Table 1.
Characteristics of cases and controls within a nested case-control cohort of the WHEL Study
| Cases (n = 153) | Controls (n = 153) | P | |
|---|---|---|---|
| Chemotherapy during initial treatment (%) | 76.5 | 75.8 | 0.86 |
| Tumor estrogen receptor status (%) | |||
| Estrogen receptor positive | 77.1 | 78.4 | 0.79 |
| Estrogen receptor negative | 21.6 | 20.3 | |
| Tamoxifen use at baseline (%) | 68.0 | 73.2 | 0.32 |
| Age, y | 55 (8) | 55 (7) | 0.56 |
| Ethnicity (%) | |||
| White non-Hispanic | 83.7 | 88.9 | 0.14 |
| Hispanic | 7.8 | 3.9 | |
| Other | 8.5 | 7.2 | |
| Body mass index, kg/m2 | 27.9 (5.7) | 27.8 (5.7) | 0.83 |
| Physical activity METs, min/wk | 703 (768) | 742 (791) | 0.67 |
| Waist/hip circumference ratio | 0.81 (0.07) | 0.81 (0.09) | 0.57 |
| Prior menopausal hormone therapy (%) | 54.9 | 54.3 | 0.90 |
| Hot flashes at baseline (%) | 67.3 | 68.6 | 0.89 |
| History of bilateral oophorectomy (%) | 13.1 | 15.7 | 0.54 |
| Baseline dietary fiber intake, g/d | 20.2 (7.0) | 21.4 (8.1) | 0.14 |
| Time from diagnosis to randomization, mo | 23.1 (12.0) | 24.6 (11.3) | 0.08 |
| Tumor stage (%)* | |||
| I | 17.7 | 17.7 | 1.00 |
| IIA | 32.7 | 32.7 | |
| IIB | 15.7 | 15.7 | |
| IIIA | 21.6 | 21.6 | |
| IIIC | 12.4 | 12.4 | |
| Tumor grade (%) | |||
| I | 8.5 | 14.4 | 0.13 |
| II | 43.8 | 38.6 | |
| III | 38.6 | 38.6 | |
| Unspecified | 9.1 | 8.5 | |
| Menopausal status (%) | |||
| Postmenopausal | 93.5 | 92.8 | 0.80 |
| Perimenopausal | 6.5 | 7.2 | |
| Time from menopause to study entry [mean (SD)], y | 9.9 (9.5) | 9.4 (8.5) | 0.51 |
NOTE: Continuous variables were tested with paired t test, and categorical variables are tested with McNemar's paired χ2 test.
*
Tumor stage was an exact matching criterion.