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

Abstract

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. 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. 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). 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.