Immunostaining of estrogen receptor, progesterone receptor, MIB1 antigen, and c-erbB-2 oncoprotein in cytologic specimens: a simplified method with formalin fixation

Immunocytochemical expression of Ki-67/p16 in normal, atypical, and neoplastic cells in urine cytology using BD SurePath™ as preparation method

OBJECTIVE

The objective of this study was to investigate the expression of Ki-67/p16 in urothelial cells in cytological material.

MATERIALS AND METHODS

There were 142 urines including normal controls, anonymous rest urine, controls after treatment for urothelial carcinoma (UC) and newly diagnosed UC. Immunocytochemistry for ki-67/p16 dual staining kit was performed on all specimens.

RESULTS

Eight high-grade UC and six anonymous specimens showed dual positivity. None of the low-grade UC or the control specimens after treated UC showed dual staining. Fifteen of 84 (17.8%) symptomatic cases were negative for both markers, and 59/84 (70.2%) showed positivity for both but not dual staining. Twenty-seven of 84 cases were positive for either Ki-67 (n = 22) or p16 (n = 5). Normal controls and benign specimens were negative for p16.

CONCLUSIONS

Co-expression of p16/Ki-67 in the same cells was found in 16.6% of the cases. All were high grade, and co-expression seems to have limited practical impact as an additional marker in urine cytology. Any positivity for p16 alone strongly indicates malignancy. Negative p16 accompanied by a positive Ki-67 rate at 5% or more could be considered as an additional marker for further clinical follow-up. Both markers, co-expressed and separate, can give additional information in follow-up patients after treatment for UC.

When tissue antigens and antibodies get along: revisiting the technical aspects of immunohistochemistry--the red, brown, and blue technique

Once focused mainly on the characterization of neoplasms, immunohistochemistry (IHC) today is used in the investigation of a broad range of disease processes with applications in diagnosis, prognostication, therapeutic decisions to tailor treatment to an individual patient, and investigations into the pathogenesis of disease. This review addresses the technical aspects of immunohistochemistry (and, to a lesser extent, immunocytochemistry) with attention to the antigen-antibody reaction, optimal fixation techniques, tissue processing considerations, antigen retrieval methods, detection systems, selection and use of an autostainer, standardization and validation of IHC tests, preparation of proper tissue and reagent controls, tissue microarrays and other high-throughput systems, quality assurance/quality control measures, interpretation of the IHC reaction, and reporting of results. It is now more important than ever, with these sophisticated applications, to standardize the entire IHC process from tissue collection through interpretation and reporting to minimize variability among laboratories and to facilitate quantification and interlaboratory comparison of IHC results.

Systematic review on hormone receptor testing in breast cancer

Assessment of hormone receptors (estrogen and progesterone) helps to direct therapy for women with breast cancer. Immunohistochemistry is most commonly used to assess hormone receptor status and it is essential that these tests are performed accurately and reliably within and across laboratories. The overall purpose of this guideline is to improve the quality and accuracy of hormone receptor testing and its utility as a prognostic and predictive marker for invasive and in situ breast cancer. Medline, EMBASE, the Cochrane Database of Systematic Reviews, and abstracts from the San Antonio Breast Cancer Symposium were searched. An environmental scan of the internet and of international guideline developers and key organizations was performed. Preanalytic elements such as the collection, fixation, and storage of samples, and analytic elements such as selection of antibodies and scoring methods that seem to offer the best results for immunohistochemical assessment of hormone receptors are presented. Proficiency testing or quality assurance of immunohistochemistry is described.

Cancer care Ontario guideline recommendations for hormone receptor testing in breast cancer

Hormone receptor testing (oestrogen and progesterone) in breast cancer at the time of primary diagnosis is used to guide treatment decisions. Accurate and standardised testing methods are critical to ensure the proper classification of the patient's hormone receptor status. Recommendations were developed to improve the quality and accuracy of hormone receptor testing based on a systematic review conducted jointly by the American Society of Clinical Oncology/College of American Pathologists and Cancer Care Ontario's Program in Evidence-Based Care. Evidence-based recommendations were formulated to set standards for optimising immunohistochemistry in assessing hormone receptor status, as well as assuring quality and proficiency between and within laboratories. A formal external review was conducted to validate the relevance of these recommendations. It is anticipated that widespread adoption of these guidelines will further improve the accuracy of hormone receptor testing in Canada.

Optimal antigen retrieval for ethanol-fixed cytologic smears

BACKGROUND

Antigen retrieval, a crucial technique for immunostaining, is often carried out on formalin-fixed, paraffin-embedded (FFPE) tissue sections. The role of antigen retrieval in immunostaining of ethanol-fixed smears remains unclear. The authors evaluated the effects of 2 common antigen retrieval procedures, heat-induced antigen retrieval and protease-induced antigen retrieval, for immunostaining using a broad panel of antibodies.

METHODS

Papanicolaou-stained ethanol-fixed smears from 36 surgical specimens were immunostained with 43 antibodies. Three widely used heat-induced antigen retrieval solutions, namely, citrate buffer (pH 6.0 and pH 7.0) and ethylenediaminetetraacetic acid solution (pH 8.0) for heat-induced antigen retrieval, and pronase were used. The staining results were compared between the ethanol-fixed smears and the corresponding FFPE tissue sections.

RESULTS

Heat-induced antigen retrieval was essential for all the 9 antibodies examined against nuclear antigens, and for 7 of 26 antibodies against cytoplasmic and cell membrane antigens. Superior results were obtained using lower-pH heat-induced antigen retrieval solutions for ethanol-fixed smears than was the case for FFPE tissue sections; use of citrate buffer (pH 6.0) was optimal for most antibodies. For 17 antibodies against cytoplasmic/cell membrane antigens, satisfactory results were obtained even without antigen retrieval on the ethanol-fixed smears, whereas antigen retrieval was necessary for detection on the FFPE tissue sections. Protease-induced antigen retrieval frequently exerted deleterious effects on ethanol-fixed smears. Despite antigen retrieval, detection of 2 lymphocytic markers failed on ethanol-fixed smears. This limitation was overcome by heat-induced antigen retrieval on formalin vapor-fixed smears.

CONCLUSIONS

In ethanol-fixed smears, most of the antibodies can be immunostained successfully without antigen retrieval treatment or mild heat-induced antigen retrieval using citrate buffer (pH 6.0). The optimal antigen retrieval condition for each antibody must be individually determined.

Antigen retrieval immunohistochemistry: review and future prospects in research and diagnosis over two decades

As a review for the 20th anniversary of publishing the antigen retrieval (AR) technique in this journal, the authors intend briefly to summarize developments in AR-immunohistochemistry (IHC)-based research and diagnostics, with particular emphasis on current challenges and future research directions. Over the past 20 years, the efforts of many different investigators have coalesced in extending the AR approach to all areas of anatomic pathology diagnosis and research and further have led to AR-based protein extraction techniques and tissue-based proteomics. As a result, formalin-fixed paraffin-embedded (FFPE) archival tissue collections are now seen as a literal treasure of materials for clinical and translational research to an extent unimaginable just two decades ago. Further research in AR-IHC is likely to focus on tissue proteomics, developing a more efficient protocol for protein extraction from FFPE tissue based on the AR principle, and combining the proteomics approach with AR-IHC to establish a practical, sophisticated platform for identifying and using biomarkers in personalized medicine.

Liquid based material from fine needle aspirates from breast carcinomas offers the possibility of long-time storage without significant loss of immunoreactivity of estrogen and progesterone receptors

BACKGROUND

Estrogen receptor (ER) status and progesterone receptor (PgR) status are strong prognostic and predictive markers in breast carcinomas. Steroid receptors are fragile and optimal handling of both cytological and histological material, including fixation, is crucial. Liquid based material offers the possibility to prepare a number of slides from one lesion and is increasingly being used for immunocytochemistry. It also offers the possibility to prepare several smears and to store these at different temperatures as well as storing residual material in the liquid.

MATERIALS AND METHODS

The samples consisted of fine needle aspirate material from 53 breast carcinomas. Direct smears and liquid based preparations were used in parallel for immunocytochemical detection of ER and PgR receptor status. Slides from liquid suspensions were stored at -20°C and -74°C for 3 and 6 months, respectively. Direct smears were fixed primarily in 4% formalin. Liquid based specimens were post-fixed in 4% formalin. All specimens were subjected to microwave-stimulated epitope retrieval. Antibody concentrations were ER 1:150 and PgR 1:200 for both preparation methods. The immunostaining program was identical for both the methods.

RESULTS

Liquid based specimens had a statistically non-significant higher percentage of positive cases compared to direct smears. Specimens prepared from liquid suspensions and stored at -20°C and -74°C for 3 and 6 months, respectively, showed a virtually unchanged ER and PgR reactivity (P = 0.002).

CONCLUSIONS

Liquid suspensions and liquid based slide preparations seem to offer an optimal pre-fixation and preservation of ER/PgR in breast carcinoma cells. Post-fixation with 4% formalin followed by microwave-stimulated epitope retrieval before immunostaining is recommended. Long-time storage of liquid based specimens at -20°C or -74°C for at least 6 months without significant loss of immunoreactivity is feasible. They may be used as internal positive and negative controls.

Histological grading of breast cancer on needle core biopsy: the role of immunohistochemical assessment of proliferation

Aims

Histological grade assessed on needle core biopsy (NCB) moderately concurs with the grade in the surgical excision specimen (SES) (κ-values between 0.35 and 0.65). A major cause of the discrepancy is underestimation of mitoses in the NCB specimen. The aim was to determine the best method of assessing proliferation on NCB.

Methods and results

Proliferative activity of 101 invasive carcinomas of the breast on NCB and SES was assessed using mitotic counts on routine haematoxylin and eosin (H&E) sections and immunohistochemical markers Mib-1 and phosphorylated histone H3 (PPH3). H&E mitotic count in SES was considered as the gold standard. H&E mitotic count was found to be underestimated on NCB when compared with that in SES (P < 0.001), but no significant difference was detected between NCB and SES regarding Mib-1 (P = 0.13) or PPH3 (P = 0.073). Using receiver–operating characteristic curve, Mib-1 on NCB was found to agree with the gold standard significantly better than routine H&E on NCB.

Conclusions

Immunohistochemical markers in NCB showed better concordance with H&E mitotic count in SES (gold standard) than routine H&E mitotic count in NCB. Further refinement of cut-offs and scoring methods is needed.

Determination of HER-2 status on FNAC material from breast carcinomas using in situ hybridization with dual chromogen visualization with silver enhancement (dual SISH)

During the last years, HER-2 status kits and protocols for chromogen visualization of hybridization signals have come on the market. The first generation using chromogen visualization used single color probes. The second generation, now emerging on the market, uses dual chromogen visualization. The aim of this study has been to test a new dual color chromogen kit (Ventana INFORM HER2 Dual Colour ISH Roche^®) and compare the results with our in-house method(s). The material consisted primarily of cytological material from invasive breast carcinomas in 49 women. Dual SISH was done on all 49 cytological and histological specimens. The histological specimens were treated according to the manufacturer’s recommendations. The procedure was modified in several steps in order to adapt it to the cytological material. Hybridization failed in two cytological specimens. Dual SISH showed concordant results on cytological and histological material as to amplified/not amplified. The included cases had the same HER-2 expression in the invasive and the in situ components on histology. Four IDC showed HER-2 amplification (8.5%). Polysomy was found in two cases. All dual SISH results except for one concurred with the results of the in-house method(s) (1/47=2.1%). The dual SISH is suitable for cytological examination of HER-2 status. The protocol must be optimized for cytological material.

Application of immunohistochemistry to cytology

CONTEXT

The uses of monoclonal antibodies via immunochemistry have been reported frequently within the literature using various methodologies with applications to cytology specimens. The direct application of immunochemistry to cytology may have a variety of pitfalls that the general pathologist familiar with its application to histology may be unaware of when applying it prospectively to patient specimens.

OBJECTIVE

To review common pitfalls when applying immunochemistry to cytology specimens and to suggest approaches to the more common differential dilemmas that apply to a variety of cytology specimens that could be seen in a general pathology practice.

DATA SOURCES

The authors' own experiences of applying immunochemistry to cytopathology specimens within an academic setting along with supportive data from the literature.

CONCLUSIONS

Immunochemistry can be used to increase the predictability of a cytology diagnosis if care is taken with the cytology sample preparation methodology and there is judicious use of select monoclonal antibody panels to support a specific cytology diagnosis. Up-to-date evidence-based antibody databases should be used when selecting antibody panels.

Fine needle aspiration for evaluation of breast masses

PURPOSE OF REVIEW

Fine needle aspiration has been used for many years as a diagnostic tool for breast lesions, with high sensitivity and specificity. There is controversy as to whether this technique should be replaced by other diagnostic procedures such as core biopsy. This review aims to re-evaluate the usefulness of breast fine needle aspiration.

RECENT FINDINGS

During the past 10 years many institutions have replaced fine needle aspiration by core biopsy and related techniques such as vacuum-assisted core biopsy and advanced breast biopsy instrument action. Other institutions continue to use fine needle aspiration as a first line of investigation for breast lesions. This technique is especially useful in radiologically benign lesions and when combined with image guidance. The use of the 'triple test' (combined cytologic, clinical and radiologic findings) decreases false-negative and false-positive results.

SUMMARY

Fine needle aspiration continues to be an acceptable and reliable procedure for the preoperative diagnosis of breast lesions, particularly in developing countries, and when used as part of the 'triple test'. Accurate diagnosis requires experience in both aspiration technique and specimen interpretation. Clinicians should be mindful of the limitations of the technique. The choice between fine needle aspiration and core biopsy should be individualized for the patient.

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.

Utility of cytologic specimens in the evaluation of prognostic and predictive factors of breast cancer: Current issues and future directions

Although numerous biological and molecular markers of breast cancer have been identified over the past two decades, traditional factors such as estrogen receptor (ER), progesterone receptor (PR), and HER-2 remain among the most useful indicators of prognosis and therapeutic response to treatment. These markers can be reliably evaluated in cytologic specimens, particularly in fine-needle aspirates (FNA) of primary or metastatic breast cancer. Accurate assessment of ER, PR, and HER-2 is critical in the treatment of breast cancer patients. A review of the literature, however, shows considerable interlaboratory variability in the detection of these markers and reporting of the test results. Because therapies are now being directed toward individual molecular targets, there is a need for increased standardization of such analyses. Current practices should follow consensus recommendations set by the College of American Pathologists and the American Society for Clinical Oncology, and the results should be monitored through quality-assurance programs. The utility of cytologic specimens of breast lesions is also not limited to evaluation of individual prognostic and predictive factors. Cytologic specimens have been used successfully for genomic and proteomic studies. Such investigational studies are under way and offer great potential for revolutionizing the prediction of patient outcomes and disease response to therapy, as well as assessment of risk of developing breast cancer.

MIB-1 expression in cervical Papanicolaou tests correlates with dysplasia in subsequent cervical biopsies

Ki-67 nuclear antigen is present in proliferating cells. MIB-1 antibody, raised to the recombinant part of the Ki-67 antigen, is a widely used biologic marker to assess cell proliferation. Ki-67 expression is normally observed in parabasal and basal cells in the cervix. With increasing severity of dysplasia, MIB-1 labeling is seen in cells of the superficial layers of cervical epithelium, which are exfoliated. The purpose of this study was to determine the sensitivity and specificity of presence of MIB-1-positive cells in Papanicolaou tests for predicting cervical neoplasia, condyloma, or both, on follow up. Using microwave antigen retrieval method, 49 air-dried cervical smears in two-smear cases were evaluated with immunostaining with MIB-1 monoclonal antibody. Presence of MIB-1 positivity was arbitrarily set at > or = 4 MIB-1 immunoreactive cells in each smear. The degree of positive staining was correlated with the cytologic diagnoses, subsequent colposcopy-directed biopsies, endocervical curettage, and/or cytologic follow ups. Follow-up findings correlated with cytology in 33 cases (67%), with MIB-1 positivity in 35 cases (71%). Three cases with positive follow ups were missed by cytology but detected by MIB-1 staining, and three cases were missed by MIB-1 but detected by cytology. Both cytology and MIB-1 staining failed to detect a subsequent cervical lesion in two cases, and in six cases each, an abnormal finding was not substantiated on follow ups. MIB-1 immunostaining is a powerful technique for evaluating gynecologic smears and is as equally sensitive and specific as cervical cytology. It is able to identify cervical disease overlooked by cytologic screening; therefore, it may serve as an adjunct and complimentary tool to cervical cytology.

Biologic markers in ductal carcinoma in situ and concurrent infiltrating carcinoma. A comparison of eight contemporary grading systems

The relevance of 8 contemporary classification and grading systems for ductal carcinoma in situ (DCIS) of the breast was examined in 100 tumors by comparing DCIS grade with grade of the concurrent infiltrating ductal carcinoma (IDC). Besides tumor size and nodal status, the immunohistochemical parameters in both lesions were compared, including estrogen receptor, progesterone receptor, c-erbB-2 protein, E-cadherin, vimentin, Ki-67 (MIB1), and p27. Nuclear grading of DCIS alone or in combination with architectural pattern and necrosis showed the best correlation with grade of the invasive component. There also was a positive correlation between every biologic marker expressed in DCIS and in the concurrent IDC, supporting a clonal relationship. Biologic markers varied between the different grades of DCIS. DCIS is heterogeneous, and the progression of DCIS to IDC may be from low-grade DCIS to low-grade IDC and high-grade DCIS to high-grade IDC. This concept is different from the conventional model held for intraepithelial neoplasia in the cervix, vulva, vagina, and skin, in which there is increasing severity of in situ atypia (dysplasia) before the development of stromal invasion.

Value of Ki67 immunostain in identification of malignancy in serous effusions

The distinction between malignant and benign serous effusions continues to be a challenging and a frequent problem to cytopathologists. Recently, immunostains employing various antibodies have improved the diagnostic accuracy of malignant effusions. We investigated the usefulness of Ki67 (MIB1) antigen immunostaining in the evaluation and diagnosis of malignant serous effusions. Cell block sections from a total of 54 cases of serous effusions cytologically diagnosed as malignant (28), suspicious (6), and benign (20) were immunostained with MIB1 monoclonal antibody to the Ki67 nuclear proliferation antigen according to the avidin-biotin immunoperoxidase method. The patients were 30 women and 24 men with an average age of 58 yr. Ki67 (MIB1) immunostain labeling index (LI) values were higher than 20% in 23 of 28 (82%) cytologically malignant, in 3 of 6 (50%) suspicious, and in 1 of 20 (5%) benign/reactive. Further investigation revealed histologic, radiologic, and/or clinical evidence of malignancy in the 3 suspicious (but not in the benign/reactive) cases with Ki67 LI values higher than 20%. Correlation between Ki67 LI (> 20%) and cytologic effusion type (benign, suspicious, or malignant) was statistically significant (P < 0.0001). Ki67 immunostaining has value as an adjunct testing to cytomorphology and other immunostains in distinguishing benign from malignant effusions. The addition of Ki67 immunostaining to conventional cytology appears more sensitive than cytomorphology alone and may assist in arriving at accurate diagnoses in suspicious cases with inconclusive cytomorphologic features.