The effect of oral omega-3 polyunsaturated fatty acid supplementation on muscle maintenance and quality of life in patients with cancer: A systematic review and meta-analysis.

BACKGROUND & AIMS: Omega-3 polyunsaturated fatty acid (PUFA) supplementation has been proposed as a potential therapy for cancer-related malnutrition, which affects up to 70% of patients with cancer. The aim of this systematic review and meta-analysis was to examine the effects of oral omega-3 PUFA supplementation on muscle maintenance, quality of life, body weight and treatment-related toxicities in patients with cancer. METHODS: Randomised controlled trials in patients with cancer aged ≥18 years were retrieved from 5 electronic databases: MEDLINE (via PubMed), EMBASE, CENTRAL, CINAHL (via EBSCOhost), and Web of Science, from database inception until 31st of December 2019. The quality of included studies was assessed using the Cochrane risk of bias tool. Trials supplementing ≥600 mg/d omega-3 PUFA (oral capsules, pure fish oil or oral nutritional supplements) compared with a control intervention for ≥3 weeks were included. Meta-analyses were performed in RevMan to determine the mean differences (MD) in muscle mass, quality of life and body weight, and odds ratio (OR) for the incidence of treatment-related toxicities between omega-3 PUFA and control groups with 95% confidence intervals (CI) and I2 for heterogeneity. RESULTS: We included 31 publications in patients with various types of cancers and degrees of malnutrition. The Cochrane risk of bias tool graded most trials as 'unclear' or 'high' risk of bias. Meta-analyses showed no significant difference between omega-3 PUFA supplements and control intervention on muscle mass, quality of life and body weight. Oral omega-3 PUFA supplements reduced the likelihood of developing chemotherapy-induced peripheral neuropathy (OR: 0.20; 95% CI: 0.10-0.40; p < 0.001; I2 = 0%). CONCLUSION: This systematic review and meta-analysis indicates that oral omega-3 PUFA supplementation does not improve muscle maintenance, quality of life or body weight in patients with cancer, but may reduce the incidence of chemotherapy-induced peripheral neuropathy. Well-designed large-scale randomised controlled trials in homogenous patient cohorts are required to confirm these findings.

Nutritional counseling and nutritional supplements: a cornerstone of multidisciplinary cancer care for cachectic patients.

PURPOSE OF REVIEW: The challenge with cancer cachexia is that it is not fully reversed by nutrition support. The purpose of this review is to provide an opinion on the nutritional management of cancer cachexia based on the most recent available evidence. RECENT FINDINGS: There continues to be a paucity of nutrition intervention studies in patients with cancer cachexia. In patients with cancer undergoing radiotherapy, there is strong evidence that nutrition counseling increases dietary intake, body weight, nutritional status and quality of life with some suggestion that dietary counseling may improve nutrition impact symptoms, treatment response and survival. In patients with cancer undergoing chemotherapy, the evidence is less clear. The use of n-3 polyunsaturated fatty acids may have some positive effects in patients with cancer; however, clinical judgment and care need to be taken in its application. Preliminary results of studies in the use of L-carnitine in improving fatigue are promising; however, the largest trial in 'healthy' cancer patients showed no benefit. SUMMARY: Further research into the most appropriate methods for identifying and treating cancer cachexia is required. Regardless of whether patients are experiencing reduced dietary intake resulting in malnutrition or due to cachexia, nutrition remains a cornerstone of multimodal treatment.

Clinical outcomes of vitamin D deficiency and supplementation in cancer patients.

Results of recent studies suggest that circulating levels of vitamin D may play an important role in cancer-specific outcomes. The present systematic review was undertaken to determine the prevalence of vitamin D deficiency (<25 nmol/L) and insufficiency (25-50 nmol/L) in cancer patients and to evaluate the association between circulating calcidiol (the indicator of vitamin D status) and clinical outcomes. A systematic search of original, peer-reviewed studies on calcidiol at cancer diagnosis, and throughout treatment and survival, was conducted yielding 4,706 studies. A total of 37 studies met the inclusion criteria for this review. Reported mean blood calcidiol levels ranged from 24.7 to 87.4 nmol/L, with up to 31% of patients identified as deficient and 67% as insufficient. The efficacy of cholecalciferol supplementation for raising the concentration of circulating calcidiol is unclear; standard supplement regimens of <1,000 IU D3 /day may not be sufficient to maintain adequate concentrations or prevent decreasing calcidiol. Dose-response studies linking vitamin D status to musculoskeletal and survival outcomes in cancer patients are lacking.