Table 2.
Effects of Aspirin on Adenoma Recurrence Compared With Placebo in the Four Published Randomized Controlled Trials.
| Study (references) | No. of patients | Daily dose of aspirin (mg) MDTM | Exposure (py) recurrence (R) with placebo | Patients with at least one adenoma | Patients with at least one advanced adenoma | Mean ± SD no. of adenomas/patient |
|---|---|---|---|---|---|---|
| APACC 1 y | 238 | 160/300 1 y |
Asp 38/126 (30%) vs Pla 46/112 (41%) RR 0.73 (0.52 to 1.04) P = .04 |
Asp 8/126 (6%) vs Pla 13/112 (12%) RR 0.55 (0.24-1.27) NS |
Asp 0.45 + 0.15 vs Pla 0.86 ± 0.3 P = .01 |
|
| APACC 4 y | 185 | 160/300 3.4 y |
629 py 207 py |
Asp 65/128(51%) vs Pla 61/115 (53%) RR 0.96 (0.75-1.22) NS |
Asp 18/128 (14%) vs Pla 18/115 (16%) RR 0.90 (0.50-1.64) NS |
Asp 1 ± 1.5 vs Pla 1.5 ± 2.4 P = .07 |
| UKcap30 | 954 | 300 2.6 y |
2218 py 452R |
Asp 99/434 (23%) vs Pla 121/419 (29%) RR 0.79 (0.63-0.99) P = .04 |
Asp 41/434 (9%) vs Pla 63/419 (15%) RR 0.63 (0.43-0.91) P = .013 |
Asp 0.3 ± 0.7 vs Pla 0.5 ± 0.9 P = .015 |
| CAPS28 | 635 | 325 2.6 y |
1344 py 181 R |
Asp 43/259 (17%) vs Pla 70/258 (27%) RR 0.65 (0.46-0.91) P = .004 |
NS | Asp 0.3 ± 0.9vs Pla 0.5 ± 1 P = .003 |
| AFPPS29 | 1121 | 81/325 2.7 y |
2927 py 461 R |
140/366 (38%) (38%) Asp 81 mg vs 160/355 (45%) Asp 325 mg vs 171/363 (47%) Pla RR Asp 81 mg:0.81 (0.69-0.96 P = .04 RR Asp 325 mg:0.96 (0.81-1.13) |
28/366 (8%) Asp 81 mg vs 38/355 (13%) Pla RR Asp 81 mg:0.59 (0.38-0.92) P < .05 |
Not done |
Note. Asp = Aspirin; MDTM = mean duration of trial medication; py, patient years; APACC = Association Prevention of Colorectal Cancer and Aspirin; Pla = placebo; RR = relative risk; AFPPS = Aspirin/Folate Polyp Prevention Study.24