Table 1.
Demographic, clinical, and lifestyle characteristics of the breast (BC) and colorectal cancer (CRC) cases and controls in the WHI Bone Mineral Density subcohort 1.
| Characteristics | BC Cases (n = 577) |
CRC Cases (n = 181) |
Controls (n = 758) |
|---|---|---|---|
| Demographic factors | |||
| Age (yrs) | 62; [56, 68] | 64; [58, 69] | 63; [57, 68] |
| Body Mass Index (kg/m)2 | 27.73; [24.45, 32.45] * | 28.05; [24.9, 31.98] * | 27.16; [24.19, 31.18] |
| Waist circumference (cm) | 86; [77, 96] * | 87; [78, 99] * | 84; [76, 93] * |
| Self-reported race or ethnicity | |||
| Alaska Native or American Indian | <10 * | <10 * | <10 * |
| Asian or Pacific Islander | <10 * | <10 * | <10 * |
| Hispanic or Latina | 25 (4%) | 10 (6%) | 35 (5%) |
| Non-Hispanic Black or African American | 67 (12%) | 26 (14%) | 93 (12%) |
| White | 477 (83) | 139 (77%) | 616 (81) |
| Unknown | <10 | <10 | <10 |
| Education | |||
| Less than high school | 37 (6%) | 15 (8%) | 41 (5%) |
| High school or GED | 120 (21%) | 43 (24%) | 166 (22%) |
| School after high school | 209 (36%) | 74 (41%) | 284 (38%) |
| College degree or higher | 207 (36%) | 48 (27%) | 267 (35%) |
| Unknown | <10 | <10 | 0 |
| Income | |||
| <$20,000 | 104 (18%) | 56 (31%) | 165 (22%) |
| $20,000–$35,000 | 171 (30%) | 47 (26%) | 232 (31%) |
| $35,000–$50,000 | 100 (17%) | 37 (20%) | 132 (17%) |
| $50,000–$75,000 | 85 (15%) | 21 (12%) | 134 (18%) |
| >$75,000 | 81 (14%) | 13 (7%) | 95 (13%) |
| Unknown | 36 (6%) | <10 | 0 |
| Lifestyle factors | |||
| Alcohol intake (svgs/wk) | 0.42; [0, 1.81] * | 0.21; [0, 2.73] * | 0.21; [0, 1.37] |
| Total calcium (mg/d) | 1024.1; [647.5, 1557.2] * | 1029.3; [711.8, 1532.0] * | 973.8; [649.7, 1530.9] * |
| Total folate (mcg/d) | 635.47; [420.94, 881.23] * | 619.21; [448.25, 861.41] * | 593.64; [419.06, 838.82] * |
| Red or processed meat (svgs/d) | 1.87; [1.04, 2.95] * | 1.85; [1.1, 3.31] * | 1.83; [1.07, 3] * |
| Energy expenditure (MET-hours/wk) | 7.08; [1.5, 16.75] * | 7.25; [1.38, 16.42] * | 7; [1.5, 15.5] * |
| History of smoking (current yes/no) | 45 (7.84%) * | 16 (8.94%)* | 47 (6.2%) |
| Any supplement use | 257 (44.54%) * | 71 (39.23%) | 328 (43.27%) |
| Uses anti-diabetes medication | 24 (4.16%) | 16 (8.84%) | 35 (4.62%) |
| Uses anti-hypertensive medication | 185 (32.06%) | 68 (37.57%) | 231 (30.47%) |
| Uses anti-lipid medication | 42 (7.28%) | 16 (8.84%) | 50 (6.6%) |
| Uses NSAIDs | 196 (33.97%) | 58 (32.04%) | 262 (34.56%) |
| Clinical risk factors | |||
| Gail 5-year risk score | 1.9; [1.16, 2.22] | 1.7; [1.1, 1.92] | 1.68; [1.15, 1.95] |
| Family history of cancer | |||
| Yes | 80 (14%) | 30 (17%) | 124 (16%) |
| No | 453 (79%) | 139 (77%) | 617 (8%) |
| Unknown | 44 (8%) | 12 (7%) | 17 (2%) |
| Personal history of cancer | |||
| Yes | 27 (5%) | 13 (7%) | 39 (5.2%) |
| No | 547 (95%) | 168 (93%) | 719 (95%) |
| Unknown | <10 | 0 | 0 |
| History of colonoscopy | |||
| Yes | 253 (44%) | 71 (39%) | 355 (47%) |
| No | 249 (43%) | 90 (50%) | 401 (53%) |
| Unknown | 75 (13%) | 20 (11%) | <10 |
| History of colon polyp removal | |||
| Yes | 39 (7%) | 11 (6%) | 73 (10%) |
| No | 454 (79%) | 145 (80%) | 677 (89%) |
| Unknown | 84 (15%) | 25 (14%) | <10 |
| History of treated diabetes | |||
| Yes | 27 (5%) | 19 (11%) | 40 (5%) |
| No | 549 (95%) | 162 (90%) | 717 (95%) |
| Unknown | <10 | 0 | <10 |
| History of treated hypertension | |||
| Yes | 144 (25%) | 55 (30%) | 186 (25%) |
| No | 356 (62%) | 104 (57%) | 568 (75%) |
| Unknown | 77 (13%) | 22 (12%) | <10 |
| Had at least one term pregnancy | 510 (88%) | 158 (87%) | 676 (89%) |
| Post-menopausal hormone therapy use | |||
| Never | 286 (50%) | 97 (54%) | 331 (44%) |
| Past | 75 (13%) | 30 (17%) | 125 (16%) |
| Current estrogen alone | 117 (20%) | 36 (20%) | 189 (25%) |
| Current estrogen and progestin | 98 (17%) | 18 (10%) | 113 (15%) |
| Study variables | |||
| WHI enrollment date | |||
| Baseline | 108 (19%) | 44 (24%) | 152 (20%) |
| Year 1 | 220 (38%) | 65 (36%) | 285 (38%) |
| Year 3 | 243 (42%) | 68 (38%) | 311 (41%) |
| Year 6 | <10 | <10 | <10 |
| Year 9 | 0 | <10 | <10 |
| Calcium / Vitamin D (CaD) trial arm | |||
| Not randomized to CaD | 462 (80%) | 147 (81%) | 560 (74%) |
| Control arm | 54 (9%) | 19 (11%) | 104 (14%) |
| Intervention arm | 61 (11%) | 15 (8%) | 94 (12%) |
| Dietary Modification (DM) trial arm | |||
| Not randomized to DM | 384 (67%) | 122 (67%) | 488 (64%) |
| Control arm | 118 (20%) | 27 (15%) | 163 (22%) |
| Intervention arm | 75 (13%) | 32 (18%) | 107 (14%) |
| Hormone therapy (HT) trial arm | |||
| Not randomized to HT | 495 (86%) | 144 (80%) | 641 (85%) |
| Estrogen-only control arm | 19 (3%) | 13 (7%) | 27 (4%) |
| Estrogen-only intervention arm | 15 (3%) | 11 (6%) | 34 (4%) |
| Estrogen and progestin control arm | 16 (3%) | <10 | 30 (4%) |
| Estrogen and progestin intervention arm | 32 (6%) | <10 | 26 (3%) |
1 For continuous variables, the summaries displayed are: median; inter-quartile range. For binary and categorical variables, the summaries displayed are: count (proportion). * Denotes variables with a nonzero proportion of missing data. Overall, the proportion of missing data ranged from 0% to 11%, with most variables having less than 3% missing data. MET: metabolic equivalent hours per week of recreational physical activity; NSAIDs: non-steroidal anti-inflammatory drugs.