Impact of sarcopenia and visceral fat on postoperative morbidity and survival after rectal cancer surgery in patients treated with neoadjuvant chemoradiotherapy

Abstract

BackgroundThe aim of this study was to assess the impact of sarcopenia, increased visceral fat and skeletal muscle loss on short-term outcomes and survival in patients undergoing neoadjuvant treatment followed by surgery for locally advanced rectal cancer. MethodsBetween 2008 and 2019, 100 patients with available baseline CT scan data at our institution were retrospectively analyzed. Body composition parameters were measured, including skeletal mass index (SMI), baseline sarcopenia, visceral fat area, subcutaneous fat area, visceral-to-subcutaneous ratio, visceral obesity, waist circumference and abdominal obesity. When CT scan after neoadjuvant therapy was available, evolution of skeletal muscle mass was calculated. ResultsThe prevalence of sarcopenia was 43% at baseline, and 53% after neoadjuvant treatment. During neoadjuvant treatment, 41% of patients lost ≥ 5% of skeletal muscle mass. No body composition parameter was associated with increased 30-day postoperative morbidity or occurrence of anastomotic leakage. Baseline sarcopenia and abdominal obesity significantly increased length of hospital stay and 90-day postoperative morbidity. Patients with baseline sarcopenia had a significantly lower 3-year disease-free survival (59% vs. 75%, p=0.041). In multivariate analysis, two variables adversely affected disease free survival: presence of baseline sarcopenia (HR=3.02; 95%CI: 1.23-7.43; p=0.016) and ypN+ stage (HR=2.95; 95%CI: 1.14-7.63; p=0.026). Loss of skeletal muscle mass during neoadjuvant treatment had no influence on short-term outcomes and survival. ConclusionsBaseline sarcopenia is associated with longer length of hospital stay, increased medium-term postoperative morbidity and worse survival in patients with locally advanced rectal cancer treated with neoadjuvant treatment. This parameter should be actively researched and corrected in order to improve management of these patients.