Table 1:
Demographic and reproductive characteristics of 1,126 diagnosed invasive breast cancer cases and 2,106 controls from the Ghana Breast Health Study
| Controls N = 2,106 | Cases N = 1,126 | |||
|---|---|---|---|---|
| Study Population Characteristics | N | % | N | % |
| Age (years) | ||||
| <35 | 435 | 21 | 114 | 10 |
| 35–44 | 561 | 27 | 277 | 25 |
| 45–55 | 554 | 26 | 330 | 29 |
| ≥55 | 546 | 26 | 401 | 36 |
| Unknown | 10 | 4 | ||
| Study site | ||||
| Accra | 736 | 35 | 384 | 34 |
| Kumasi | 1370 | 65 | 742 | 66 |
| Age at menarche (years) | ||||
| Median age at menarche (IQR) | 15 (15–15) | 15 (15–15) | ||
| <15 | 568 | 30 | 266 | 27 |
| 15 | 548 | 29 | 255 | 26 |
| 16 | 383 | 20 | 223 | 23 |
| ≥17 | 395 | 21 | 228 | 23 |
| Unknown | 212 | 154 | ||
| Parity | ||||
| Median parity (IQR) | 4 (2–5) | 3 (2–5) | ||
| Nulliparous | 228 | 11 | 107 | 10 |
| 1–2 | 533 | 25 | 319 | 28 |
| 3–4 | 685 | 33 | 365 | 33 |
| ≥5 | 652 | 31 | 331 | 30 |
| Unknown | 8 | 4 | ||
| Age at first birth (years) | ||||
| Median age (IQR) | 20 (18–24) | 21 (19–25) | ||
| <19 | 555 | 31 | 235 | 25 |
| 19–21 | 510 | 28 | 265 | 28 |
| 22–25 | 412 | 23 | 260 | 27 |
| ≥26 | 322 | 18 | 197 | 21 |
| Unknown | 79 | 62 | ||
| Median breastfeeding per pregnancy (months) | ||||
| Median months(IQR) | 18 (15–24) | 18 (12–24) | ||
| <13 | 352 | 20 | 239 | 26 |
| 13–18 | 692 | 39 | 341 | 37 |
| ≥19 | 747 | 42 | 347 | 37 |
| Unknown | 87 | 92 | ||
| ER status | ||||
| Positive | 393 | 50 | ||
| Negative | 387 | 50 | ||
| Unknown | 346 | |||
| PR status | ||||
| Positive | 402 | 52 | ||
| Negative | 374 | 48 | ||
| Unknown | 350 | |||
| HER2 status | ||||
| Positive | 181 | 23 | ||
| Negative | 544 | 70 | ||
| Inconclusive | 54 | 7 | ||
| Unknown | 347 | |||
IQR = interquartile range. ER = oestrogen receptor. PR = progesterone receptor. HER2 = human epidermal growth factor receptor 2.