Preoperative C-reactive Protein as a Prognostic Factor in Stage IV Colorectal Cancer

Abstract Background: A prognosis for stage IV colorectal cancer is generally poor. As a result, the development of an appropriate treatment strategy for each individual with this disease within a limited time frame is important. In various malignancies, preoperative high C-reactive protein (CRP) levels may be a possible poor prognostic factor. However, few studies have been made of CRP in stage IV cases of colorectal cancer so it is unclear whether CRP is a useful prognostic marker for this disease. Thus, the purpose of this study was to clarify the relationship between the preoperative CRP level and the prognosis of stage IV colorectal cancer.Patients and methods: Between April 2007 and December 2015, 384 patients with stage IV colorectal cancer who underwent primary resection were included. Patients were divided into high (HCG) and low (LCG) CRP groups based on a preoperative CRP cut-off value of ³1.0 mg/dL. Postoperative short- and long-term results were examined retrospectively.Results: Preoperative carcinoembryonic antigen (CEA) levels were higher in HCG; the number of R0 surgical resections of distant metastases was smaller. The 5-year survival rate was 24.6% for HCG and 36.7% for LCG, indicating the survival rate for HCG was lower. A multivariate analysis of factors affecting survival rates identified CRP >1.0, histopathological type, positive venous infiltration, and R0 inoperability as risk factors. The rate of R0 resection was higher in LCG. Concerning R0 resection patients, differences between HCG and LCG with regard to background factors, including preoperative CEA levels, were not found. In terms of long-term survival, a significant difference in overall survival between the two groups was not observed. The study was limited to patients who were unable to undergo R0 surgery. Preoperative CEA levels were higher in HCG while the postoperative chemotherapy induction rate was lower. HCG also showed a significantly lower survival rate than LCG. Multivariate analysis showed that CRP levels above 1.0 mg/dL, poorly differentiated histopathology, and the absence of chemotherapy were risk factors affecting overall survival.Conclusion: These results suggest that the preoperative CRP level may be a useful biomarker for the prognosis of incurable stage IV colorectal cancer.