The USPSTF recommends against aspirin for prevention of colorectal cancer because it requires higher doses in order to accomplish this, but if aspirin is recommended for cardiovascular disease or stroke prevention, there would still be benefit obtained in the prevention of cancer, since according to the study by Bardia A et al, cancer incidence and cancer mortality was reduced even in patients that used aspirin infrequently compared to those that never used it (3).
Aspirin recommendations for diabetes patients from the American Heart Association (AHA) and the American Diabetes Association (ADA) (5):
Diabetes patients without history of vascular disease:
Diabetic patients without history of vascular disease but at increased risk of cardiovascular disease may benefit from the use of aspirin at a dose of 75–162 mg per day for primary prevention of cardiovascular disease. This would include men with diabetes over 50 and women with diabetes over 60 with additional risk factors of hyperlipidemia, family history of premature heart disease, high bp, smoking, and albuminuria only if there is no increased risk of bleeding or using other medications that can affect bleeding. Aspirin should not be used for diabetics without history of vascular disease in men under 50 years old or women under 60 years old and with a low risk of cardiovascular disease.