Stage-dependent alterations of the serum cytokine pattern in colorectal carcinoma

BACKGROUND: Inflammation contributes to the pathogenesis of colorectal cancer (CRC), and cytokine levels are altered during colorectal carcinogenesis. METHODS: The serum levels of 13 cytokines and their relation to clinical and pathological parameters, and systemic inflammatory response (mGPS, CRP and neutrophil–lymphocyte ratio), were analysed from a prospective series of 148 CRC patients and 86 healthy age- and sex-matched controls. RESULTS: CRC patients had higher serum platelet-derived growth factor, interleukin (IL)-6, IL-7, and IL-8 levels and lower monocyte chemotactic protein-1 (MCP-1) levels than the controls. A logistic regression model for discriminating the patients from the controls – including the five most predictive cytokines (high IL-8, high IL-6, low MCP-1, low IL-1ra, and low IP-10) – yielded an area under curve value of 0.890 in receiver operating characteristics analysis. Serum cytokines showed distinct correlation with other markers of systemic inflammatory response, and advanced CRCs were associated with higher levels of IL-8, IL-1ra, and IL-6. A metastasised disease was accompanied by an orientation towards Th2 cytokine milieu. CONCLUSION: CRC is associated with extensive alterations in serum cytokine environment, highlighting the importance of studying relative cytokine level alterations. Serum cytokine profile shows promise in separating CRC patients from healthy controls but its clinical value is yet to be confirmed.