Background: Current evidence suggests that there may be an association between low skeletal muscle mass (SMM) and poor health-related quality of life (HRQOL) in people with cancer. However, the failure of studies to account for factors such as nutrition status or prior cancer treatment in their analyses limits the interpretation of this relationship, as both are potential confounders. This study sought to control for these variables in an examination of the association between SMM and HRQOL, in a cohort of upper gastrointestinal cancer patients.
Methods: A prospective cross-sectional study was conducted using baseline data of participants enrolled in a randomised controlled trial at diagnosis of oesophageal, gastric or pancreatic cancer between 2017 and 2019. Data collected prior to commencement of cancer treatment included: SMM derived from analysis of diagnostic computed tomography (CT) imaging, nutrition risk (PG-SGA short form), and HRQOL (EORTC-QLQ C30). Low SMM was identified using sex-specific thresholds1. Correlations between these variables, and contributors to variation in HRQOL using linear regression, were examined.
Results: The study included 105 treatment-naive patients with oesophageal (43%), gastric (20%), or pancreatic (37%) cancers. The cohort was 68% male, mean age 65.9 (SD±10.0) years. At diagnosis, 56% of patients had low SMM, and 49% had a high nutrition risk score (PG-SGA short form score ≥ 9). SMM was weakly, negatively correlated with nutrition risk score (r= -0.268, p=0.006), and physical, role and summary HRQOL scores (all p<0.05). In multivariate analyses, SMM was not significantly associated with any measure of HRQOL. Higher nutrition risk scores were an independent contributor to reduction in every examined HRQOL scale.
Conclusion: Nutrition risk is a stronger predictor of HRQOL than SMM, and should be included as a covariate in future studies investigating HRQOL in people with cancer.