Prognostic and diagnostic implications of estrogen and progesterone receptor assays in cytology

Signal amplification in immunohistochemistry: loose-jointed deformable heteropolymeric HRP conjugates vs. linear polymer backbone HRP conjugates

Improvements in reagents and protocols for immunohistochemistry have led to increased sensitivity of detection systems. A significant level of signal amplification was achieved by the chain-polymer conjugate technology utilizing enzyme-labeled inert "backbone" molecule of dextran (Dako). However, the relatively large size of the dextran molecule in aqueous phase appears to create spatial hindrance compromising the penetrative ability of the detection reagent. Novel AmpliStain™ detection systems (SDT GmbH, Baesweiler, Germany) seem to overcome these constraints offering a more compact and deformable conjugate design that facilitates agile penetration through the narrowest diffusion pathways in tissue sections. Here, we compared the level of signal amplification achievable with AmpliStain™-HRP (SDT) and EnVision™+-HRP (Dako). Our results show that the AmpliStain™-HRP systems allow higher dilutions of primary antibodies in both immunohistochemistry and ELISA. Compared with EnVision™+, anti-mouse AmpliStain™ enables at least three times more sensitive detection of mouse antibodies, whereas anti-rabbit AmpliStain™ is ten times more sensitive than anti-rabbit EnVision™+.

Optimal fixation conditions for immunocytochemical analysis of estrogen receptor in cytologic specimens of breast carcinoma

BACKGROUND

The techniques for immunostaining estrogen receptor (ER) in cytologic specimens have varied, as have the detection rates. The authors compared various fixation methods for their effect on ER detection in cytologic smears of breast carcinoma.

METHODS

Smears were prepared by gently scraping the cut surfaces of 47 resected breast carcinoma specimens and placing immediately in 1 of the following conditions: 1) a sequence of 10% formalin-methanol-acetone fixatives at -20 degrees C (Abbott method); 2) 10% formalin at room temperature; and 3) Carnoy's fixative at room temperature and then Papanicolaou stained (Carnoy's-Pap). Destaining of Carnoy's-Pap smears (Carnoy's-dPap) was initially attempted before ER staining. One set of smears was also air-dried for 3 minutes before using the Abbott method. Smears and corresponding tissue sections were immunostained with anti-ER antibody 6F11 using a similar protocol except for antigen retrieval, which was not initially applied on cytologic slides. All the ER-negative smears that had been fixed with 10% formalin or Carnoy's-Pap were restained after antigen retrieval. Agreement between cytologic and histologic findings was expressed by both concordance and the kappa coefficient.

RESULTS

ER detection in smears processed with the Abbott method correlated best with findings from tissue samples, with an overall correlation of 91.5% (kappa = 0.80). Findings from air-dried smears were less optimal (concordance, 84.4%; kappa = 0.65), followed by Carnoy's-Pap (concordance, 71.4%; kappa = 0.45), formalin (concordance, 31%; kappa = 0.05), and Carnoy's-dPap (concordance, 29.4%; kappa = 0.04). Antigen retrieval converted most of the ER-negative smears to positive (18 of 20 smears in formalin and 6 of 8 smears in Carnoy's-Pap), leading to a final concordance of 93% and kappa = 0.83 for both conditions. Antigen retrieval also led to stronger staining intensity without causing false positivity.

CONCLUSIONS

Antigen retrieval was found to greatly improve ER immunodetectability and staining intensity in formalin-fixed and Carnoy's-Pap smears. The former may offer an alternative to the Abbott method because of its easiness and the latter can be reliably used in archival Pap-stained smears for retrospective analysis of ER. Air-drying, destaining Pap smear, and fixation in formalin or Carnoy's-Pap without antigen retrieval are not recommended.

The expanding role of pathologists in the diagnosis and management of breast cancer: Worldwide Excellence in Breast Pathology Program

Pathology is the study of human illness and it involves the morphologic and biologic recognition of abnormalities that are associated with a disease. Breast pathology represents an excellent example of this discipline. By providing diagnostic information and by characterizing the biologic behavior of a breast lesion, a pathologist plays a critical role in a patient's life. Any mistake in this exercise is associated with serious consequences. In addition, there are many unresolved issues in breast pathology, which contribute to our limited understanding of the biology of breast cancer, variability in diagnostic criteria, and significant diversity in breast cancer management and therapy. Furthermore, breast pathology has remained an underrecognized discipline, and its importance in diagnosis and disease management is not fully realized. In order to better serve our patients, particularly medically underserved women and those living in countries with limited resources, we must place emphasis on effectively using the talent and expertise of pathologists around the globe. For example, to provide a cost-effective way to diagnose breast cancer, particularly at advanced stages, pathologists can sample lesions by fine-needle aspiration biopsy (FNAB), stain the resulting smears, and provide an immediate bedside diagnosis. This is a valid contribution; however, this exercise requires the availability of a pathologist with experience in breast cytopathology. Alternatively the pathologist may seek consultations from more experienced pathologists. Developing strategies to better recognize the importance of high-quality breast pathology services and to train qualified and innovative breast pathologists is an ambitious task. The proposed Worldwide Excellence in Breast Pathology Program may provide such an opportunity.

Estrogen and progesterone hormone receptor status in breast carcinoma: comparison of immunocytochemistry and immunohistochemistry

We evaluated the correlation between histologic and cytologic specimens in the determination of estrogen receptor (ER) and progesterone receptor (PR) status in breast carcinoma and investigated the causes of clinically significant discrepancies. We analyzed 70 immunoassays for ER and 60 for PR from 71 patients with breast carcinoma. Concordance between cytology and histology was 89% for ER and 63% for PR using scores from pathology reports. Concordance between cytology and histology was 98% for ER and 91% for PR using consensus scores (obtained after reevaluation by the team of pathologists). Thirty of 130 (23%) tests had clinically relevant discrepancies, 53% of which were caused by wrong interpretation of cytologic findings, 10% by wrong interpretation of histologic findings, 17% by sampling error and 20% were not available for reevaluation. Wrong interpretation of the results for ER and PR status in cytology was a far more frequent cause of clinically relevant discrepancies than sampling errors. The use of strict criteria is recommended.

Activation of antimetastatic Nm23-H1 gene expression by estrogen and its alpha-receptor

Metastasis of various malignant cells is inversely related to the abundance of the Nm23-H1 protein. The role of estrogens in tumor metastasis has now been investigated by examining the effect of E2 on the expression of the Nm23-H1 gene. Three human breast carcinoma cell lines, in which endogenous ERalpha is expressed at different levels, were used as a tool to assess the role of ERalpha in Nm23-H1 gene-mediated metastasis. E2 induced time-dependent increases in the abundance of Nm23-H1 mRNA and protein, with the extent of these effects correlating with the level of expression of ERalpha. E2 induced a marked decrease in the invasive activity of MCF-7 and BT-474 cells but had no effect on BCM-1 cells, which had virtually no ERalpha. Consistent with these results, the ER-mediated Nm23-H1 promoter activity was inhibited 3-fold by the E2 antagonist, ICI 182,780. Deletion analysis of the promoter region of the Nm23-H1 gene identified a positive estrogen-responsive element located in -108/-94. ER protein bound specifically to the -108/-79 fragment with high avidity. These results indicate that E2, acting through ERalpha, activated transcription of the Nm23-H1 gene via a positive estrogen-responsive element in the promoter region of the gene. These results suggest that E2 could suppress tumor metastasis by activating the expression of the Nm23-H1 gene.