Table 2. Proliferation (Ki67), oestrogen receptor alpha (ERα) and progesterone receptor (PgR) expression in samples of breast epithelium taken from women at population risk of breast cancer undergoing removal of a fibroadenoma, from BRCA1 or BRCA2 mutation carriers undergoing prophylactic mastectomy (‘mutated’) or from women at high risk of breast cancer also undergoing prophylactic mastectomy or biopsy in women judged to be at increased risk of breast cancer either by family history or a previous history of cancer.
| Population risk | High risk | BRCA1+BRCA2 | BRCA1 only | ||
|---|---|---|---|---|---|
| n | 22 | 18 | 8 | 5 | |
| Ki67 (%) | |||||
| Median | 2.3 | 1.5 | 2.9 | 2.9 | nsdb |
| IQ rangea | 1.3–8.2 | 1.1–3.5 | 0.9–4.0 | 0.7–4.8 | |
| ERα (%) | |||||
| Median | 27.9 | 21.6 | 29.6 | 27.3 | nsd |
| IQ range | 16.9–32.9 | 17.3–35.8 | 12.2–35.2 | 13.2–36.0 | |
| PgR (%) | |||||
| Median | 24.8 | 20.6 | 19.5 | 15.3 | nsd |
| IQ range | 16.3–35.6 | 15.9–26.4 | 9.4–28.8 | 4.8–24.7 |
The figures represent the proportion of positively stained epithelial cells expressed as a percentage of the total number of cells counted.
a
IQ range – interquartile range.
b
nsd=no significant difference between the three risk groups by Kruskal–Wallis test.