Postoperative C-reactive protein/albumin ratio is a biomarker of risk of recurrence and need for adjuvant chemotherapy for stage III colorectal cancer

Background Adjuvant chemotherapy is generally recommended for patients with stage III colorectal cancer. Even with adjuvant chemotherapy, 20–30% of such patients develop recurrences; the risk factors for recurrence are currently unclear. The preoperative systemic inflammation index has been linked to poor prognoses in patients with colorectal cancer; however, the relationship between postoperative systemic inflammation index and recurrence is unclear. We aimed to evaluate the association between preoperative and postoperative systemic inflammation indexes and recurrence in patients with stage III colorectal cancer. Methods The following laboratory data of 133 patients with stage III colorectal cancer were analyzed: preoperative and postoperative C-reactive protein/albumin ratios (CAR); neutrophil to lymphocyte ratios (NLR); and platelet to lymphocyte ratios (PLR) and their relationships with recurrence analyzed. Results The optimal cutoff values for systemic inflammation indexes were determined by examining receiver operating characteristic curves. Multivariate analyses indicated that N-stage, postoperative complications, preoperative NLR, and postoperative CAR were independent predictors of recurrence-free survival (RFS). Postoperative CAR was also an independent predictor of overall survival (OS). Patients with postoperative CAR ≥ 0.035 who did not receive adjuvant chemotherapy had shorter RFS and OS than those who did. There were no significant differences in RFS and OS between patients with postoperative CAR < 0.035 who did and did not receive adjuvant chemotherapy. Conclusions Postoperative CAR is strongly associated with poor prognosis in patients with stage III colorectal cancer and is a useful biomarker for determining whether adjuvant chemotherapy should be administered.