Impact of preoperative muscle mass deficit and myosteatosis on postoperative short-term outcomes after esophageal or pancreatic cancer surgery

INTRODUCTION: Esophagectomy and pancreatectomy are invasive oncological surgeries with elevated mortality rates. Preoperative muscle mass deficit and myosteatosis, identifiable on L3 CT-scan, could be associated with poor postoperative outcomes in cancer patients. We aimed to determine their impact on short-term complications following esophageal or pancreatic cancer resection. METHODS: We conducted a retrospective cohort study in two hospital centers from January 2018 to February 2023. Adult patients undergoing esophagectomy or pancreatectomy for cancer with a preoperative CT scan at L3 level were included. Muscle skeletal mass and quality were assessed using previously published thresholds. Poor postoperative short-term outcomes were defined as the occurrence of sepsis, septic shock, or death within 90 days postoperatively. RESULTS: Of 216 patients, 165 patients were eligible for muscle mass analysis and 143 for muscle quality assessment. Poor short outcome occurred in 55 patients (33.3%). Surprisingly, skeletal muscle depletion was inversely associated with poor outcomes in the multivariate logistic regression model (OR 0.38, 95% CI [0.15-0.97], p=0.04). Myosteatosis was associated with a significantly 6-fold increased risk of poor short-term outcomes in univariate analysis (OR 6.04, 95% CI [2.35-15.55], p<0.001), with a persistent trend in the multivariate logistic regression model (OR 3.51, 95% CI [0.99-12.39], p=0.05). In the ICU subgroup, patients with preoperative skeletal muscle depletion and myosteatosis had higher 28-day mortality than those with preserved muscle mass and quality. CONCLUSION: Myosteatosis, rather than muscle mass deficit, showed a strong trend toward association with adverse postoperative short-term outcomes following esophagectomy and pancreatectomy. Defining population-specific thresholds for CT scan muscle assessment are necessary to improve the use of L3 scans for short-term outcome risk evaluation in oncologic surgery.