Depletion of Essential Fatty Acids in Muscle Is Associated With Shorter Survival of Cancer Patients Undergoing Surgery

Background: Emerging studies are reporting associations between skeletal muscle abnormalities and survival in cancer patients. Cancer prognosis is associated with depletion of essential fatty acids in membrane of blood plasma and serum in humans, however the relationship between skeletal muscle membrane fatty acid composition and survival is unknown. This study investigates the relationship between fatty acid content of phospholipids in skeletal muscle and survival in cancer patients.Methods: Rectus abdominis biopsies were collected during cancer surgery from 35 patients diagnosed with cancer. Thin-layer and gas chromatography were used for quantification of phospholipid fatty acid content of the muscle. Cut-points for fatty acids were established using optimal stratification.Results: Median survival was between 450-500 days when patients had arachidonic acid (AA) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in muscle phospholipid above the cut-point compared to 720-800 days for patients below. Cox regression analysis revealed that low amounts of AA, EPA and DHA are risk factors for death. The risk of death remained significant for AA [HR 3.5 (1.11-10.87), p=0.03], EPA [HR 3.92 (1.1-14.0), p=0.04] and DHA [HR 4.08 (1.1-14.6), p=0.03] when adjusted for sex. Conclusion: Lower amount of essential fatty acids in skeletal muscle membrane is predictor of survival in cancer patients. These results warrant investigation to restore depletion of bioactive fatty acids in cancer.