Breast biopsy ER and PR receptors
Keywords: Breast biopsy - oestrogen receptors (ER) and progesterone receptors (PR)
Specimen: |
Formalin-fixed paraffin embedded breast tissue. For optimum results tissues should be sliced to facilitate fixation.
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Method: |
Immunohistochemical staining of processed tissue with positive and negative controls.
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Application: |
To determine if tumours are potentially responsive to anti-oestrogen treatment.
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Interpretation: |
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Oestrogen receptor (ER) and progesterone receptor (PR) staining are seen in the nucleus.
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A positive score is recorded where >10% of nuclei show at least weak expression for PR and ER on immunohistochemical staining.
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Alternatively a combined score of staining distribution and density (Quick score) may be used as follows:
Staining 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.
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A score of zero indicates that endocrine treatments will be ineffective.
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A score of 2 or 3 indicates a small (20%) chance of response.
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A score of 4 to 6 indicates an even (50%) chance of response.
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A score of 7 or 8 indicates a good (75%) chance of response.
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Where progesterone receptor content has also been determined, endocrine treatment is considered appropriate for patients with low oestrogen receptor, but high progesterone receptor scores.
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Reference: |
Leake R et al. J Clin Pathol 2000; 53: 634-635.
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