficient evidence for the effect of nutrition counseling on QoL, a patient-reported outcome. Overall, low-quality and limited evidence was identified regarding the impact of nutrition counseling for patients with cancer, and further research is needed.