TABLE 11.

Assessment of oestrogen and progesterone receptors by Allred quick scoring (QS) system (4).

Average intensity	Points
Negative	0
Weak	1
Intermediate	2
Strong	3
Proportion of positive nuclei	Points
No	0
<1%	1
1–10%	2
10%–1/3	3
1/3–2/3	4
>2/3	5

The sum of the two subscores will give the total score. Possible values: 0, 2–8. (Response to endocrine therapy is expected for a score >2, and the response is expected to increase proportionally with the score). In theory, ER (PR) status can be Allred+ (Allred QS > 2) with <1% staining (<1% 2+, Allred QS 3 or <1% 3+, Allred QS 4), these are interpreted as negative. If recurrent or metastatic tumours are examined, steroid hormone receptor assessment should be repeated. Pathology departments performing predictive immunohistochemical tests are expected to participate in an external quality assurance programme and achieve appropriate qualification. The use of an external control tissue is recommended, and it is advisable to select a block for the immunohistochemical reaction that includes an internal control.