Thigh muscle assessed by CT images is an independent predictor of mortality in men with newly diagnosed colorectal cancer
Cancer; muscle mass; skeletal muscle radiodensity; skeletal muscle index; mortality; body composition
The aim of the study was to evaluate the prognostic value of thigh muscle assessed by CT-images to predict overall mortality in patients with colorectal cancer (CRC). This was a multicenter cohort study including adults (≥ 18 years old) newly diagnosed with CRC, who performed a diagnostic computed tomography (CT) exam including pelvic regions. CT images were analyzed to evaluate skeletal muscle mass (SM in cm²), skeletal muscle index (SMI in cm²/m²), and skeletal muscle density (SMD in HU). Muscle abnormalities (low SM, SMI, and SMD) were defined as the values below the median by sex. Kaplan-Meyer curves and hazard ratios (HRs) for low SM, SMI and SMD were evaluated for overall mortality, stratified by sex. A total of 257 patients were included in the final analysis. Patients’ mean age was 62.6 ± 12.1 years, and 50.2% (n = 129) were females. No statistically significant difference was observed in overall mortality between sexes. In males, low thigh SMI was associated with shorter survival (log-rank p = 0.021). Furthermore, this low thigh SMI (cm2/m2) was independently associated with higher mortality rates (HR 2.07, CI 95% 1.03; 4.17, p=0.041), even after adjusting for age, tumor site, and type of treatment. In contrast, none of the assessed thigh parameters showed a significant association with survival rates in females. Our findings show that low thigh SMI is associated with shorter overall survival in men with CRC