Oestrogen receptor (ER) status is a good predictor of clinical response to hormonal therapies: the likelihood and level of response increases with higher levels of receptor expression6. The best response is in patients with a tumour that is positive for both ER and progesterone receptors (PR). Progesterone receptors are an independent predictor of response and indicate a functioning oestrogen receptor pathway. Immunohistochemistry is equal or superior to ligand binding assay for the prediction of response to hormonal therapy with greater sensitivity and requiring less tissue6. However, variability arises from pre-analytical handing, the choice of antibody, antigen retrieval methodology, use of controls, interpretation and scoring6.
Oestrogen receptor estimation in core biopsies correlates well with expression in excised tumours but the score on core biopsy is higher, presumably because of the tendency to sample the periphery of the tumour, where expression is greater4.
Overall rates of expression of oestrogen (ER) and progesterone receptors (PR)1:
|
ER+ |
ER- |
|
PR+ |
55% |
3% |
59% |
PR- |
20% |
22% |
44% |
|
75% |
25% |
|
The rate of expression increases with patient age and following the menopause6. Tamoxifen may reduce expression7.
Medullary carcinomas are usually negative for oestrogen receptors (positivity defined as >10% nuclei immunoreactive)2:
Typical medullary carcinoma |
0/13 |
Atypical medullary carcinoma |
3/24 |
Ductal carcinoma with medullary features |
4/23 |
Apocrine ductal carcinoma in situ is characteristically positive for androgen receptors but negative for oestrogen and progesterone receptors3:
33/34 |
|
2/35 |
|
1/34 |
Prolactin receptor is also expressed by breast tissue and tumours. Normal breast tissue shows consistent positivity of the luminal surface of epithelial cells, with negativity of the myoepithelial and stromal cells. Expression by tumours correlates with expression of oestrogen receptor but not with stage or tumour grade4:
fibrocystic disease |
4/84 |
fibroadenoma |
9/94 |
florid regular duct hyperplasia |
0/34 |
intraduct papillomas |
6/64 |
lactating adenoma |
2/24 |
duct ectasia |
2/34 |
gynaecomastia |
5/64 |
ductal carcinoma |
36/524 |
lobular carcinoma |
3/44 |
tubular carcinoma |
1/14 |
mucinous carcinoma |
1/14 |
squamous carcinoma |
0/14 |
Core biopsies are generally a good indicator of oestrogen receptor status:
|
by Quick Score |
positive vs negative (determines anti-oestrogen therapy) |
|
core versus wide local excision |
48/59 |
55/59 |
|
core versus mastectomy |
20/27 |
24/27 |
|
overall |
68/86 |
79/86 |
|
The risk of brain metastases correlates with negativity for oestrogen receptors, along with high grade, expression of CK5/6, epidermal growth factor receptor and HER28.
References
5 Graham AD, Loane J. Oestrogen receptor assays in breast cancer: correlation between core biopsies and resection specimens. Pathological Society July 2004.
7 Verghese et al. Mitotic rate, ER and bcl-2 expression in short term Tamoxifen treated breast cancer. J Pathol 2001:193(suppl):31A.
This page last revised 23.9.2006.
©SMUHT/PW Bishop