Preoperative tumor marker burden score predicts survival in colorectal cancer according to tumor size.

BACKGROUND

Reliable preoperative biomarkers are needed to improve risk stratification in colorectal cancer (CRC). The prognostic value of a combined score based on multiple serum tumor markers remains underexplored.

METHODS

This retrospective study included 307 CRC patients undergoing curative surgery. A preoperative risk score was defined by the number of elevated markers (AFP, CA19-9, CA125, CA724, CA153) above institutional cut-offs. Patients were stratified into low-risk (≤ 1 elevated marker) and high-risk (> 1 elevated marker) groups. Associations with 5-year disease-free survival (DFS) and overall survival (OS) were analyzed using Kaplan-Meier and Cox regression. Subgroup analysis by tumor size (≤ 4 cm vs. >4 cm) was performed.

RESULTS

A low-risk score (≤ 1 elevated marker) was independently associated with improved 5-year OS (adjusted HR = 0.60, 95% CI: 0.37-0.97, P = 0.038) and showed a strong trend for better DFS (adjusted HR = 0.65, 95% CI: 0.42-1.00, P = 0.051) after adjusting for clinicopathological factors. Strikingly, this prognostic association was significant only in patients with tumors ≤ 4 cm (for OS: HR = 0.19, P = 0.003; for DFS: HR = 0.34, P = 0.010) but not in those with larger tumors (P > 0.05). The interaction between tumor size and the marker score on OS approached statistical significance (P for interaction = 0.051).

CONCLUSION

A simple preoperative multi-marker score is an independent prognostic factor for survival in CRC. Its predictive power is particularly strong in patients with smaller tumors (≤ 4 cm), suggesting a valuable role in refining preoperative risk assessment for this subgroup.