Immunocytochemical staining of estrogen receptor in paraffin sections of human breast cancer by use of monoclonal antibody: comparison with that in frozen sections.

Abstract

Estrogen receptor (ER) in human breast cancer tissues was demonstrated in paraffin sections as well as in frozen sections by immunoperoxidase methods using monoclonal antibody (H222) against ER. The avidin-biotin-peroxidase complex method was used for the paraffin sections fixed in cold buffered formalin, and the peroxidase-antiperoxidase method was used for the fixed frozen sections. The results were compared with the ER content in the respective tumor tissue determined by dextran-coated charcoal assay. The specific staining for ER was located exclusively in the nuclei of cancer cells in both paraffin and frozen sections. Differences in the intensity and distribution of nuclear staining within a section were often observed, suggesting heterogeneity of the ER content of individual breast cancer cells. In 24 breast cancer tissues studied simultaneously by both paraffin and frozen section methods, 21 (88%) showed similar evaluation of the presence of ER. (6).In order to circumvent these disadvantages of the current ER assay, many immunocytochemical methods using antiestradiol antibody (7-11) and cytochemical methods using fluorescein-or peroxidase-labeled estradiol (12-15) have been proposed. However, sucrose gradient analysis revealed that the antibodies against estradiol do not necessarily detect the estradiol-ER complex (16). In addition, affinity of the estradiol-conjugate for ER was shown to be extremely low when compared with that of free estradiol (17)(18)(19). Although these published methods were aimed at visualizing the specific binding of estrogen to ER, the methods of tissue preparation used in these studies could not prevent the loss of ER through diffusion or the reduced ability of estrogen to bind to its receptor (20). Therefore, it is reasonable to conclude that the stains obtained by these immunocytochemical and cytochemical methods are not specific for ER (16)(17)(18)(19)(20).Recently, monoclonal antibodies to human ER were developed by Greene et al. (21) and Miller et al. (22). By use of these monoclonal antibodies against ER, King and Greene first demonstrated ER in frozen tissue sections prepared from human breast cancer and other sources (23). These monoclonal antibodies are highly specific for ER and could serve as a more reliable probe for detecting ER in tissues. However, frozen sections have limitations in their use for detailed examination of tumor morphology and for retrospective studies.In this study, methods were developed to demonstrate ER in cold formalin-fixed paraffin sections as well as in frozen sections of human breast cancer tissues by use ofone of these monoclonal antibodies. The utility of immunocytochemical staining of ER was evaluated by comparing the results with the results of determining ER content by the dextran-coated charcoal (DCC) assay. MATERIALS AND METHODSBreast Cancer Tissues. One hundred and thirteen breast cancer tumors (104 primary and 9 metastatic tumor tissues) were obtained at surgery at the National Cancer Center Hospital and Keio University Hosp...

Specific expression of the pS2 gene in subclasses of breast cancers in comparison with expression of the estrogen and progesterone receptors and the oncogene ERBB2.

“…In contrast to the specific ER ICA immunoperoxidase staining that appeared to be exclusively nuclear (Fig. 3B), in agreement with reports (15,16), the pS2 protein staining was cytoplasmic in breast cancer and metastatic node sections (Fig. 3 A, E, and F).…”

Pregnancy and the risk of breast cancer

“…In the postmenopausal breast, when circulating estrogen levels are low, there was marked involution of the TDLU and levels of ERa mRNA were low, but ERa and PR protein was common in luminal epithelial cells (Bartow 1998). A few smaller studies also exist which provide both supporting and conflicting observations (Petersen et al 1987, Jacquemier et al 1990, Ricketts et al 1991, Williams et al 1991, Clarke et al 1997, Keeling et al 2000, but it is difficult to draw general conclusions across these studies on the ERa expression pattern in the normal human breast due to differences in methodologies (Shimada et al 1985, Ricketts et al 1991). However, it seems clear that 6-15% of normal human breast epithelial cells stain positively for ERa.…”

Triple-negative breast cancer types exhibit a distinct poor clinical characteristic in lymph node-negative Chinese patients

“…ER and PR antibodies were purchased from Dako (clones ER 1D5 and PR 636). The two antibodies were evaluated by an avidin-biotin-peroxidase complex (ABC) assay as described by Shimada et al (22). ER and PR were considered as positive in breast cancer cells if the positive nuclei number was >10%.…”