Self-reported baseline and clinical characteristics of study subjects, the PLCO Cancer Screening Trial, 1993–2001
| Cases (N = 370) | Controls (N = 493) | ||
|---|---|---|---|
| n (%) or mean (SD) | n (%) or mean (SD) | P | |
| Age group, y | |||
| ≤59 | 83 (22.4) | 98 (19.9) | 0.78 |
| 60–64 | 127 (34.3) | 170 (34.5) | |
| 65–69 | 93 (25.1) | 126 (25.6) | |
| 70–74 | 67 (18.1) | 99 (20.1) | |
| Male | 196 (53.0) | 290 (58.8) | 0.09 |
| White | 327 (88.4) | 432 (87.6) | 0.74 |
| College graduated or higher | 113 (30.6) | 188 (38.4) | 0.02 |
| First-degree family history of colorectal cancer | 50 (13.5) | 59 (12.0) | 0.50 |
| Current cigarette smoker | 41 (11.1) | 52 (10.6) | 0.86 |
| Former cigarette smoker | 162 (43.8) | 225 (45.6) | |
| Regular aspirin or ibuprofen use (≥4/mo) | 218 (58.9) | 304 (61.7) | 0.41 |
| Current hormone use among females | 88 (44.0) | 112 (50.9) | 0.21 |
| Former hormone use among females | 33 (16.5) | 39 (17.7) | |
| Body mass index, kg/m2 | 27.5 (4.6) | 27.5 (5.0) | 0.87 |
| Alcohol, g/d | 13.8 (29.4) | 11.5 (20.4) | 0.23 |
| Natural food folate, μg/d | 302.0 (121.2) | 314.5 (125.8) | 0.17 |
| Fortified food folate, μg/d | 163.7 (91.8) | 181.9 (122.3) | 0.02 |
| Total folate equivalents (food and supplements), μg/d | 1,056.8 (722.8) | 1,088.8 (727.8) | 0.54 |
| Vitamin B6 (food and supplements), mg/d | 2.37 (0.9) | 2.47 (1.1) | 0.16 |
| Vitamin B12 (food and supplements), mg/d | 5.7 (3.0) | 5.9 (3.4) | 0.40 |
| Methionine (food), g/d | 1.7 (0.7) | 1.7 (0.7) | 0.46 |
| Distal carcinoma | 238 (51.5) | ||
| Stage I | 82 (16.1) | ||
| Stage II | 184 (39.8) | ||
| Stage III | 111 (24.0) | ||
| Stage IV | 93 (20.1) | ||