ABSTRACT
Background:Surgery-related muscle loss (SRML) occurs in at least one out of three cancer patients within one week after major surgery. Though, this important phenomenon has hardly been investigated.Methods:The MUSCLE POWERis a prospective, observational cohort study that investigates the presence, impact, and predictors for clinically relevant SRML in 178 cancer patients after major abdominal surgery using ultrasound measurements, squeeze and force measurements, and QoL questionnaires. Primary endpoint is the proportion of patients with clinically relevant SRML defined as ≥5% muscle loss within one week after surgery, measured by the cross-sectional area (CSA) of three different muscles:m. biceps brachii, m. rectus femoris, and m. vastus intermedius. Possible correlation with QoLand fatigue up to six months after surgery will be investigated. Daily physical activity during hospital stay will be monitored by a motility tracker, and protein intake will be monitored by a dietician. Possible predictors for clinically relevant SRML—consisting of age ≥65 years, preoperative diabetes, preoperative sarcopenia, major postoperative complications (Clavien-Dindo ≥III), insufficient physical activity, and insufficient postoperative protein intake—will be investigated with a multivariable logistic regression analyses with a backward stepwise approach. Variables with a p<0.05 will be retrained in the final multivariable model.Discussion: The MUSCLE POWERinvestigates the presence and impact of clinically relevant SRML in cancer patients after major abdominal surgery. Crucial information regarding possible predictors for clinically relevant SRML can be used in future intervention studies to prevent postoperative muscle loss and subsequently improve postoperative outcome and QoL.Trial Registration: Medical Ethics Committee of the University Medical Center Groningen, the Netherlands (METc2018/361, version 3.0, January 21, 2019), and Netherlands Trial Register ([NTR], NTR NL7505, version 1.0, February 7, 2019)