Albumin-myosteatosis gauge as a prognostic biomarker in patients treated with immune checkpoint inhibitors.

2644 Background: Although immune checkpoint inhibitors (ICIs) have heralded a new era in cancer treatment, many patients do not respond, underscoring the need for biomarkers. The albumin-myosteatosis gauge (AMG) is a recently developed integrated measure of myosteatosis and serum albumin levels, reflecting systemic inflammation and malnutrition. Herein, we investigate the prognostic value of AMG in patients with advanced cancer treated with ICIs. Methods: A total of 308 patients with advanced cancer treated with ICIs were included. Skeletal muscle index (SMI) and skeletal muscle radiodensity (SMD) were measured from computed tomography images obtained at the level of the L3 vertebra. The AMG was calculated by multiplying SMD by albumin and expressed as an arbitrary unit (AU). Survival outcomes were assessed using Kaplan-Meier survival curves and Cox regression models. Results: The median age (interquartile range) was 63 (55-70), and 198 (64.3%) were male. Non-small cell lung cancer (NSCLC) was the most common primary cancer (28.2%), followed by renal cell carcinoma (RCC) (20.8%) and melanoma (20.2%). Regarding AMG, the cutoff values were determined to be 109.38 AU for males and 102.11 AU for females. Multivariable analyses revealed that lower AMG values were independently associated with decreased OS (HR: 1.43; 95% CI: 1.08-1.90; p=0.012) and PFS (HR: 1.39; 95% CI: 1.07-1.79; p=0.011) compared to the AMG high-group. Conclusions: Our findings suggest AMG, an easily accessible novel biomarker, is an independent prognostic factor for survival in patients with advanced cancer treated with ICIs. Prospective studies are required to validate these findings and evaluate the role of AMG measurement in aiding treatment choices.