Association between regular aspirin use and circulating markers of inflammation: A study within the prostate, lung, colorectal, and ovarian cancer screening trial

Background: Regular aspirin use may decrease cancer risk by reducing chronic inflammation. However, associations between aspirin use and circulating markers of inflammation have not been well studied. Methods: Serum levels of 78 inflammatory markers were measured in 1,819 55- to 74-year-old men and women in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. Data were combined from three completed case-control studies and reweighted to the PLCO screening arm. Self-reported aspirin and ibuprofen use (number of tablets taken per day/week/month) over the previous 12 months was collected at baseline. Associations between (i) nonregular (<4 tablets/month), (ii) low (1-4 tablets/week), (iii) moderate (1 tablet/day), or (iv) high (2+ tablets/day) regular aspirin or ibuprofen use and marker levels were assessed with weighted logistic regression. Results: Aspirin use was nominally associated with (P_trendacross categories ≤ 0.05) decreased levels of chemokine C-C motif ligand 15 [CCL15; OR, 0.5; 95% confidence intervals (CI), 0.3-0.8; moderate versus nonregular use]; soluble vascular endothelial growth factor receptor 2 (sVEGFR2; OR, 0.7; 95% CI, 0.4-1.0); soluble tumor necrosis factor receptor 1 (sTNFR1; OR, 0.6; 95% CI, 0.4-0.9) and increased levels of CCL13 (OR, 1.3; 95% CI, 0.8-2.1); CCL17 (OR, 1.1; 95% CI, 0.7-1.9) and interleukin 4 (IL4; OR, 1.6; 95% CI, 0.9-2.8). Trends were not statistically significant following correction for multiple comparisons. Likewise, no statistically significant associations were observed between ibuprofen use and marker levels. Conclusions: No significant associations were observed between regular aspirin use and the inflammatory markers assessed. Impact: Additional studies are needed to better understand the relationship between aspirin use, chronic inflammation, and cancer risk.