Abstract
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 <3.5 g/dL, and CRP >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<0.01). Multivariate analysis identified High C-GPS as an independent predictor of poor DFS (HR: 1.76, 95% CI: 1.01-3.10, p=0.049) and OS (HR: 1.30, 95% CI: 1.01-1.66, p=0.034). The C-GPS demonstrated superior prognostic discrimination compared to GPS for both DFS (C-index: 0.583 vs. 0.524) and OS (0.633 vs. 0.576). CONCLUSIONS: C-GPS is a simple and clinically feasible composite index that provides better prognostic accuracy than GPS by incorporating tumor burden, systemic inflammation, and nutritional status to stratify patients with CRC following curative surgery.