Association between aspirin use and lung cancer incidence depends on high-frequency use, bodyweight, and age in U.S. adults

Background Chemoprevention of cancer with aspirin is controversial as a primary prevention strategy. We sought to investigate the association between aspirin frequency and risk of lung cancer in The Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. Methods Using data from 101,722 participants in PLCO, we used a Cox regression model coupling with propensity score to detect the association between aspirin frequency and lung cancer risk. Results High-frequency aspirin use significantly increased risk of lung cancer by 28% compared to no use (HR =1.28; 95% CI, 1.14-1.45; P=3.37×10-5), especially for current smoker (HR =1.30; 95% CI, 1.07-1.57; P=6.82×10-3). However, the increased lung cancer risk due to high-frequency aspirin use significantly decreased with increasing bodyweight (HRinteraction =0.96; 95% CI, 0.94-0.99; P=1.26×10-2). Further, for participants with bodyweight <80 kg, high-frequency aspirin use showed an elevated risk at <76 years of age (HRage<76 =1.47; 95% CI, 1.25-1.73; P=3.81×10-6). Our study used propensity score under various confounding and stratification analyses by cardio-cerebrovascular status, which all presented similar evidences. Conclusions High-frequency aspirin use is associated with the increased risk of lung cancer. Current smoker or people with age <76 years and bodyweight <80 kg should be more cautious to high-frequency aspirin use for lung cancer chemoprevention. This study provides a new insight for lung cancer chemoprevention.