Aspirin, cyclooxygenase inhibition and colorectal cancer

Table 4 Clinical effects of aspirin in incidence of sporadic colorectal adenomas (clinical trials)

Study	Patients	Treatment	RR (95%CI)
AFPPS trial	Patients with a recent history of histologically documented (removed) adenomas	ASA (81 or 325 mg/d) or folic acid (1 mg/d) or placebo for 2.7 years	Any adenoma 0.81 (0.69-0.96), ASA 81mg vs non ASA 0.96 (0.81-1.13), ASA 325 mg vs non ASA Advanced lesion 0.59 (0.38-0.92), ASA 81 mg vs non ASA 0.83 (0.55–1.23), ASA 325 mg vs non ASA
CAPS trial	Patients with a histologically documented colon or rectal cancer with a low risk of recurrent disease	ASA 325 mg/d or placebo for 2.6 years	0.65 (0.46-0.91)
APACC trial	Patients with a history of colorectal adenomas	ASA 160 or 300 mg/d or placebo for 1 and 4 years	0.73 (0.52-1.04) for both doses, after 1 year 0.96 (0.75-1.22), for both doses, after 4 years
ukCAP trial	Patients with an adenoma removed in the 6 mo before recruitment	ASA (300 mg/d) plus placebo or ASA plus folic acid (0.5 mg/d) or folic acid plus placebo or double placebo for about 2.6 years	Any adenoma 0.79 (0.63-0.99), ASA vs non ASA, Advanced adenoma 0.63 (0.43-0.91), ASA vs non ASA
J-CAPP trial	Patients with previous sporadic colorectal tumors	ASA 100 mg/d or placebo for 2 years	Ongoing

ASA: Aspirin.