Energy expenditure in upper gastrointestinal cancer: A scoping review

Aims: Cancer-associated malnutrition is associated with shorter survival and poor quality of life, and is prevalent in people with upper gastrointestinal (GI) cancers. Effective nutrition interventions providing adequate energy to meet metabolic demand are needed to prevent or treat malnutrition. In practice, energy needs of people with cancer are often estimated from predictive equations known to be inaccurate in the cancer population. The purpose of this scoping review was to synthesise the existing evidence regarding energy expenditure in people with upper GI cancer.
Methods: A systematic search was conducted across three databases (Ovid MEDLINE, Embase via Ovid, CINAHL plus) to identify studies using reference methods to measure resting energy expenditure (REE) using indirect calorimetry, and total energy expenditure (TEE) using doubly labelled water (DLW), in adults with any stage of upper GI cancer, at any point from diagnosis.
Results: Fifty-seven original research studies were eligible for inclusion, involving 2,125 individuals with cancer of the oesophagus, stomach, pancreas, biliary tract or liver. All studies used indirect calorimetry to measure REE, and one study also used DLW to measure TEE. Energy expenditure was unadjusted in 42 studies, adjusted for body weight in 32 studies, and adjusted for fat-free mass in 13 studies. Energy expenditure was compared to non-cancer controls in 19 studies, and measured vs. predicted energy expenditure was reported 31 studies. There was between-study heterogeneity in study design and in reporting of important clinical characteristics. There was also substantial variation in energy expenditure between studies, and within and between cancer types.
Conclusions: Energy expenditure should be measured in practice wherever feasible, given the heterogeneity of results summarised in this review and known inaccuracies of predictive equations in patients with cancer. Additional research in cohorts defined by cancer type, stage and treatment is needed to further characterise energy expenditure in upper GI cancer.