Longitudinal cohort study of long-term use of low-dose aspirin for cancer prevention in Hong Kong

A longitudinal cohort study in Hong Kong evaluated long-term use of low-dose aspirin for prevention of cancer. The population-based study included all aspirin users in Hong Kong between 2000 and 2019 (n=538,147). These users (90% using 80 mg per day) were age and sex matched in a 1:2 ratio with non-users (n=968,378). During 9,543,399 person-years of follow-up, long-term use of aspirin was associated with a reduced risk of cancer (sHR 0.92; 95% CI 0.91-0.94) and a reduced risk of cancer mortality (0,80; 0.70-0.82). Use of aspirin for longer than 10 years was associated with reduced risk of lung cancer (sHR 0.56; 95% CI 0,51-0.60), breast cancer (0.34;0.29-0.38), and colorectal cancer (0.37; 0.33-0.40) but not of bladder cancer and leukemia. The authors conclude that use of low-dose aspirin was associated with lower risk of cancer, with even stronger association for use longer than 10 years (graphical abstract).