Breast Biopsy - Oestrogen receptors (ER) and Progesterone receptors (PR)

Last updated: Wednesday, 28, November, 2007
Item Process
Specimen

Formalin-fixed paraffin embedded breast tissue. For optimum results tissues should be sliced to facilitate fixation.

Method

Immunohistochemical staining of processed tissue with positive and negative controls.

Application

To detirmine if tumours are potentially responsive to anti-oestrogen treatment.

Interpretation
  • Oestrogen receptor (ER) and progesterone receptor (PR) staining is seen in the nucleus.
  • A positive score is recorded where >10% of nuclei show at least weak expression for PR and ER on immunohistochemical staining.
  • Alternatively a combined score of staining distribution and density (Quick score) may be used as follows:

Stainig distribution:

% of positive nuclei         Score

0                                    0

<1%                              1

1-10%                            2

11-33%                          3

34-66%                          4

67-100%                        5

Staining intensity:

Intensity                   Score

No staining                 0

Weak staining             1

Moderate staining        2

Strong staining            3

The distribution and intensity of scored are added to give a score out of 8.

  • A score of zero indicates that endocrine treatments will be ineffective.
  • A score of 2 or 3 indicates a small (20%) chance of response.
  • A score of 4 to 6 indicates an even (50%) chance of response.
  • A score of 7 or 8 indicates a good (75%) chance of response.
  • Where progesterone receptor content has also been detirmined, endocrine treatment is considered appropriate for patients with low oestrogen receptor, but high progesterone receptor scores.
Reference

Leake R, Barnes D, Pinder S, et al. Immunohistochemical detection of sterioud receptors in breast cancer: a workin protocol. J Clin Pathol 53: 634-635, 2000