Table 6

The degree of oestrogen receptor (ER) expression of 152 tumours from 152 laboratories participating in assessment run 41, as defined by the participants' IHC assays and the UK NEQAS organising laboratory's IHC assay

Participant laboratoryOrganising laboratoryLevel of concordance
Degree of ER expressionn%n%n%% of total κ Valuep Value
ICH, immunohistochemistry; NA, not applicable.
High expressing tumours (quick scores of 7 and 6)7851.312380.97255.847.4−0.091 0.043
Medium expressing tumours (quick scores of 5 and 4)4227.61912.5713.04.6−0.495< 0.0001
Low expressing tumours (quick scores of 3 and 2)2415.874.6310.72.0−0.316< 0.0001
Negative tumours (quick scores of 0)85.332.0337.52.0NANA
All tumours (quick scores the same, within ± 1 mark)9663.263.2−0.026 0.291