Summary of cited randomized clinical trials
| Study . | Trial . | Study period . | Population . | Intervention . | Follow-up time, y . | Efficacy . |
|---|---|---|---|---|---|---|
| Baron et al29 | The Aspirin/Folate Polyp Prevention Study | 1994 to 1998 | N = 1121; previous sporadic colorectal adenomas; mean age, 57 y | Factorial design: 325 mg of aspirin daily vs 81 mg of aspirin daily vs placebo, ± folic acid | Colonoscopy at ∼3 y | Any recurrent adenoma: 45.1% vs 38.3% vs 47.1% (global P = .04); HR, 0.96 (95% CI, 0.81-1.13; P = .06) for 325 mg; HR, 0.81 (95% CI, 0.69-0.96) for 81 mg. Advanced lesions: 10.7% vs 7.7% vs 12.9%; RR, 0.83 (95% CI, 0.55-1.23) for 325 mg; RR, 0.59 (95% CI, 0.38-0.92) for 81 mg. |
| Logan et al30 | The United Kingdom Colorectal Adenoma Prevention (ukCAP) | 1997 to 2005 | N = 945; previous sporadic colorectal adenomas; mean age, 57.8 y | Factorial design: 300 mg of aspirin daily vs placebo, ± folic acid | Colonoscopy at ∼3 y | Any recurrent adenoma: 22.8% vs 28.9%; RR, 0.79 (95% CI, 0.63-0.99). Absolute risk reduction, 6.1%. Advanced adenoma: 9.4% vs 15.0%; RR, 0.63 (95% CI, 0.43-0.91). |
| Cook et al31 | Women’s Health Study (WHS) | 1992 to 2004 | N = 39 876; healthy women age ≥45 y, 33 682 of whom continued observational follow-up; mean age at trial entry, 54.6 y | 100 mg of aspirin daily vs placebo | Median 10 y of active intervention; median extended follow-up, 17.5 y | Cancer incidence: 12.6% vs 12.8%; HR, 0.97 (95% CI, 0.92-1.03; P = .31). CRC: 1.0% vs 1.2%; HR, 0.80 (95% CI, 0.67-0.97; P = .021). Absolute risk reduction, 0.2%. |
| ASCEND Study Collaborative Group32 | A Study of Cardiovascular Events in Diabetes (ASCEND) | 2005 to 2011 | N = 15 480; age ≥40 y; T2DM and no CVD; mean age, 63 y | 100 mg of aspirin daily vs placebo | Mean, 7.4 y | Cancer mortality: 4.0% vs 4.1%; HR, 0.98 (95% CI, 0.84-1.15). Absolute risk reduction, 0.1%. Cancer incidence: 11.6% vs 11.5%; HR, 1.01 (95% CI, 0.92-1.11). Absolute risk increase, 0.1%. |
| Gaziano et al33 | ARRIVE | 2007 to 2016 | N = 12 546; average cardiovascular risk men (age ≥55 y) and women (age ≥50 y); mean age, 63.9 y | 100 mg of aspirin daily vs placebo | Median, 5 y | Cancer incidence: 4.02% vs 3.76%; HR, 1.07 (95% CI, 0.89-1.27; P = .475). Absolute risk increase, 0.26%. |
| McNeil et al34 | ASPREE | 2010 to 2014 | N = 19 114; age ≥70 y or US minorities age ≥65 y; without CVD, dementia, or disability; median age, 74 y; 9% of total cohort was from minority groups | 100 mg of aspirin daily vs placebo | Median, 4.7 y | Cancer mortality: 3.1% vs 2.3%; HR, 1.31 (95% CI, 1.10-1.56; P = .002). Absolute risk increase, 0.73%. |
| Study . | Trial . | Study period . | Population . | Intervention . | Follow-up time, y . | Efficacy . |
|---|---|---|---|---|---|---|
| Baron et al29 | The Aspirin/Folate Polyp Prevention Study | 1994 to 1998 | N = 1121; previous sporadic colorectal adenomas; mean age, 57 y | Factorial design: 325 mg of aspirin daily vs 81 mg of aspirin daily vs placebo, ± folic acid | Colonoscopy at ∼3 y | Any recurrent adenoma: 45.1% vs 38.3% vs 47.1% (global P = .04); HR, 0.96 (95% CI, 0.81-1.13; P = .06) for 325 mg; HR, 0.81 (95% CI, 0.69-0.96) for 81 mg. Advanced lesions: 10.7% vs 7.7% vs 12.9%; RR, 0.83 (95% CI, 0.55-1.23) for 325 mg; RR, 0.59 (95% CI, 0.38-0.92) for 81 mg. |
| Logan et al30 | The United Kingdom Colorectal Adenoma Prevention (ukCAP) | 1997 to 2005 | N = 945; previous sporadic colorectal adenomas; mean age, 57.8 y | Factorial design: 300 mg of aspirin daily vs placebo, ± folic acid | Colonoscopy at ∼3 y | Any recurrent adenoma: 22.8% vs 28.9%; RR, 0.79 (95% CI, 0.63-0.99). Absolute risk reduction, 6.1%. Advanced adenoma: 9.4% vs 15.0%; RR, 0.63 (95% CI, 0.43-0.91). |
| Cook et al31 | Women’s Health Study (WHS) | 1992 to 2004 | N = 39 876; healthy women age ≥45 y, 33 682 of whom continued observational follow-up; mean age at trial entry, 54.6 y | 100 mg of aspirin daily vs placebo | Median 10 y of active intervention; median extended follow-up, 17.5 y | Cancer incidence: 12.6% vs 12.8%; HR, 0.97 (95% CI, 0.92-1.03; P = .31). CRC: 1.0% vs 1.2%; HR, 0.80 (95% CI, 0.67-0.97; P = .021). Absolute risk reduction, 0.2%. |
| ASCEND Study Collaborative Group32 | A Study of Cardiovascular Events in Diabetes (ASCEND) | 2005 to 2011 | N = 15 480; age ≥40 y; T2DM and no CVD; mean age, 63 y | 100 mg of aspirin daily vs placebo | Mean, 7.4 y | Cancer mortality: 4.0% vs 4.1%; HR, 0.98 (95% CI, 0.84-1.15). Absolute risk reduction, 0.1%. Cancer incidence: 11.6% vs 11.5%; HR, 1.01 (95% CI, 0.92-1.11). Absolute risk increase, 0.1%. |
| Gaziano et al33 | ARRIVE | 2007 to 2016 | N = 12 546; average cardiovascular risk men (age ≥55 y) and women (age ≥50 y); mean age, 63.9 y | 100 mg of aspirin daily vs placebo | Median, 5 y | Cancer incidence: 4.02% vs 3.76%; HR, 1.07 (95% CI, 0.89-1.27; P = .475). Absolute risk increase, 0.26%. |
| McNeil et al34 | ASPREE | 2010 to 2014 | N = 19 114; age ≥70 y or US minorities age ≥65 y; without CVD, dementia, or disability; median age, 74 y; 9% of total cohort was from minority groups | 100 mg of aspirin daily vs placebo | Median, 4.7 y | Cancer mortality: 3.1% vs 2.3%; HR, 1.31 (95% CI, 1.10-1.56; P = .002). Absolute risk increase, 0.73%. |
CI, confidence interval; CRC, colorectal cancer; CVD, cardiovascular disease; HR, hazard ratio; RR, relative risk; T2DM, type 2 diabetes mellitus.