Sarcopenia as a predictor of poor surgical and oncologic outcomes after abdominal surgery for digestive tract cancer: A prospective cohort study

Abstract

Sarcopenia has been widely recognized as an important predictor of poor outcomes in patients with cancer after surgery, but the controversy remains, and its impact on surgical and oncologic outcomes in patients after abdominal surgery for digestive tract cancer is poorly described. The aim of this study was to evaluate the prognostic impact of sarcopenia on surgical and oncologic outcomes in patients after abdominal surgery for digestive tract cancer. Six thousand four hundred and forty-seven consecutive patients who underwent abdominal surgery for digestive tract cancer in our institution were prospectively included. Sarcopenia was defined as skeletal muscle index below the lowest sex-specific quartile using computed tomography scan at L3 before surgery. The surgical and oncologic outcomes were recorded, and univariate and multivariate analyses were performed. Sarcopenia was present in 1638 of 6447 patients (25.4%) with digestive tract cancer before surgery based on the diagnostic cut-off values (43.13cm2/m2 for men and 37.81cm2/m2 for women). The incidence of postoperative total and pulmonary complications, and 30-day readmission were significantly higher in sarcopenic group than in nonsarcopenic group (37.4% vs 12.9%, P<0.001; 3.1% vs 2.1%, P=0.026; 1.1% vs 0.4%, P=0.003, respectively). The postoperative hospital stay was significantly longer in sarcopenic patients (9.42±3.40 vs 8.51±3.17 days, P<0.001). There were significantly more patients receiving postoperative chemotherapy or radiotherapy in sarcopenic group than in nonsarcopenic group (73.1% vs 69.2%, P=0.003; 10.6% vs 8.8%, P=0.038, respectively), and patients with sarcopenia had significantly more chemotherapy modifications including delay, dose reduction, or termination (48.5% vs 44.2%, P=0.018). In addition, during the follow-up period, sarcopenic patients had significantly lower rate of overall survival and disease-free survival than nonsarcopenic patients (53.9% vs 69.3%, P=0.002; 36.8% vs 59.7%, P=0.000, respectively). In multivariate analysis, sarcopenia was found to be a risk factor for postoperative complications [odds ratio (OR)=5.418, 95% confidence interval (CI)=2.986-9.828, P<0.001], and was an unfavorable prognostic factor for poor overall survival [hazard ratio (HR)=0.649, 95% CI=0.426-0.991, P=0.045] and disease-free survival (HR=0.514, 95% CI=0.348-0.757, P=0.001). Sarcopenia could be used as a strong and independent prognostic factor for poor surgical and oncologic outcomes in patients after abdominal surgery for digestive tract cancer. Identification of preoperative sarcopenia in digestive surgery for cancer and targeted approaches may improve its negative outcomes.