To the Editor Cao et al1 provided an emphasis regarding cancer prevention using aspirin in 2 large prospective cohort studies: the Nurses’ Health Study and Health Professionals Study. Overall cancer risk reduction was minimal, with a relative risk of 0.97 (95% CI, 0.94-0.99). The major benefit was for gastrointestinal cancers, mainly colorectal cancers. In 2016, colorectal cancer is estimated to make up 8% of all new cancer cases in United States.2 The US Preventive Services Task Force recommends low-dose aspirin therapy for primary prevention of colorectal cancer for patients from age 50 to 59 years if they have a life expectancy of at least 10 years and are willing to take it for at least 10 years.3 In their study, the effect of aspirin therapy was cumulative and needed at least 6 years to show benefit.
Samer Al Hadidi. Aspirin and Cancer Risk. JAMA Oncol. 2016;2(10):1371–1372. doi:10.1001/jamaoncol.2016.2332