We designed the present work to explore the connection between sarcopenia and interleukin-16 (IL-16) expression and their integrated relation with gastric cancer (GC) survival. We deemed the sex-specific third lumbar vertebra skeletal muscle index cutoffs for sarcopenia to be ≤40.8 and ≤34.9 cm2/m2 in male and female patients, respectively. Immunohistochemistry was carried out to detect IL-16 levels among GC tissues of the patients. We determined overall survival (OS) and relapse-free survival (RFS) by univariate and multivariate analyses. This study included 225 GC cases, with an average age of 62.7 years. There were 41 (18.2%) female patients, and 107 (47.5%) patients had sarcopenia. Sarcopenia and high IL-16 expression were identified as independent factors to predict OS (hazard ratios [HR] = 1.64 and 1.79, 95% confidence interval [CI] = 1.25-2.23 and 1.16-2.78, respectively) and RFS (HR = 1.43 and 1.60, 95% CI = 1.15-2.95 and 1.10-2.37, respectively). There were more cases showing high IL-16 expression detected in the sarcopenia group (55.7% vs. 37.3%, p = 0.003). Later, we grouped the patients with sarcopenia and IL-16 expression and discovered that the patients with sarcopenia and IL-16 upregulation displayed the poorest OS (HR = 3.02; 95% CI = 1.64-5.91) and RFS (HR = 2.34; 95% CI = 1.47-4.69). In conclusion, more IL-16 upregulation was noted in GC patients with sarcopenia. Sarcopenia accompanied by high IL-16 expression remarkably indicates a dismal prognosis in GC patients. This suggests that these biomarkers may be able to identify patients with GC with poor prognosis and enhance prognostication.
Keywords: gastric cancer; inflammation; interleukin-16; sarcopenia.