Derived neutrophil to lymphocyte ratio as a prognostic factor in patients with advanced colorectal cancer according to RAS and BRAF status

The phase III Continuous or Intermittent (COIN) trial failed to show a benefit in overall survival (OS) of cetuximab in combination with chemotherapy for patients with metastatic colorectal cancer. High derived neutrophil to lymphocyte ratio (dNLR) has been shown to be prognostic in patients with metastatic colorectal cancer. The aim of this analysis is to evaluate dNLR as a predictive biomarker of the survival according to RAS and BRAF mutations status within the COIN trial. A post-hoc exploratory analysis of the COIN trial arms A and B was carried out. All patients with available white blood cell and neutrophil data were analysed. The dNLR was calculated using a formula that has previously shown predictive power in cancer patients: dNLR=ANC/(WBC−ANC). A high dNLR was defined as a value of 2.2 or more. dNLR was correlated with clinical outcomes using Kaplan–Meier and Cox regression analysis. A total of 1603 patients were assigned to the oxaliplatin-based chemotherapy (arm A, N=815) or oxaliplatin-based chemotherapy plus cetuximab (arm B, N=815) arms. There was a strong association between dNLR level and overall survival (OS) using Kaplan–Meier analysis. In all mutation groups, dNLR less than 2.2 was associated with better OS compared to dNLR of 2.2 or more. The median OS in patients with wild-type disease (dNLR