Serum C-reactive protein correlates with survival in colorectal cancer patients but is not an independent prognostic indicator

Abstract

Background C-reactive protein (CRP) is an acute-phase protein synthesized in liver and up-regulated by pro-inflammatory cytokines, such as interleukin-6 (IL-6), interleukin-8 (IL-8) and tumour necrosis factor (TNF). Elevated CRP has been reported to be associated with reduced crude survival rates in patients with colorectal cancer. Objective To investigate the prognostic significance of preoperative serum CRP in relation to the disease-specific survival rate and expression of different cytokines. Methods One hundred and seventy-two consecutive patients with colorectal cancer, whose primary lesions were resected, were selected from April 1995 to December 1999. Preoperative serum CRP levels were measured, and the relationship between the elevation of CRP and clinicopathological factors was investigated. Prognostic significance was analysed by univariate and multivariate tests. Results One-third of patients had increased CRP levels, and this was associated with larger tumour size, lymph node or liver metastasis, and advanced Dukes’ stage. Higher CRP levels were also related to the elevation of IL-6 and IL-8. The most important prognostic factor predicting survival was Dukes’ stage (P< 0.001). Multivariate analysis indicated that CRP level is not an independent factor predicting survival. Conclusions A preoperative elevation of serum CRP does not have the independent prognostic significance reported by earlier studies. Whether the elevated CRP can predict the development of cachexia or whether this association characterizes a pattern in tumour behaviour remains to be determined.