Immunohistochemical demonstration of oestrogen and progesterone receptors: correlation of standards achieved on in house tumours with that achieved on external quality assessment material in over 150 laboratories from 26 countries

摘要: Aims—To investigate the sensitivity of immunohistochemical (IHC) assays for oestrogen receptors (ER) and progesterone (PR) achieved by laboratories on breast tumours fixed processed in their own department, to compare this with degree they achieve circulated as part an external quality assessment (EQA) programme. Methods—On 10 occasions between April 1994 June 1998, histological sections from cancers showing various degrees expression ER PR were IHC staining participating UK national scheme immunocytochemistry (UK NEQAS-ICC). The these tumours, addition that participants (in house tumours), was assessed a panel four assessors, using established NEQAS-ICC scoring system. For selected run, evaluated means semiquantitative quick score method. Results—Although scores awarded generally higher than those NEQAS there also significant positive correlation two sets scores. Using method evaluation one runs, 47% classified having high expression. Of remaining cases, proportion initially only low or medium found have when stained organising laboratory. centre's routine assay hormonal be 90–100% efficient achieving optimal demonstration over 150 different laboratories. Conclusions—The results obtained provides evidence view EQA material are accurate indicators laboratory performance. Although most adequately detected receptor expression, large participants' being had centre. efficiency optimally demonstrating shows variations fixation tissue preparation not limiting factors preventing demonstration. Key Words: immunohistochemistry •