Oxidative Stress as a Biomarker for Predicting the Prognosis of Patients with Colorectal Cancer.

ABSTRACT

INTRODUCTION: Excess oxidative stress is generated by inflammation and cancer, and it is involved in the development and metastasis of colorectal cancer. However, there are few reports on the relationship between blood oxidative stress and prognosis. This study examined the usefulness of derivatives of reactive oxygen metabolites (d-ROMs), a measure of oxidative stress, and the neutrophil-to-lymphocyte ratio (NLR), an inflammatory marker, as prognostic markers in colorectal cancer. METHODS: The study enrolled 163 patients who underwent colorectal cancer resection at our institution between 2013 and 2018. Blood samples were taken preoperatively to measure d-ROMs and NLR. Spearman's correlation analysis was used to examine the relationships between d-ROMs and NLR, and Cox regression analysis was performed to identify factors associated with d-ROMs and NLR. The Kaplan-Meier method was used to calculate disease-specific survival (DSS). RESULTS: There was no correlation between d-ROMs and NLR. Tumor size was significantly associated with d-ROMs and NLR. DSS was significantly worse among patients with high d-ROMs or high NLR, although patients with high d-ROMs and high NLR had the worst DSS. In the multivariate analysis, distant metastasis and the high d-ROM/NLR combination were significant factors associated with DSS (p < 0.001, hazard ratio [HR] = 22.880 and p = 0.049, HR = 2.391, respectively). CONCLUSION: Preoperative d-ROMs and NLR reflect the tumor size among patients with colorectal cancer. The combination of d-ROMs and NLR may effectively predict prognosis in patients with colorectal cancer.