Results
D uring follow-up through June 2003, 10 9 31 men and 7196 women were diagnosed with cancer.
Longterm ( ≥ 5 years) daily use of adult-strength aspirin, compared with no use, was associated with lower overall cancer incidence in men (multivariable-adjusted RR = 0.84, 95% confidence interval [CI] = 0.76 to 0.93) and non–statistically significantly lower overall cancer incidence in women (multivariable-adjusted RR = 0.86, 95% CI = 0.73 to 1.03).
Overall cancer incidence per 100 0 00 person-years (standardized to the age distributions of men and women in the study) with long-term daily aspirin use and no aspirin use was 1858 and 2163, respectively, among men and 1083 and 1169, respectively, among women.
Long-term daily aspirin use was associated with lower incidence of colorectal cancer (RR = 0.68, 95% CI = 0.52 to 0.90 among men and women combined) and prostate cancer (RR = 0.81, 95% CI = 0.70 to 0.94) and a non–statistically significant lower risk of female breast cancer (RR = 0.83, 95% CI = 0.63 to 1.10).