Background: The prognostic value and diagnostic accuracy of Interleukin-8 (IL-8) in colorectal cancer have been assessed with several studies, but the conclusions were inconclusive. Thus we performed a meta-analysis to evaluate the impact of IL-8 expression on colorectal cancer prognosis, clinicopathologic features and diagnostic accuracy.
Methods: Comprehensive search strategies were used to search relevant literature in the PubMed, EBSCO and the ISI Web of Science databases. The correlation between IL-8 expression and prognosis, clinicopathologic features and diagnostic accuracy was analyzed.
Results: A total of 18 articles met the inclusion criteria, including 1509 patients for clinicopathologic features or prognosis evaluation and 725 participants for diagnostic evaluation. The results suggested that overexpression of IL-8 was significantly associated with poor prognosis in colorectal cancer (HR = 1.54, 95%CI 1.03-2.32), especially in Union for International Cancer Control (UICC) stage IV patients (HR = 2.28, 95%CI 1.60-3.25). With further subgroup analysis, we found that high IL-8 level in serum was significantly correlated with poor prognosis (HR = 2.13, 95%CI 1.49-3.05). In addition, significant correlations were observed between high IL-8 expression and advanced stage (OR = 3.01, 95%CI 1.98-4.56), lymphatic metastasis (OR = 2.24, 95%CI 1.39-3.63), and liver metastasis (OR = 3.47, 95%CI 1.74-6.89). Moreover, IL-8 had high diagnostic accuracy, with pooled sensitivity 0.70(95%CI 0.66-0.74), specificity 0.91(95%CI 0.86-0.94), positive likelihood ratio (LR) 7.00(95%CI 2.48-19.73), negative LR 0.24(95%CI 0.09-0.64), diagnostic OR 24.00(95%CI 5.52-104.38).
Conclusions: This study showed that IL-8 could be a potential indicator for detecting colorectal cancer and predicting prognosis. In addition, high IL-8 level was significantly correlated with advanced stage, lymphatic metastasis, liver metastasis.