Post-chemotherapy C-reactive protein/albumin ratio predicts prognosis in stage II-III colorectal cancer

Abstract

Background: Colorectal cancer (CRC) is a leading cause of cancer-related mortality worldwide. The C-reactive protein/albumin ratio (CAR) has emerged as a potential prognostic marker in various cancers. Nonetheless, if the post-surgical drug therapy CAR is a beneficial predictive component in individuals with CRC remains unclear.

Aim: To investigate the prognostic value of post-adjuvant chemotherapy CAR in comparison with preoperative CAR and other inflammatory markers in patients with stage II-III CRC.

Methods: This retrospective study included 445 patients with CRC that experienced anti-cancer therapy subsequent to definitive excision. Pre-surgical and post-adjuvant therapeutic regimen CAR, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII) were calculated to assess the inflammatory state of the patients. First, patients were divided into two groups based on the CAR, NLR, PLR, and SII values. Furthermore, patients were partitioned into four clusters for every parameter based on the long-term variations in measures from before surgery to after chemotherapy: Low, normalized, high, and elevated groups. Multiple studies concerning overall survival (OS) were executed to compensate for well-documented clinicopathological factors. Kaplan-Meier method and Cox regression approaches were applied to evaluate distinct predictive factor.

Results: Post-adjuvant chemotherapy CAR demonstrated the highest area under the curve value (0.8175) among all inflammatory markers for predicting OS. Post-adjuvant chemotherapy inflammatory markers (CAR, NLR, PLR, and SII) showed significantly higher area under the curve values than their preoperative counterparts. Longitudinal analysis revealed that a reduced inflammatory cohort exhibited markedly superior OS than an elevated inflammatory cohort regarding every indicator (all P < 0.0001). The normalized group (high preoperatively but low post-chemotherapy) exhibited notably inferior outlook than the consistently reduced population for CAR (P = 0.0002) and SII (P = 0.0002).

Conclusion: These results indicate that post-adjuvant chemotherapy CAR is superior to preoperative measurements and other systemic inflammation-based prognostic scores in predicting outcomes for patients with stage II-III CRC. Longitudinal monitoring of inflammatory markers, particularly CAR, provides valuable prognostic information and may guide clinical decision-making in the post-treatment surveillance period.

Keywords: C-reactive protein/albumin ratio; Neutrophil-to-lymphocyte ratio; Platelet-to-lymphocyte ratio; Post-adjuvant chemotherapy; Prognostic scores; Systemic immune-inflammation index.

Figure 1

Study design and flowchart.

Figure 2

Receiver operating characteristic curve analysis to evaluate the predictive value of each inflammatory biomarker for overall survival in all recruited patients with colorectal cancer. A: C-reactive protein/albumin ratio; B: Neutrophil-to-lymphocyte ratio; C: Platelet-to-lymphocyte ratio; D: Systemic immune-inflammation index. CAR: C-reactive protein/albumin ratio; NLR: Neutrophil-to-lymphocyte ratio; PLR: Platelet-to-lymphocyte ratio; SII: Systemic immune-inflammation index; AUC: Area under the curve.

Figure 3

Overall survival curves for patients with stage IIB-IIIC colorectal cancer by an inflammation-based prognostic marker at the preoperative and adjuvant chemotherapy time points (n = 445). Patients were stratified into two groups by C-reactive protein/albumin ratio (CAR), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII). A: Preoperative CAR; B: Adjuvant chemotherapy CAR; C: Preoperative NLR; D: Adjuvant chemotherapy NLR; E: Preoperative PLR; F: Adjuvant chemotherapy PLR; G: Preoperative SII; H: Adjuvant chemotherapy SII. CAR: C-reactive protein/albumin ratio; NLR: Neutrophil-to-lymphocyte ratio; PLR: Platelet-to-lymphocyte ratio; SII: Systemic immune-inflammation index.

Figure 4

Overall survival curves for patients by longitudinal changes in systemic inflammation. A-D: Patients were stratified into the low (preoperatively and post-chemotherapy low inflammatory state), normalized (preoperatively high but post-chemotherapy low inflammatory state), high (persistently high inflammatory state), and elevated (preoperatively low but post-chemotherapy high inflammatory state) groups. CAR: C-reactive protein/albumin ratio; NLR: Neutrophil-to-lymphocyte ratio; PLR: Platelet-to-lymphocyte ratio; SII: Systemic immune-inflammation index.