Table 1.
Characteristics of Randomized Participants Selected for Colon Tissue Metabolomics Study, by Aspirin Treatment Group (N=325)
| Placebo (N=100) | 81 mg Aspirin (N=114) | 325 mg Aspirin (N=111) | Pd | |
|---|---|---|---|---|
| Baseline Characteristics: | ||||
| Age at Enrollment, Mean ± SD | 57.8 ± 9.2 | 57.7 ± 8.1 | 58.7 ± 8.6 | 0.61 |
| Female, N (%) | 37 (37%) | 37 (33%) | 37 (33%) | 0.76 |
| Race/ethnicity, N (%) | 0.49e | |||
| White, Non-Hispanic | 86 (86%) | 97 (85%) | 100 (90%) | |
| Black, Non-Hispanic | 4 (4.0%) | 5 (4.4%) | 1 (0.9%) | |
| Hispanic | 6 (6.0%) | 7 (6.1%) | 3 (2.7%) | |
| Other | 4 (4.0%) | 5 (4.4%) | 7 (6.3%) | |
| Body-Mass Index, kg/m2, mean ± SD | 27.2 ± 4.6 | 27.3 ± 4.1 | 27.9 ± 4.8 | 0.53 |
| Current Smoker, N (%) | 13 (13%) | 11 (9.7%) | 14 (13%) | 0.69 |
| Alcohol Use, N (%) | 62 (66%) | 71 (65%) | 72 (67%) | 0.95 |
| Family History of Colorectal Cancer, N (%) | 33 (42%) | 35 (39%) | 37 (45%) | 0.71 |
| Study and Follow-up Characteristics: | ||||
| Allocated to Folate Treatment, N (%) | 48 (48%) | 63 (55%) | 60 (54%) | 0.53 |
| Study Follow-Up Time, Mean ± SDa | 32.7 ± 2.6 | 32.6 ± 2.3 | 32.7 ± 2.3 | 0.95 |
| ≥1 Adenoma at Year 3 Colonoscopy | 33 (33%) | 39 (34%) | 47 (42%) | 0.30 |
| ≥1 Advanced Adenoma at Year 3 Colonoscopyb | 6 (6.0%) | 8 (7.0%) | 13 (11.7%) | 0.27 |
| High-risk Findings at Year 3 Colonoscopyc | 9 (9.0%) | 11 (9.7%) | 16 (14.4%) | 0.38 |
| Paired Baseline and Year 3 Plasma Samples Analyzed for Aspirin Metabolites, N (%) | 90 (90%) | 105 (92%) | 98 (88%) | 0.63 |
Note: N’s for missing data for alcohol use: 6 placebo, 4 aspirin (81 mg), 3 aspirin (325 mg); for family history of colorectal cancer: 21 placebo, 24 aspirin (81 mg), 29 aspirin (325 mg).
Time in months from enrollment to year 3 end of treatment colonoscopy.
Advanced adenomas are those with cancer, high-grade dysplasia, >25% villous component, or diameter ≥1 cm.
High-risk refers to ≥1 advanced adenomas or ≥3 adenomas of any type.
P-values for comparisons among the three treatment groups: Pearson chi-square tests for categorical variables and analysis of variance likelihood ratio chi-square tests for continuous variables.
P-value using Fisher’s exact test.