Sarcopenia is a bad harbinger of cancer-related survival in rectal cancer

Sarcopenia, characterized by the progressive loss of skeletal muscle mass and function, has been linked to poor oncological outcomes. This study aimed to assess the relationship between sarcopenia-defined through combined radiological and biochemical assessments-and survival outcomes in patients with rectal cancer.

Sarcopenia was evaluated using radiological measurements of skeletal muscle mass, visceral and subcutaneous fat tissue volumes, and biochemical parameters including albumin, protein, and Fib-4 index levels.

Deceased patients were older than survivors (mean 70 vs. 63years). Elevated Fib-4 scores (3.0-4.9) were mainly observed in non-operated patients with poor tumor regression. Post-treatment albumin levels were significantly higher in patients with complete response (42.0±3.5mg/dL) than in those with regression score-3 (37.3±8.7mg/dL) and non-operated patients (34.9±8.3mg/dL; p < 0.001). Pre-treatment skeletal muscle mass, subcutaneous fat, and visceral fat volumes were greater in survivors (22.3±7.0cm3 vs 19.2±7.0cm3, 27.7±20.3cm3 vs 18.7±14.0cm3 and 49.7±37.8cm3 vs 29.9±20.5cm3 respectively) than in deceased patients (p < 0.05). Larger tissue volumes-muscle≥16.95cm3, visceral fat≥39.35cm3, and subcutaneous fat≥17.65 cm3 were associated with longer overall survival. In univariate analysis, older age, low albumin, high Fib-4 index, and reduced tissue volumes predicted poorer survival, while multivariate analysis identified low post-treatment albumin as the only independent prognostic factor (HR 0.28, 95% CI:0.12-0.65, p = 0.003).

Sarcopenia is associated with decreased overall survival in rectal cancer. In patients receiving neoadjuvant therapy, lower volumes of muscle mass, subcutaneous fat, and visceral fat, together with lower albumin and protein levels and higher Fib-4 scores, may serve as predictive markers of sarcopenia.