Novel Preoperative Cancer-Specific Glasgow Prognostic Score Strongly Predicts Survival in Stage II/III Colorectal Cancer

Objectives: The Glasgow Prognostic Score (GPS), derived from serum C-reactive protein (CRP) and albumin (Alb) levels, is a validated prognostic marker in colorectal cancer (CRC). However, it lacks tumor-specific components. Carcinoembryonic antigen (CEA) is indicative of tumor burden and biology. To enhance prognostic stratification, we developed the Cancer-Specific Glasgow Prognostic Score (C-GPS), which integrates GPS with CEA. Methods: We retrospectively analyzed 753 patients with Stage II/III CRC who underwent curative resection between 2008 and 2018. The C-GPS was calculated by assigning one point each for CEA >5.0 ng/mL, Alb 1.0 mg/dL. Patients were categorized into Low (0), Mid (1-2), and High (3) C-GPS groups. Survival outcomes were evaluated using Kaplan-Meier and Cox regression models, and prognostic discrimination was assessed using the concordance index (C-index). Results: The 5-year disease-free survival (DFS) and overall survival (OS) rates were significantly lower in the High C-GPS group (62.1% and 72.7%, respectively; p