Significance of Markers of Systemic Inflammation for Predicting Survival and Chemotherapeutic Outcomes and Monitoring Tumor Progression in Patients with Unresectable Metastatic Colorectal Cancer

Abstract Markers of systemic inflammation, such as the neutrophil to lymphocyte ratio (NLR), C-reactive protein (CRP) level and Glasgow prognostic score (GPS), have been reported to be useful prognostic indicators for various types of cancers. However, most of the existing reports investigated the preoperative status, and the significance of markers of systemic inflammation remains unclear in patients with unresectable metastatic colorectal cancer. The aim of the present retrospective study was to evaluate the significance of markers of systemic inflammation for predicting the prognosis and chemotherapeutic outcomes and monitoring the progression of the tumor in patients with unresectable metastatic colorectal cancer receiving palliative chemotherapy. A total of 110 patients with unresectable metastatic colorectal cancer who underwent palliative chemotherapy for metastatic tumors were enrolled in the study. We evaluated the relationships between the survival/chemotherapeutic response and pre-/post-treatment markers of systemic inflammation. The pre-treatment markers of systemic inflammation were measured within one week before the initiation of chemotherapy and the post-treatment markers of systemic inflammation were measured eight weeks after initiation of chemotherapy. The overall survival rates were significantly worse in the group with high pre-treatment NLR/CRP/GPS, and that with high post-treatment CRP/GPS; the progression-free survival rate was significantly worse in the high post-treatment CRP group. As for chemotherapeutic response, patients with a low post-treatment CRP level had a significantly higher disease control rate than those with a high post-treatment CRP level. Moreover, the patients with a high pre-treatment CRP level and normalization after treatment exhibited better overall and progression-free survival rates and had a significantly higher disease control rate than those with high pre- and post-treatment CRP levels. Pre-treatment markers of systemic inflammation are useful for predicting prognosis in patients with unresectable metastatic colorectal cancer who receive palliative chemotherapy. Moreover, the CRP level can be used as a marker for predicting chemotherapeutic outcome and monitoring the progression of the tumor.