Aims
Declining physical function and skeletal muscle loss during chemotherapy are associated with poorer outcomes; however, proactive identification of patients at risk remains limited in routine oncology care. The PACER study aims to prospectively validate a risk-stratification pathway incorporating objective physical measures and behavioural capability to enable personalised supportive care during chemotherapy.
Methods
The Physical Activity during Chemotherapy to Enhance Recovery (PACER) pathway is a prospective cohort study embedded within routine care at a tertiary cancer centre. Adults commencing intravenous chemotherapy undergo baseline and monthly assessment of skeletal muscle mass using bioimpedance spectroscopy, physical performance using the Five Times Sit-to-Stand test, sarcopenia risk using SARC-F, and behavioural capability using the Cancer Behavioural Index-Brief (CBI-B). Screening results are used to categorise risk and guide targeted intervention, including exercise prescription, physiotherapy review, and multidisciplinary supportive care referral.
Exploratory analyses from the initial cohort investigated the association between baseline CBI-B scores and subsequent skeletal muscle outcomes.
Results
Early analysis of 100 participants demonstrated that higher CBI-B scores were associated with maintenance or gain of skeletal muscle mass. Participants maintaining or gaining muscle had significantly higher median CBI-B scores compared with those experiencing muscle loss (94 vs 81, p=0.0012), with a moderate effect size (rank-biserial correlation=0.376). ROC analysis demonstrated fair discrimination (AUC 0.688, 95% CI 0.585–0.791), with a preliminary threshold of 81 demonstrating high sensitivity (85.2%) for identifying participants maintaining or gaining muscle mass.
Conclusions
The PACER study is evaluating whether integrating behavioural capability with objective measures of muscle health and function can improve personalised supportive care during chemotherapy. Early findings suggest the CBI-B may provide additional value for identifying patients requiring early intervention. Prospective validation will determine the clinical utility of this multidimensional risk-stratification approach.