Inflammatory biomarkers, aspirin, and risk of colorectal cancer: Findings from the physicians’ health study

Abstract

BackgroundChronic inflammation has been implicated in colorectal carcinogenesis. However, the associations between plasma inflammatory markers and risk of colorectal cancer have been inconsistent. MethodsIn a nested case-control study in the Physicians’ Health Study, we prospectively investigated the associations of plasma C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor receptor 2 (TNFR-2) with risk of colorectal cancer, and whether aspirin modified these associations among 268 colorectal cancer patients and 446 age- and smoking-matched controls. ResultsIn multivariate-adjusted models, plasma levels of CRP, IL-6 and TNFR-2 were not significantly associated with risk of colorectal cancer, although a positive trend was observed for TNFR-2 (RRhighestvs.lowestquartile=1.55; 95% CI=0.95-2.54; Ptrend=0.05). We observed a statistically significant association between elevated TNFR-2 levels and colorectal cancer risk in the placebo arm (RRhighestvs.lowesttertile=1.77; 95% CI=1.02-3.06; Ptrend=0.02), but not in the aspirin arm (Ptrend=0.72). However, the interaction between TNFR-2 and aspirin was not statistically significant (Pinteraction=0.34). ConclusionPlasma inflammatory markers were not significantly associated with colorectal cancer risk among men, though there was a statistically non-significant positive trend between TNFR-2 and colorectal cancer risk. More studies are required to understand the relationship between the role of TNFα pathway, aspirin, and colorectal cancer risk.