{
  "abstract": "Background Myosteatosis, defined by pathological fat infiltration within skeletal muscle, represents a pathophysiological hallmark of metabolic dysregulation and chronic inflammation alterations. Emerging evidence links this condition to adverse clinical outcomes across several malignancies.Aim To investigate the prognostic value of pretherapeutic myosteatosis in Tunisian patients with colorectal cancer.Methods A retrospective study including patients diagnosed with CRC between 2014 and 2022 was conducted. Pretherapeutic abdomino-pelvic computed tomography (CT) was performed in all patients. Muscle density was measured as the mean Hounsfield unit (HU) of the cross-sectional area of the left and right psoas muscles at the third lumbar vertebra level. Myosteatosis was defined as HU < 41 for patients with a body mass index (BMI) < 25 kg/m 2, and HU < 33 for patients with BMI ≥ 25 kg/m2. The Kaplan-Meier method was used to evaluate the impact of myosteatosis on overall survival.Results Seventy-eight patients were included, with a mean age of 60.6 ± 12.7 years and a sex ratio (M/F) of 1.89. The mean psoas muscle density was 34 ± 9.6 HU (range 14.1–53.2). Myosteatosis was diagnosed in 52% of patients (n=40) and was statistically associated with older age (p<0.001), female gender (p=0.01), lymphopenia (p=0.01), elevated platelet-to-lymphocyte ratio (p=0.003), and elevated carbohydrate antigen 19-9 levels (p = 0.005). Metastases were more frequent in patients with myosteatosis, approaching statistical significance (p = 0.05). In multivariate analysis, female gender (OR = 12.44; 95% CI [2.56–60.29]; p=0.008) was an independent factor associated with myosteatosis. Overall survival was significantly reduced in patients with myosteatosis (56 months vs. 89 months; log-rank p = 0.008). Survival analysis showed that myosteatosis was an independent predictor of mortality (OR = 5.7; 95% CI [1.3–23.54]; p=0.01).Conclusion Pretherapeutic myosteatosis is a frequent finding in patients with colorectal cancer and is strongly associated with adverse clinical and biological features. It independently predicts reduced overall survival, especially in female patients, highlighting its potential value as a prognostic imaging marker. Integrating muscle quality assessment into routine pretherapeutic assessment in patients with CRC may improve risk stratification and guide individualized management.",
  "authors": [
    {
      "affiliations": [
        "Internal Security Forces Hospital La Marsa, Tunis, Tunisia"
      ],
      "name": "Myriam Ayari"
    },
    {
      "affiliations": [
        "Internal Security Forces Hospital La Marsa, Tunis, Tunisia"
      ],
      "name": "Wafa Khemiri"
    },
    {
      "affiliations": [
        "Internal Security Forces Hospital La Marsa, Tunis, Tunisia"
      ],
      "name": "Sarra Ben Azouz"
    },
    {
      "affiliations": [
        "Internal Security Forces Hospital La Marsa, Tunis, Tunisia"
      ],
      "name": "Taieb Jomni"
    }
  ],
  "title": "P322 When muscle turns fatty: the prognostic significance of myosteatosis in colorectal cancer",
  "uid": "eb6e6b1a-b566-54d0-bb50-ea0d0bca4328"
}