ER, PR, and Her2 immunocytochemistry on cell-transferred cytologic smears of primary and metastatic breast carcinomas: A Comparison Study With Formalin-Fixed Cell Blocks and Surgical Biopsies

Immunohistochemistry Applied to Breast Cytological Material

Fine-needle aspiration biopsies (FNABs) of the breast are minimally invasive procedures enabling the diagnosis of suspicious breast lesions. Unfortunately, they are often perceived as inferior to core-needle biopsies, namely because they are supposedly unable to differentiate between high-grade ductal carcinoma in situ and invasive carcinoma or provide material for ancillary testing. Several studies have shown, however, that FNAB samples, when handled properly, are indeed capable of providing sufficient and adequate material for ancillary testing, namely immunocytochemistry (ICC). We reviewed the published literature regarding the use of ICC for both diagnostic and theranostic uses in the different types of cytological samples obtained from FNABs of the breast, including smears, liquid-based cytology samples, and cellblocks. We found that p63 and 34βE12 show promise in aiding in the differential diagnosis between in situ and invasive lesions and that most other diagnostic markers may be used as in tissue. Regarding theranostic ICC markers, results vary between publications, but with care, these can successfully be performed in cytological samples. Air-dried smears should be avoided, and cellblocks are overall more versatile than cytology slides, enabling the evaluation of not only hormonal receptors and HER2 by ICC, but also of Ki-67. Particular attention should be paid to fixation and antigen retrieval procedures in all cases. We recommend that laboratories without experience perform short validation runs before adopting these techniques into clinical practice.

The initial hormone receptor/HER2 subtype is the main determinator of subtype discordance in advanced breast cancer: a study of the SONABRE registry

Purpose

The hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) are the main parameters in guiding systemic treatment choices in breast cancer, but can change during the disease course. This study aims to evaluate the biopsy rate and receptor subtype discordance rate in patients diagnosed with advanced breast cancer (ABC).

Methods

Patients diagnosed with ABC in seven hospitals in 2007–2018 were selected from the SOutheast Netherlands Advanced BREast cancer (SONABRE) registry. Multivariable logistic regression analyses were performed to identify factors influencing biopsy and discordance rates.

Results

Overall, 60% of 2854 patients had a biopsy of a metastatic site at diagnosis. One of the factors associated with a reduced biopsy rate was the HR + /HER2 + primary tumor subtype (versus HR + /HER2- subtype: OR = 0.68; 95% CI: 0.51–0.90). Among the 748 patients with a biopsy of the primary tumor and a metastatic site, the overall receptor discordance rate was 18%. This was the highest for the HR + /HER2 + primary tumor subtype, with 55%. In 624 patients with metachronous metastases, the HR + /HER2 + subtype remained the only predictor significantly related to a higher discordance rate, irrespective of prior (neo-)adjuvant therapies (OR = 7.49; 95% CI: 3.69–15.20).

Conclusion

The HR + /HER2 + subtype has the highest discordance rate, but the lowest biopsy rate of all four receptor subtypes. Prior systemic therapy was not independently related to subtype discordance. This study highlights the importance of obtaining a biopsy of metastatic disease, especially in the HR + /HER2 + subtype to determine the most optimal treatment strategy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10549-021-06472-5.

Rapid Cell Transfer by Means of Nylon Mesh to Improve Cellular Diagnosis: The Role of Immunocytochemistry

Immunocytochemistry (ICC) is an important ancillary technique in clinical cytology for not only identifying and characterizing tumor cells but also gaining prognostic or therapeutic information. Although cell blocks are often prepared for immunocytochemical evaluation of body cavity fluid and fine-needle aspiration specimens, they are not suitable for hypocellular samples. Liquid-based cytology can help prepare additional smears from residual cytological specimens. However, since conventional methods are used for nongynecological specimens in most laboratories, ICC is often limited by the number of cytological smears. Cell transfer methods permit to evaluate several immunocytochemical markers in a single cytological smear. Yet, these methods have some limitations; for example, they are time-consuming (about 3-40 h) and medium membranes with their attached cells are occasionally stretched or torn when peeled off the slides. Therefore, in an attempt to solve these problems, we developed a rapid and reliable cell transfer method using a nylon mesh. Our method requires no special equipment or reagent and can significantly reduce the turnaround time, as compared to previous methods.

Transferred-tissue Microarray for Fluorescence In Situ Hybridization Test for Human Epidermal Growth Factor Receptor 2 in Breast Cancer

CONTEXT

Human epidermal growth factor receptor 2 (HER2) status of breast carcinomas is usually determined by immunohistochemical (IHC) staining and, if the IHC results are equivocal, in situ hybridization (ISH). Multiple ISH tests are sometimes required for multiple primary or metastatic tumors. A method for multiplex ISH test on tissues from multiple blocks is helpful in these situations.

OBJECT

To evaluate the clinical application of transferred-tissue microarray (TTM) followed by a dual-probe HER2 fluorescence in situ hybridization (FISH).

DESIGN

A 3×3 TTM technique was successfully established using 152 invasive mammary carcinoma tissue fragments. To evaluate detection of HER2 positive tumors, this cohort was enriched with tumors with IHC scores of 2 and 3.

RESULTS

The HER2 FISH analyses revealed that all transferred-tissue fragments were adequate for determining HER2 amplification. Tissue loss was minimal and had no major adverse effects on interpretation of the test results. Of the 81 tumors with IHC scores of 3, 72 (88.8%) were positive for HER2 FISH. The remaining tumors were negative for HER2 FISH in both TTM and reflex whole tissue section. Finally, FISH results for tumors with IHC scores of 2 were compared between TTM and whole tissue section. Concordance was high in overall positivity/negativity (100%), HER2 copy number (97.5%), and HER2/CEP17 ratio (100%).

CONCLUSIONS

This novel technique is a reliable option for performing multiple HER2 FISH tests simultaneously in clinical and research-oriented settings with less tissue damage compared with conventional tissue microarray techniques.

Role of Immunocytochemistry in the Cytological Diagnosis of Pulmonary Tumors

Pulmonary cytology is a challenging diagnostic tool, and it is usually evaluated considering medical history and radiological findings in order to reach an accurate diagnosis. Since the majority of lung cancer patients have an advanced stage at diagnosis, a cytological specimen is frequently the only material available for diagnosis and further prognostic/predictive marker determination. Several types of specimens can be obtained from the respiratory system (including sputum, bronchoalveolar lavage, bronchial brushing, fine needle aspiration, and pleural fluid) with different technical preclinical management protocols and different diagnostic yields. Immunocytochemistry (ICC) has a pivotal role in the determination of diagnostic, prognostic, and predictive markers. Therefore, limited cytology samples are to be used with a cell-sparing approach, to allow both diagnostic ICC evaluation as well as predictive marker assessment by ICC or specific molecular assays. In this review, we describe the most common ICC markers used for the diagnosis and prognostic/predictive characterization of thoracic tumors in different cytological specimens.

Endobronchial Ultrasound-guided Transbronchial Needle Aspiration in the Diagnosis of Breast Cancer Thoracic Metastases and Detection of Receptor Discordance

BACKGROUND

Metastasis of breast cancer to mediastinal lymph nodes is common and biopsy of suspicious lesions can have important diagnostic, prognostic, and therapeutic implications, particularly with respect to tumor receptor status. Our aim was to show that endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) can be used for the diagnosis of metastatic breast cancer and demonstrate reliable receptor evaluation that can result in change of therapy.

METHODS

A retrospective review of consecutive adult patients undergoing EBUS-TBNA from May 2007 to September 2012 was performed. Data collected for patients with a history of breast cancer included patient demographics, tumor pathology, receptor analysis, imaging, and bronchoscopy or surgical results.

RESULTS

Sixty-four patients with a history of breast cancer aged from 31 to 81 years underwent EBUS-TBNA for the evaluation of mediastinal lymphadenopathy of which 16 patients had not been previously treated for their breast cancer with systemic therapy. Eighty suspicious lymph nodes were biopsied measuring 0.8 to 3.1 cm in diameter. Fifty-nine (92%) patients had diagnostic cytology for malignancy or benign lymphoid tissue. Breast malignancy was identified in 33 (52%) patients and 23 (70%) of these had sufficient samples for the evaluation of estrogen, progesterone, and human epidermal growth factor receptor 2 status. Overall 48% of the patients with receptors analyzed had discordance between the primary tumor and metastasis.

CONCLUSIONS

EBUS-TBNA is a useful tool for evaluating mediastinal lymphadenopathy in patients with a history of breast cancer and can provide information on the concordance of receptors status between the primary tumor and metastatic sites in the thorax.

Evaluation of Carcinoma of Unknown Primary on Cytologic Specimens

Carcinoma of unknown primary is defined as metastatic carcinoma without a clinically obvious primary tumor. Determining the tissue of origin in carcinoma of unknown primary is important for site-directed therapy. Immunohistochemistry is the most widely used tool for the work-up of metastases, but molecular profiling assays are also available. This review provides an overview of immunohistochemical stains in the work-up of metastatic carcinoma, with a focus on newer site-specific markers, and discusses the role of gene expression profiling assays for determining tissue of origin. The utility of cytopathology specimens in the evaluation of carcinoma of unknown primary also is highlighted.

The usefulness of various cytologic specimen preparations for PD-L1 immunostaining in non-small cell lung carcinoma

INTRODUCTION

Evaluation of programmed cell death ligand-1 (PD-L1) on formalin-fixed paraffin-embedded (FFPE) histologic specimens is required for immunotherapy with pembrolizumab in non-small cell lung carcinoma (NSCLC). A significant percent of patients may be diagnosed on cytology samples alone; however, FFPE tissue may not always be available. Here, we evaluated the feasibility of PD-L1 staining on a variety of cytologic preparations including conventional cell blocks (CB), cell-transfer cell blocks (CTCB), and direct smears.

MATERIALS AND METHODS

We identified 30 NSCLC cytology cases that had PD-L1 status evaluated on a concurrent core needle biopsy. Papanicolaou-stained smears (PS) were reviewed and a moderately cellular smear was selected per case to prepare a CTCB. CTCB, CB, and PS (when available) were stained with PD-L1 22C3 and tumor proportion scores (TPS) were compared across all preparations with the concurrent core biopsies.

RESULTS

Concordance of PD-L1 positivity in CB and PS versus core biopsy was high, 80% (12 of 15) and 94.4% (17 of 18), respectively. CTCB versus core biopsy concordance was lower in comparison, 62% (13 of 21) for PD-L1 positivity. Overall, TPS was lower in CTCB compared with CB and PS. Among the 3 preparations, CTCB and CB sections were easier to interpret as PS displayed various artifactual staining patterns.

CONCLUSIONS

In summary, our study demonstrates that CB and PS preparations are suitable surrogates for histologic FFPE tissue for determining PD-L1 status in NSCLC patients. CTCBs, on the other hand, show high discordance and are not optimal specimens. Pre-analytic factors in unconventional cytology preparations may need optimization and negative results should be interpreted with caution.

Evaluation of Estrogen and Progesterone Receptors and Her-2 Expression with Grading in the Fine-needle Aspirates of Patients with Breast Carcinoma

Background:

There has been a limited literature with regards to comparison between the pre-operative hormonal/Her-2 neu assessment by immunostaining on fine-needle aspiration (FNA) versus core needle biopsies (CNBs) and their correlation with grading of breast carcinoma.

Materials and Methods:

Two hundred fifty FNAs and 201 CNBs from 252 patients with breast carcinoma were subjected immunocytochemical/histochemical (ICC/IHC) staining along with the grading by the Robinson cytologic and modified Scarff-Bloom-Richardson scoring systems, respectively. Depending on the material adequacy, IHC was also performed on cell blocks. Sensitivity, specificity, and predictive values of ICC were calculated. The kappa statistics was performed to see the power of the study. Cytologic versus histologic gradings were compared and analysed by percentage analysis.

Results:

Sensitivity of ICC on FNAs for ER, PR, and Her-2neu was 49%, 28.8%, and 46%, respectively, while specificity was 84.5%, 90.6%, and 86.6%, respectively, with a fair agreement on kappa statistics. Her-2neu positivity on CNB versus FNA had a moderate agreement. Her-2neu staining of 3+ was seen in most of the Grade-2 tumours on FNA.

Conclusions:

Fairly reliable results on grading and hormonal/Her-2neu status are possible when ICC is performed on qualitatively superior FNA material. This is particularly useful in the management of patients in certain settings like inoperable cases.

HER2 FISH concordance in breast cancer patients with both cytology and surgical pathology specimens

INTRODUCTION

Fluorescence in Situ Hybridization (FISH) for Human Epidermal Growth Factor Receptor 2 (HER2) is traditionally performed on histologic specimens; there are no guidelines for validation of HER2 testing on cytology specimens. Our aim was to correlate HER2 FISH results on cytologic and histologic specimens.

MATERIALS AND METHODS

A retrospective search was conducted to identify breast carcinomas with HER2 FISH testing on both cytologic and histologic specimens. Results were interpreted using updated 2013 ASCO/CAP guidelines.

RESULTS

54 women with HER2 FISH results on both cytologic and histologic specimens were identified. HER2 FISH was performed on 26 formalin-fixed thrombin clot cell blocks, 6 Cellient (Hologic, Inc., Bedford, MA) cell blocks and 22 ThinPrep slides, and was negative in 43 (87%), positive in 8 (15%), and equivocal in 3 (5%) cases. Of 43 negative cytology cases, the histologic specimen was also negative in 40 (93%). Of 8 positive cytology cases, the histologic specimen was positive in 5 (63%). Overall, 48 of 54 cases (89%) had a concordant result. In patients with a discordant result, the average interval between HER2 FISH testing was 7 years. Three of 6 discordant cases showed HER2 genetic heterogeneity. Five patients received adjuvant chemotherapy, 2 received endocrine therapy, and 1 received trastuzumab.

CONCLUSIONS

FISH is reliable for determining HER2 status in cytopathology specimens. Discordant results between cytologic and surgical specimens are uncommon; possible explanations include genetic heterogeneity or inherent molecular changes associated with disease progression and therapies that occur between testing of the primary carcinoma and the metastasis.

Identification of oestrogen, progesterone receptor and human epidermal growth factor receptor 2 expression in mediastinal metastases of breast cancer obtained by endobronchial ultrasound-guided transbronchial needle aspiration

BACKGROUND

In breast cancer patients, the expression statuses of oestrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) are crucial in the choice of treatment. Receptor expression in metastatic lesions can differ from the primary tumour. The aim of our study was to analyse the utility of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) to obtain samples allowing the identification of ER, PR and HER2 expression in patients with mediastinal metastases of breast cancer.

PATIENTS AND METHODS

The clinical files of all patients with a final diagnosis of breast cancer mediastinal metastases diagnosed by EBUS-TBNA in our institution were retrospectively analysed. The ability of EBUS-TBNA to obtain samples that allowed hormone receptor and HER2 expression analysis was calculated.

RESULTS

Twenty-four patients were included. ER, PR and HER2 assessments could be performed in 22, 20 and 22 patients, respectively. In 20 of the 24 patients it was possible to investigate all three types of receptor expression. In the remaining four cases, where ER, PR or HER2 expression tests could not be performed, it was due to a lack of tissue. In cases with adequate results for EBUS-TBNA and the primary tumour agreement was greater for ER (16/19) and HER2 (12/14) than PR (8/17). Based on receptor status, there was a change in the choice of treatment for five patients.

CONCLUSION

In patients with breast cancer mediastinal metastases, ER, PR and HER2 expression can be assessed in samples obtained by EBUS-TBNA whenever a sufficient tissue sample is collected.

HER2 Testing and Clinical Decision Making in Gastroesophageal Adenocarcinoma: Guideline From the College of American Pathologists, American Society for Clinical Pathology, and the American Society of Clinical Oncology

Context ERBB2 (erb-b2 receptor tyrosine kinase 2 or HER2) is currently the only biomarker established for selection of a specific therapy for patients with advanced gastroesophageal adenocarcinoma (GEA). However, there are no comprehensive guidelines for the assessment of HER2 in patients with GEA. Objectives To establish an evidence-based guideline for HER2 testing in patients with GEA, formalize the algorithms for methods to improve the accuracy of HER2 testing while addressing which patients and tumor specimens are appropriate, and to provide guidance on clinical decision making. Design The College of American Pathologists (CAP), American Society for Clinical Pathology (ASCP), and the American Society of Clinical Oncology (ASCO) convened an Expert Panel to conduct a systematic review of the literature to develop an evidence-based guideline with recommendations for optimal HER2 testing in patients with GEA. Results The Panel is proposing 11 recommendations with strong agreement from the open comment participants. Recommendations The Panel recommends that tumor specimen(s) from all patients with advanced GEA, who are candidates for HER2-targeted therapy, should be assessed for HER2 status before the initiation of HER2-targeted therapy. Clinicians should offer combination chemotherapy and an HER2-targeted agent as initial therapy for all patients with HER2-positive advanced GEA. For pathologists, guidance is provided for morphologic selection of neoplastic tissue, testing algorithms, scoring methods, interpretation and reporting of results, and laboratory quality assurance. Conclusion This guideline provides specific recommendations for assessment of HER2 in patients with advanced GEA while addressing pertinent technical issues and clinical implications of the results.

HER2 Testing and Clinical Decision Making in Gastroesophageal Adenocarcinoma: Guideline From the College of American Pathologists, American Society for Clinical Pathology, and American Society of Clinical Oncology

CONTEXT

- ERBB2 (erb-b2 receptor tyrosine kinase 2 or HER2) is currently the only biomarker established for selection of a specific therapy for patients with advanced gastroesophageal adenocarcinoma (GEA). However, there are no comprehensive guidelines for the assessment of HER2 in patients with GEA.

OBJECTIVES

- To establish an evidence-based guideline for HER2 testing in patients with GEA, to formalize the algorithms for methods to improve the accuracy of HER2 testing while addressing which patients and tumor specimens are appropriate, and to provide guidance on clinical decision making.

DESIGN

- The College of American Pathologists, American Society for Clinical Pathology, and American Society of Clinical Oncology convened an expert panel to conduct a systematic review of the literature to develop an evidence-based guideline with recommendations for optimal HER2 testing in patients with GEA.

RESULTS

- The panel is proposing 11 recommendations with strong agreement from the open-comment participants.

RECOMMENDATIONS

- The panel recommends that tumor specimen(s) from all patients with advanced GEA, who are candidates for HER2-targeted therapy, should be assessed for HER2 status before the initiation of HER2-targeted therapy. Clinicians should offer combination chemotherapy and a HER2-targeted agent as initial therapy for all patients with HER2-positive advanced GEA. For pathologists, guidance is provided for morphologic selection of neoplastic tissue, testing algorithms, scoring methods, interpretation and reporting of results, and laboratory quality assurance.

CONCLUSIONS

- This guideline provides specific recommendations for assessment of HER2 in patients with advanced GEA while addressing pertinent technical issues and clinical implications of the results.

HER2 Testing and Clinical Decision Making in Gastroesophageal Adenocarcinoma: Guideline From the College of American Pathologists, American Society for Clinical Pathology, and American Society of Clinical Oncology

CONTEXT

ERBB2 (erb-b2 receptor tyrosine kinase 2 or HER2) is currently the only biomarker established for selection of a specific therapy for patients with advanced gastroesophageal adenocarcinoma (GEA). However, there are no comprehensive guidelines for the assessment of HER2 in patients with GEA.

OBJECTIVES

To establish an evidence-based guideline for HER2 testing in patients with GEA, to formalize the algorithms for methods to improve the accuracy of HER2 testing while addressing which patients and tumor specimens are appropriate, and to provide guidance on clinical decision making.

DESIGN

The College of American Pathologists, American Society for Clinical Pathology, and American Society of Clinical Oncology convened an expert panel to conduct a systematic review of the literature to develop an evidence-based guideline with recommendations for optimal HER2 testing in patients with GEA.

RESULTS

The panel is proposing 11 recommendations with strong agreement from the open-comment participants.

RECOMMENDATIONS

The panel recommends that tumor specimen(s) from all patients with advanced GEA, who are candidates for HER2-targeted therapy, should be assessed for HER2 status before the initiation of HER2-targeted therapy. Clinicians should offer combination chemotherapy and a HER2-targeted agent as initial therapy for all patients with HER2-positive advanced GEA. For pathologists, guidance is provided for morphologic selection of neoplastic tissue, testing algorithms, scoring methods, interpretation and reporting of results, and laboratory quality assurance.

CONCLUSIONS

This guideline provides specific recommendations for assessment of HER2 in patients with advanced GEA while addressing pertinent technical issues and clinical implications of the results.

Utilization of Cell-Transfer Technique for Molecular Testing on Hematoxylin-Eosin–Stained Sections: A Viable Option for Small Biopsies That Lack Tumor Tissues in Paraffin Block

Context.—

In some instances the standard method of doing molecular testing from formalin-fixed, paraffin-embedded block is not possible because of limited tissue. Tumor cell–enriched cell-transfer technique has been proven useful for performing immunocytochemistry and molecular testing on cytologic smears.

Objective.—

To establish the cell-transfer technique as a viable option for isolating tumor cells from hematoxylin-eosin (H&E)–stained slides.

Design.—

Molecular testing was performed by using the cell-transfer technique on 97 archived H&E-stained slides from a variety of different tumors. Results were compared to the conventional method of molecular testing.

Results.—

Polymerase chain reaction–based molecular testing via the cell-transfer technique was successfully performed on 82 of 97 samples (85%). This included 39 of 47 cases for EGFR, 10 of 11 cases for BRAF, and 33 of 39 cases for KRAS mutations. Eighty-one of 82 cell-transfer technique samples (99%) showed agreement with previous standard method results, including 4 mutations and 35 wild-type alleles for EGFR, 4 mutations and 6 wild-type alleles for BRAF, and 11 mutations and 21 wild-type alleles for KRAS. There was only 1 discrepancy: a cell-transfer technique with a false-negative >KRAS result (wild type versus G12C).

Conclusions.—

Molecular testing performed on H&E-stained sections via cell-transfer technique is useful when tissue from cell blocks and small surgical biopsy samples is exhausted and the only available material for testing is on H&E-stained slides.

Anaplastic Lymphoma Kinase Immunocytochemistry on Cell-Transferred Cytologic Smears of Lung Adenocarcinoma

BACKGROUND

Anaplastic lymphoma kinase (ALK) immunohistochemical staining on formalin-fixed paraffin-embedded tissue or cell blocks (CB) has been reported as an effective alternative to fluorescence hybridization in situ (FISH) for the detection of ALK gene rearrangement. However, CB frequently lack adequate cellularity even when the direct smears are cellular. This study aims to assess the utility of ALK immunocytochemical (ICC) staining on direct smears using the cell transfer (CT) technique for the detection of ALK rearrangement.

METHODS

Fine-needle aspiration (FNA) cases of lung adenocarcinoma in which the ALK status had been determined by FISH on CB or a concurrent biopsy were identified. ICC staining for ALK was performed on alcohol-fixed Papanicolaou-stained direct smears using the CT technique. ALK immunoreactivity was evaluated using a modified semiquantitative scale. Results were compared with those of FISH.

RESULTS

A total of 47 FNA specimens were included. Five of 7 FISH-positive cases showed positive ALK ICC staining (71.4%), and 39 of 40 FISH-negative cases were negative on ALK ICC staining (97.5%). The overall correlation between ALK ICC and FISH was 93.6%.

CONCLUSION

ICC performed on FNA smears using the CT technique is an alternative method for the assessment of ALK rearrangement, especially when CB lack adequate cellularity.

Immunocytochemical results for HER2 and Ki67 in breast cancer touch-smear cell specimens are reliable

BACKGROUND

Re-evaluation of the subtype of recurrent breast cancer is necessary for deciding the treatment approach, but it is often not performed due to the difficulty of obtaining tissue specimens from a recurrent lesion, etc. However, when a recurrent lesion is close to the body surface, fine-needle aspiration cells (FNA cells) can be easily obtained, and immunocytochemical (ICC) analysis of hormone receptors expression in FNA cells is said to be highly reliable. However, there is no consensus regarding ICC analysis of human epidermal growth factor receptor type 2 (HER2) expression and the Ki67 index using FNA cells.

METHODS

Touch-smear cells (TSC) were prepared from resected specimens from 36 patients with primary invasive ductal carcinoma of the breast. The TSC were fixed in 95 % ethanol and subjected to ICC analysis for HER2 using HercepTest™ (Dako) and Ki67 using MIB-1™ (Dako). HER2 expression and the Ki67 index for the TSC were compared with the results of immunohistochemical analysis of histological section (HS). Statistical analyses used the kappa test and Pearson's correlation coefficients.

RESULTS

HER2 and Ki67 were analyzed in TSC from 36 and 28 patients, respectively. The HER2 expression scores in the TSC and HS groups showed good agreement (kappa value =0.640) and significant correlation (correlation coefficient =0.860, p < 0.001). The Ki67 indexes in the TSC and HS groups also showed significant correlation (correlation coefficient =0.861, p < 0.001).

CONCLUSIONS

The reliability of ICC analysis of HER2 expression and the Ki67 index using TSC were recognized.

Principles of analytic validation of immunohistochemical assays: Guideline from the College of American Pathologists Pathology and Laboratory Quality Center

CONTEXT

Laboratories must validate all assays before they can be used to test patient specimens, but currently there are no evidence-based guidelines regarding validation of immunohistochemical assays.

OBJECTIVE

To develop recommendations for initial analytic validation and revalidation of immunohistochemical assays.

DESIGN

The College of American Pathologists Pathology and Laboratory Quality Center convened a panel of pathologists and histotechnologists with expertise in immunohistochemistry to develop validation recommendations. A systematic evidence review was conducted to address key questions. Electronic searches identified 1463 publications, of which 126 met inclusion criteria and were extracted. Individual publications were graded for quality, and the key question findings for strength of evidence. Recommendations were derived from strength of evidence, open comment feedback, and expert panel consensus.

RESULTS

Fourteen guideline statements were established to help pathology laboratories comply with validation and revalidation requirements for immunohistochemical assays.

CONCLUSIONS

Laboratories must document successful analytic validation of all immunohistochemical tests before applying to patient specimens. The parameters for cases included in validation sets, including number, expression levels, fixative and processing methods, should take into account intended use and should be sufficient to ensure that the test accurately measures the analyte of interest in specimens tested in that laboratory. Recommendations are also provided for confirming assay performance when there are changes in test methods, reagents, or equipment.

The usefulness of the cell transfer technique for immunocytochemistry of fine-needle aspirates

BACKGROUND

The use of immunocytochemistry as an important ancillary technique for the workup of fine-needle aspiration (FNA) specimens is an important component in the daily practice of cytopathology. Although cell block preparations are commonly used, immunocytochemistry cannot be completed if the cell blocks are hypocellular. As an alternative approach when conventional cell blocks fail, immunocytochemistry can be performed on cell-transferred direct smears. Multiple immunostains can be applied to a single direct smear using the cell transfer technique (CTT).

METHODS

A retrospective review of all FNA cases performed at the study institution over a 3-year period was conducted. All cases in which CTT was used for immunocytochemistry were identified. The contribution of CTT to the final diagnosis in these cases was assessed.

RESULTS

CTT was used in 152 of the 11,259 FNAs performed. A total of 431 immunocytochemistry stains, including 46 different antibodies, were performed using CTT. In 118 of 150 cases, the immunocytochemistry results contributed significantly to the final diagnosis. It provided no added value in the remaining 32 cases and failed in 2 cases.

CONCLUSIONS

CTT is a very useful tool for the workup and diagnosis of FNA specimens when conventional cell blocks lack adequate cellularity. Although CTT was used in only 1.4% of FNA cases in the current study, it contributed to the final diagnosis in 79% of the cases in which it was used. For these patients, CTT reduced the need for repeat FNAs, thereby reducing potential patient morbidity and health care costs.

Utilization of cell-transferred cytologic smears in detection of EGFR and KRAS mutation on adenocarcinoma of lung

Cell-transfer technique has been proven useful for performing immunocytochemistry on fine-needle aspiration smears. However, its utility for EGFR and KRAS molecular testing has not been validated. Molecular testing was performed using the cell-transfer technique on both Papanicolaou-stained ethanol-fixed and Hema 3-stained air-dried smears from 32 fine-needle aspiration samples that had diagnoses of adenocarcinoma of the lung, and then was compared to the results of the corresponding formalin-fixed paraffin-embedded tissues. The molecular testing was successfully performed on 32 of 32 ethanol-fixed and 31 of 32 air-dried samples. The molecular results on ethanol-fixed and air-dried smears showed 100% agreement. There is 100% (32/32) agreement for the EGFR and 97% (31/32) agreement for the KRAS between the cell-transfer technique and formalin-fixed paraffin-embedded tissues. One discrepant case was due to low percentage of tumor cells on the smears. Cell-transfer technique is a reliable alternative method for EGFR and KRAS testing if the cell blocks lack adequate cellularity.

Is liquid-based cytology the magic bullet for performing molecular techniques?

OBJECTIVE

The role of pathology has evolved from the first microscopic definitions of diseases by Virchow to the new concept of molecular cytopathology. The management of diseases is now a multidisciplinary approach with the translation of morphological, imagery and molecular findings to therapeutic protocols. Obtaining the most reliable diagnostic material is the essential part of the medical management of patients.

STUDY DESIGN

Here, we try to gain a concise insight into the available data regarding the role of cytology in the application of molecular techniques, focusing on cancer cytopathology.

RESULTS

Obtaining cytological material is now feasible by different methods, and in some cases it is the only possible approach to a lesion which is not easily accessible for tissue sampling. The methods of obtaining cytological material have evolved in recent years in parallel with rapid advances in high-throughput molecular techniques, opening new windows for the diagnosis and management of diseases.

CONCLUSIONS

Different kinds of cytological material are reliable for the application of molecular techniques. Cytological material obtained in a liquid base has advantages such as the better preservation of cytomorphological features and the use of the remaining liquid for nucleic acid extraction even after long storage and the application of molecular methods.

Fine-needle aspiration cytology can play a role in neoadjuvant chemotherapy in operable breast cancer

Despite the fact that CNB has been progressively replaced by FNAC in the investigation of nonpalpable lesions or microcalcifications without a clinical or radiological mass lesion, FNAC has yet a role in palpable lesions provided it is associated with the triple diagnosis and experienced cytologist. In these conditions, FNAC is a safe, effective, economical, and accurate technique for breast cancer evaluation. Numerous literature reviews and meta-analyses illustrated the advantages and disadvantages of both methods CNB and FNAC. The difference does not seem significant when noninformative and unsatisfactory FNAC was excluded. Recently, cytological methods using liquid-based cytology (LBC) technology improve immunocytological and molecular tests with the same efficiency as classical immunohistochemistry. The indications of FNAC were, for palpable lesions, relative contraindication of CNB (elderly or frailty), staging of multiple nodules in conjunction or not with CNB, staging of lymph node status, newly appearing lesion in patient under neoadjuvant treatment, decreasing of anxiety with a rapid diagnosis, evaluation of biomarkers and new biomarkers, and chronological evaluation of biomarker following the neoadjuvant therapy response.

Immunocytochemistry performed on the cell-transferred direct smears of the fine-needle aspirates: a comparison study with the corresponding formalin-fixed paraffin-embedded tissue

Immunocytochemistry (ICC) performed on the cell-transferred cytologic smears (CTCS) of fine-needle aspiration (FNA) is useful when the cell blocks lack adequate material. The comparison of the ICC results from the CTCS of FNA with the corresponding formalin-fixed paraffin-embedded tissue (FFPE) has not been reported previously. We applied 12 commonly used ICC antibodies on 160 pieces of ethanol-fixed, cell-transferred Papanicolaou-stained smears obtained from 42 FNA specimens and compared the staining results with the corresponding FFPE on which the same panel of immunostains was performed. Of the 160 pieces of transferred materials, only 3 (1.9%) were lost during specimen processing. In total, 153 of 157 (97.5%) showed staining results that agreed with the corresponding FFPE, including 78 of 81 positive staining and 75 of 76 negative staining cases. ICC performed on the cell-transferred FNA smears is reliable and shows staining results highly comparable with the corresponding FFPE tissue.