Association between baseline C-reactive protein and the risk of lung cancer: a prospective population-based cohort study

Abstract C-reactive protein (CRP), a systemic marker of diagnosing chronic inflammation, has been associated with the incidence of multiple types of cancer. However, little is known about the impact of CRP on lung cancer incidence in Chinese population. A total of 97,950 participants without cancer at baseline (2006-2007) of the Kailuan Cohort Study were followed up. The concentration of plasma high-sensitivity CRP (hsCRP) was tested for all participants at baseline interview. Multivariable Cox proportional hazards regression models were used to assess the association between levels of hsCRP and incident lung cancer. During 8.7-year follow-up, 890 incident lung cancer cases occurred and were divided into three groups according to the level of hsCRP. The risk of incident lung cancer was significantly increased with elevated levels of hsCRP [hazard ratio (HR)Medium/Low=1.21, 95% confidence interval (CI)=1.03-1.42; HRHigh/Low=1.42, 95%CI=1.20-1.68; Ptrend<0.001], compared to the low group after adjusting confounders. Moreover, after stratifying by BMI, the significantly positive associations between the hsCRP level and the risk of lung cancer were found among those with BMI<24 (HRHigh/Low=1.51, 95%CI=1.18-1.94; Ptrend=0.001) and BMI=24-28 (HRHigh/Low=1.47, 95%CI=1.13-1.92; Ptrend=0.003), but not among those with BMI≥28 (HRHigh/Low=1.01, 95%CI=0.64-1.57; Ptrend=0.991). There was an antagonistic interaction between hsCRP levels and BMI that contributed to development of lung cancer (Pinteraction=0.049). In conclusion, these findings indicate a dose-dependent relationship between hsCRP and lung cancer risk among Chinese population, especially in non-obese participants, suggesting that CRP could serve as a potential biomarker for prediction of lung cancer risk and identification of high-risk population.