Maarten van Egmond

ABSTRACT Background and purpose: Decreased muscle mass and muscle strength are independent predictors of poor postoperative recovery in patients with esophageal cancer. If there is an association between muscle mass and muscle strength, physiotherapists are able to measure muscle strength as an early predictor for poor postoperative recovery due to decreased muscle mass. Therefore, in this cross-sectional study we aimed to investigate the association between muscle mass and muscle strength in predominantly older patients with esophageal cancer awaiting esophagectomy, prior to neoadjuvant chemoradiation. Methods: In patients with resectable esophageal cancer eligible for surgery between March 2012 and October 2015, we used computed tomography scans to assess muscle mass and compared them with muscle strength measures (handgrip strength, inspiratory- and expiratory muscle strength, 30-second chair stand test). We calculated Pearson correlation coefficients and determined associations with multivariate linear regression analysis. Results and discussion: A tertiary referral center referred 125 individuals to physiotherapy who were eligible for the study; we finally included 93 individuals for statistical analysis. Multiple backward regression analysis showed that gender (95% CI 2.05 to 33.82), weight (95% CI 0.39 to 1.02), age (95% CI (-0.91 to -0.04), left handgrip strength (95% CI 0.14 to 1.44) and inspiratory muscle strength (95% CI 0.08 to 0.38) were all independently associated with muscle surface area at L3. All these variables together explained 66% of the variability (R 2 ) in muscle surface area at L3 ( P < .01). Conclusions: This study shows an independent association between aspects of muscle strength and muscle mass in patients with esophageal cancer awaiting surgery and physiotherapists could use the results to predict muscle mass based on muscle strength in preoperative patients with esophageal cancer.