Table 1. Demographic information of study population by breast cancer status.
| Breast cancer cases (N = 149) | Disease-free controls (N = 42) | |
|---|---|---|
| Age | ||
| Mean (SD) | 57.4 (11.4) | 54.4 (12.4) |
| Self-reported Race | ||
| Black | 44 (29.5%) | 21 (50.0%) |
| White | 105 (70.5%) | 21 (50.0%) |
| BMI | ||
| Mean (SD) | 30.0 (7.89) | 29.7 (8.62) |
| Missing | 7 (4.7%) | 4 (9.5%) |
| Smoking Status | ||
| Never | 81 (54.4%) | 19 (45.2%) |
| Former | 46 (30.9%) | 12 (28.6%) |
| Current | 16 (10.7%) | 5 (11.9%) |
| Missing | 6 (4.0%) | 6 (14.3%) |
| Age at menarche (years) | ||
| Mean (SD) | 12.7 (1.42) | 12.7 (1.62) |
| Missing | 47 (31.5%) | 17 (40.5%) |
| Parity | ||
| No | 13 (8.7%) | 5 (11.9%) |
| Yes | 89 (59.7%) | 23 (54.8%) |
| Missing | 47 (31.5%) | 14 (33.3%) |
| ER | ||
| Negative | 64 (43.0%) | NA |
| Positive | 83 (55.7%) | NA |
| Missing | 2 (1.3%) | NA |
| HER2 | ||
| Negative | 119 (79.9%) | NA |
| Positive | 22 (14.8%) | NA |
| Missing | 8 (5.4%) | NA |
| Tumor grade | ||
| 1 | 12 (8.1%) | NA |
| 2 | 47 (31.5%) | NA |
| 3 | 69 (46.3%) | NA |
| Missing | 21 (14.1%) | NA |
| Treatment status at DNA collection | ||
| Pre-treatment | 47 (31.5%) | NA |
| Post-treatment | 102 (68.5%) | NA |
| Surgery only | 8 (7.8%) | NA |
| Chemotherapy only | 19 (18.6%) | NA |
| Radiotherapy only | 16 (15.7%) | NA |
| Both chemotherapy and radiotherapy | 37 (36.3%) | NA |
| Missing | 22 (21.6%) | NA |
| GrimAA | ||
| Mean (SD) | 0.59 (4.80) | -1.89 (5.93) |
| IEAA | ||
| Mean (SD) | 0.39 (4.22) | -1.33 (4.88) |
SD standard deviation; BMI Body mass index; ER estrogen receptor; HER2 human epidermal growth factor receptor 2; GrimAA GrimAge acceleration; IEAA Intrinsic epigenetic age acceleration; NA not applicable