Plasma C-reactive protein and risk of cancer: a prospective study from Greece.

BACKGROUND Inflammation is an important component of carcinogenesis but little research has been conducted on whether inflammation markers can be predictive of cancer risk in humans. METHODS We analyzed C-reactive protein (CRP), a marker of inflammation, in plasma samples of 496 cases of cancer and 996 controls selected among participants in a prospective study from Greece. RESULTS Plasma CRP level was higher in cancer cases than controls (odds ratio for increase in CRP level of 3.2 mg/L, 1.20; 95% confidence interval, 1.10-1.32): The corresponding odds ratio after exclusion of the first year of follow-up and of individuals with CRP level above 20 mg/L was 1.32 (95% confidence interval, 1.15-1.52). Although based on small number of cases, the association between elevated plasma CRP level and risk was stronger for cancers of the liver, lung, skin, kidney, and bladder, as well as for lymphoma and leukemia than for other neoplasms. CONCLUSIONS Our results confirm the important role of inflammation in human cancer and suggest that plasma CRP level is a potential marker of increased cancer risk.