Predicting colorectal cancer survival by combined c-reactive protein and tumor immune score

We evaluated the joint relationship of post-operative C-reactive protein (poCRP) and a tumor immune-cell-score (IS) with overall survival (OS) and CRC-specific survival (CSS) in 680 colorectal cancer (CRC) patients recruited in Germany. CRP was assessed post-surgery while IS was derived from CD3 + /CD8+ cell densities in tumor tissue. Patients were categorized into four C-Reactive protein-Immune cell Score (CRIS) groups: CRIS-1 (CRP-low/IS-high), CRIS-2 (CRP-low/IS-low), CRIS-3 (CRP-high/IS-high), and CRIS-4 (CRP-high/IS-low). Associations of CRIS with survival were assessed using Cox regression, and quantified by hazard ratios with 95% confidence intervals (HR, 95%CI). Subgroup analysis by presence of non-metastatic disease and time of blood draw in relation to adjuvant chemotherapy were conducted. After a median follow-up of 9.6 (IQR, 4.6-14.6) years, 214 (31.5%) patients died, 140 (20.6%) from CRC. Patients in CRIS-4 category had worse prognosis compared to CRIS-1 category [HR_(95%CI): 2.01 (1.32-3.08) and 2.60 (1.57-4.32) for OS and CSS, respectively]. These associations were stronger for non-metastatic disease (OS_HR = 2.45, CSS_HR = 4.49), as well as for patients with blood collected after adjuvant chemotherapy (OS_HR = 4.17, CSS_HR = 6.62). Integrating post-operative systemic inflammation and tumor immune characteristics may improve prognostic stratification of patients receiving adjuvant chemotherapy for non-metastatic CRC.