Inclusion of Sarcopenia Outperforms the Modified Frailty Index in Predicting 1-Year Mortality among 1,326 Patients Undergoing Gastrointestinal Surgery for a Malignant Indication

BACKGROUND: Although it is a useful metric for preoperative risk stratification, frailty can be difficult to identify in patients before surgery. We sought to develop a preoperative frailty-risk model combining sarcopenia with clinical parameters to predict 1-year mortality using a cohort of patients undergoing gastrointestinal cancer surgery. STUDY DESIGN: We identified 1,326 patients undergoing hepatobiliary, pancreatic, or colorectal surgery between 2011 and 2014. Sarcopenia defined by psoas density was measured using preoperative cross-sectional imaging. Multivariable Cox regression analysis was performed to identify preoperative risk factors associated with 1-year mortality and used to develop a preoperative risk-stratification score. RESULTS: Among all patients identified, 640 (48.3%) patients underwent pancreatic surgery, 347 (26.2%) underwent a hepatobiliary procedure, and 339 (25.5%) a colorectal procedure. Using sex-specific cut-offs, 398 (30.0%) patients were categorized as sarcopenic. Sarcopenic patients were more likely to develop postoperative complications vs non-sarcopenic patients (odds ratio [OR] 1.80, 95% CI 1.42 to 2.29; p < 0.001). Overall 1-year mortality was 9.4%. On multivariable analysis, independent risk factors for 1-year mortality included increasing age (65 to 75 years: [hazard ratio (HR) 1.81, 95% CI 1.05 to 3.14] greater than 75 years [HR 2.79, 95% CI 1.55 to 5.02]), preoperative anemia hemoglobin < 12.5 g/dL (HR 1.68, 95% CI 1.17 to 2.40), and preoperative sarcopenia (HR 1.98, 95% CI 1.36 to 2.88; all p < 0.05). Using these variables, a 28-point weighed composite score was able to stratify patients by their risk for mortality 1 year after surgery (C-statistic = 0.70). The proposed score outperformed other indices of frailty including the modified Frailty Index (C-statistic = 0.55) and the Eastern Cooperative Oncology Group (ECOG) performance score (C-statistic = 0.57) (both p < 0.05). CONCLUSION: Sarcopenia was combined with clinical factors to generate a composite risk-score that can be used to identify frail patients at greatest risk for 1-year mortality after gastrointestinal cancer surgery. (J Am Coll Surg 2016; 222: 397-409. (C) 2016 by the American College of Surgeons. Published by Elsevier Inc. All rights reserved.)