Low-dose aspirin use and risk of head and neck cancer-A Danish nationwide case-control study.

Results concerning a potential preventive effect of aspirin on head and neck cancer (HNC) are conflicting. We examined the association between low-dose aspirin use and HNC risk overall and by degree of human papillomavirus association in a nested case-control study using nationwide registries. Cases (n = 12 389) were all Danish residents diagnosed with primary HNC (2000-2015). Age- and sex-matched population controls (n = 185 835) were selected by risk-set-sampling. Using conditional logistic regression, we estimated multivariable-adjusted odds ratios and 95% confidence intervals for HNC associated with low-dose aspirin use (≥2 prescriptions). No association was observed between low-dose aspirin ever-use and overall HNC (odds ratio: 1.03, 95% confidence interval: 0.97-1.10). Estimates remained neutral according to patterns of use. Low-dose aspirin use appeared to slightly decrease HNC risk among the eldest (71-84 y), independently of human papillomavirus association, while slightly increase HNC risk among younger age groups (30-60, 61-70 y), driven by an increased risk of oral cancer. However, no consistent patterns in risk estimates were found according to duration and consistency of low-dose aspirin use in the age-stratified analyses.