Estrogen receptor studies in breast cancer based on histological material. Correlation with results from needle biopsy aspirates and pS2 protein determination

: Oestrogen receptor analyzed in archive, histologic specimens from 57 breast cancers showed a concordance with determination in fresh material of 50 to 60%. This means that about half of the oestrogen receptor positive tumours are "lost" when using histologic specimens. pS2 protein is an indirect marker of a functioning oestrogen receptor and was demonstrated in 84% of the carcinomas, including 15 that were oestrogen receptor positive in cytologic material, but negative in histologic specimens. In cases where only histologic specimens are available for receptor analysis, additional determination of pS2 protein may be useful.