Frequency of oestrogen and progesterone receptor positivity by immunohistochemical analysis in 7016 breast carcinomas: correlation with patient age, assay sensitivity, threshold value, and mammographic screening

Of the parameters investigated, patient age and IHC assay sensitivity were found to be the main variables influencing the frequency of receptor positivity. We recommend the range of receptor values obtained by laboratories achieving high assay sensitivity as a useful guide against which all laboratories can gauge their own results.