Validation of Skeletal Muscle Volume as a Nutritional Assessment in Patients With Gastric or Colorectal Cancer Before Radical Surgery

BACKGROUND Recently, some studies have reported the importance of sarcopenia as a prognostic factor in patients with gastrointestinal cancer who have undergone surgery. We aimed to examine skeletal muscle volume for use in nutritional assessment of preoperative patients, and to compare the results with those of other conventional methods of nutritional assessment, such as biochemical or body composition values. METHODS This was an open cohort study which examined skeletal muscle volume for use in nutritional assessment of preoperative patients. A total of 121 patients with gastrointestinal cancer who underwent radical surgery were enrolled in this study between June 1, 2008 and December 31, 2012. There were 39 and 82 patients with gastric and colorectal cancer, respectively. The primary outcome of this study was postoperative overall survival. The secondary outcomes were postoperative survival from cancer-related deaths, recurrences of cancer after surgery, postoperative complications, and postoperative hospital inpatient stay (measured in days). Univariate and multivariate analyses were used to identify the relevant factors for postoperative outcomes mentioned above. RESULTS Skeletal muscle volume was a significant (hazard ratio (HR): 3.34, 95% confidence interval (CI): 1.21 - 9.17, P = 0.020) independent prognostic factor for cancer-related deaths in patients with gastric or colorectal cancer who had undergone surgery, and a marginally independent (HR: 2.48, 95% CI: 0.91 - 6.81, P = 0.077) factor that negatively contributed to overall survival in these patients. In contrast, the preoperative skeletal muscle volume was not correlated with the recurrence of cancer, and was not significantly correlated with the occurrence of severe complications after surgery or prolongation of hospitalization. CONCLUSIONS The preoperative skeletal muscle volume was a significant prognostic factor in patients with gastric or colorectal cancers. Therefore, the estimation of skeletal muscle volume may be important for stable, long-term nutritional assessment in patients with gastrointestinal cancers.