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Stability of oestrogen and progesterone receptor antigenicity in formalin‐fixed paraffin‐embedded breast cancer tissue over time
Author(s) -
Ehinger Anna,
Bendahl Pärola,
Rydén Lisa,
Fernö Mårten,
Alkner Sara
Publication year - 2018
Publication title -
apmis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.909
H-Index - 88
eISSN - 1600-0463
pISSN - 0903-4641
DOI - 10.1111/apm.12884
Subject(s) - immunohistochemistry , tissue microarray , breast cancer , progesterone receptor , antigenicity , oestrogen receptor , biomarker , cancer , pathology , biology , receptor , estrogen receptor , medicine , cancer research , antibody , immunology , biochemistry
Use of archived formalin‐fixed paraffin‐embedded ( FFPE ) tissue is a standard method for evaluation of proposed prognostic and predictive tumour markers. However, little is known of the preservation of biomarker expression in old FFPE tumour blocks. We investigate the quality of immunohistochemical ( IHC ) oestrogen ( ER ) and progesterone receptor ( PR ) evaluation in FFPE tissue over time (1978–2000) using a large breast cancer tissue microarray (N = 573) with access to receptor analyses in cytosol ( CYT ) at diagnosis, coexpression of other biomarkers and follow‐up data. We found a good correlation between ER analysed with CYT at diagnosis and ER analysed with IHC in archived FFPE tissue from the same tumour. ER evaluation did not seem to be affected by tissue storage time. Nor was there any time‐dependent difference in ER IHC correlation with other biomarkers ( HER 2, Ki67) or survival. Discordant cases were more often classified as ER ‐positive with IHC than with CYT . For PR , however, we found an increased correlation between methods in more recent time periods. This may possibly be explained by more reliable PR IHC results in newer samples, although other explanations may also contribute. Our results indicate stable ER expression in FFPE tissue archived for up to 40 years.