Exploring potential predictors of low muscle mass and muscle loss in adults with cancer: A scoping review.

Abstract

Rationale: Early identification of cancer-related muscle loss is essential to enable timely interventions and mitigate adverse outcomes, including mortality. This scoping review aimed to identify predictors of cancer-related muscle loss, focussing on factors routinely assessed in clinical practice, to inform future screening and assessment efforts globally. Methods: Medline Complete, CINAHL Complete and Embase databases were screened up to October 2024. Studies were eligible if they investigated predictors of cancer-related muscle loss, included adults undergoing or previously treated for cancer, and assessed or estimated muscle mass. Results: The search identified 22,270 studies, 292 met the inclusion criteria. Studies most commonly included patients with upper and/or lower gastrointestinal cancers (47%), undergoing surgery (36%) or chemotherapy (27%). Most (65%) studies assessed muscle mass using computed tomography (CT) defined skeletal muscle mass at the third lumbar vertebra. Other methods included CT-defined single muscle mass (e.g., psoas) (15%), bioelectrical impedance analysis or spectrometry (12%), dual-energy x-ray absorptiometry (7%) or other (3%). As the benchmark for muscle mass assessment in oncology, results focused on CT-defined muscle loss, with comparison to other methods if findings differed. In total, 20 predictors of cancer-related muscle loss were identified. Twelve showed a consistent negative association with CT-defined muscle loss in uni- or multivariate analysis: age, lower BMI, performance status, body fat, physical function (e.g., gait speed), body weight, strength, energy intake, protein intake, arm or leg circumference, weight loss, and physical inactivity. In multivariate analysis alone: BMI, physical function and protein intake remained consistently negatively associated with CT-defined muscle loss. Conclusion: Valid screening tools for cancer-related muscle loss are currently lacking, but this review identified factors which may help identify patients at risk and requiring further assessment or timely referral for evidence-based nutrition and exercise treatment.