Long-term effect of aspirin on colorectal cancer incidence and mortality: 20-year follow-up of five randomised trials
Background High-dose aspirin (>= 500 mg daily) reduces long-term incidence of colorectal cancer, but adverse effects might limit its potential for long-term prevention. The long-term effectiveness of lower doses (75-300 mg daily) is unknown. We assessed the effects of aspirin on incidence and mortality due to colorectal cancer in relation to dose, duration of treatment, and site of tumour. Methods
