1 Human Epidermal Growth Factor Receptor 2 (HER2) Testing - Validation, Application and Correlation Her2 is encoded by the C-erbB2 gene and is one of four oncoproteins belonging to the Human Epidermal Growth Factor Receptor (HER1-4) family of tyrosine kinases and is over-expressed in approximately 20% of invasive breast cancer cases. Over-expression of these pathways leads to excessive activation and may contribute to more aggressive growth associated with these tumors. Her2 over-expression is associated with poor prognosis and resistance to certain chemotherapeutic agents. Milestones in Her 2 Testing 1 FDA CLASSFIES IHC ASCO/CAP, INTRO. GUIDELINES FOR HER2 DISTRIBTION OF CAP TESTING QUESTIONAIRE PUBLICATION OF QUESTIONAIRE RESULTS PUBLICATION OF HER 2 GUIDELINES ADDITION OF ANP.22750, REVISED ASCO/CAP HER2 GUIDELINES
2 Optimization-Validation Method Ventana Pathway Controls ( cell line & tissue sections) The performance of the PATHWAY HER2 (4B5) Rabbit monoclonal Primary Antibody has been evaluated by Ventana, through specificity, reproducibility and method comparison studies PATHWAY HER2 (4B5) specificity was determined by a study that showed no specific membrane staining for most normal tissues. Positive and negative agreement rates with two-sided score 95% confidence intervals were calculated for the six possible pair-wise comparisons Deparaffinization (selected) 20 min. CC1 30 min CC1 52 min CC1 64 min CC1 Primary AB- 12 min incubation Hematoxylin II counterstain 4 min Bluing 4 minutes Positive control for PATHWAY HER2 (4B5) is a known weak HER-2/neu positive invasive breast carcinoma (for example ductal or lobular). Lot controlled cell line at all expression levels, lot controlled 2 Same slide used for the positive tissue control (ductal or lobular invasive breast carcinoma) is the negative tissue control. The non-staining components (surrounding stroma, lymphoid cells and blood vessels) should demonstrate absence of specific staining, or normal breast Intra-run reproducibility of staining on the NexES, BenchMark, and BenchMark XT staining instrument platforms was determined by staining three slides each of five breast cancer tissues with a score of 0, 1+, 2+, and 3+ HER-2 expression Negative reagent control is used in place of the primary antibody to evaluate nonspecific staining. The slide should be stained with CONFIRM Negative Control Rabbit Ig. The incubation period for the negative reagent control should equal the primary antibody incubation period
3 Optimization-Validation Method Leica Oracle Controls ( cell line & tissue sections) The performance of the Oracle Primary Antibody ( CB11) has been evaluated by Leica, through specificity, reproducibility and method comparison studies. Staining patterns were verified by Leica, using a large panel of normal tissues. The Oracle system was developed to provide an alternative to the investigational clinical trial assay (CTA) used in the Herceptin clinical studies. Oracle was compared to Hercep test using 431 breast tumor specimens, with 92.34% concordance. Oracle HER2 (CB11) specificity was determined by a study that showed no specific membrane staining for most normal tissues. The slide layout provided in the IFU should be used to get the maximum tests from each kit. Between laboratories reproducibility was evaluated by Leica at three sites. Inter-observer reproducibility was evaluated using 40 randomly selected invasive breast cancer cases, agreement 87.5%. Clone CB11 ( mouse monoclonal) targets the Her2 oncoprotein located on the cell membrane using the primary antibody which is visualized via a compact polymer detection system. The system has a preloaded protocol, with HIER 25 min with ER1(97), and IHC staining protocol H. A new bond cover tile should be used with each Her2 stained slide. 60 tests ( 150 slides) 60 slides with Her2 AB 60 slides with negative reagent 15 Her2 control slides with AB 15 positive in house tissue controls Negative control is a ready to use mouse IgG at equivalent concentration to the primary AB. Lot controlled cell line at all expression levels, lot controlled. Each lot contains 4 NBF fixed human breast cancer cell lines, which express all staining intensities. 3 In house positive tissue controls are used and indicative of correctly prepared tissues, ideal is a weak positive. In house negative controls verify the specificity of the primary antibody. Normal breast ducts unassociated with tumor act as an internal reference. Use of a MTB block is highly recommended. Slide arrangement 1-Her2 control slide 2-iIn house positive control 3-In house negative control 4-Patient tissue-her2 negative control 5-Patient tissue-her2 primary antibody
4 Validation Definitions In Vitro Diagnostic Product (IVD)FDA Definitions reagents intended for use in diagnosis of disease (in) specimens taken from the human body. For immunohistochemistry: Class I: provide the pathologist with adjunctive diagnostic information minimal potential for harm to the user. Class II: provide prognostic or predictive data mandatory performance standards Analyte Specific Reagents (ASRs) Non-IVD diagnostic reagent Not bundled with other materials in a kit Not subject to FDA preclearance or special controls Product literature makes no claims regarding use or performance 4 Class II IHC Tests-(results used by non-pathologists) Stand alone diagnostic, Predictive or prognostic, Widely accepted valid scientific claims E.g. hormone receptors in breast cancer FDA vs. Non-FDA Approved Systems FDA approved: May use data from manufacturer or from published reports, but MUST verify Sensitivity, Specificity /Accuracy, Precision, Reportable Range Non-FDA approved: Must establish accuracy, precision, analytic sensitivity, interferences & reportable range Includes modified FDA-approved systems!
5 Table 1 Summary of ASCO/CAP Selected Guidelines 2007 Recommendation 2013 Recommendation ISH Interpretation Count at least 20 cells, pathologist must confirm counting involves invasive component Bright field ISH, pathologist scans entire slides prior to counting 20 cells. Comparison needed between normal breast and tumor cells to manage difficult to interpret areas. Acceptable ISH and IHC tests Should preferentially use FDA approved IHC, ISH or FISH test. IHC rejection criteria Test rejected or repeated with FISH if; controls are not as expected, artifacts involve most of the sample, sample has strong membrane staining in normal breast ducts. same 5 IHC interpretation criteria + Her2 results requires homogenous, dark, circumferential pattern in >30% of invasive tumor ( chicken wire pattern) Should interpret IHC using a threshold or more than 10% of tumor cells that show homogeneous, dark circumferential pattern to be 3+ positive. Reporting requirements Report must include guideline detailed elements Same, and changes to reporting requirements and algorithms. Source: Guideline Summary of Her2 Recommendations, American Society of Clinical Oncologists and College of American Pathologists, 2013.
6 Descriptions of Her2 Scoring Criteria: IHC result of 3+ cell surface protein expression (uniform intense membrane staining of > 30% of invasive tumor cells, or FISH result of amplified Her2 gene copy number (average of > 6 copies/nucleus or Her2/CEP ratio of > 2.2). Equivocal Her2- IHC scores of 2+ (complete membrane staining that is either non-uniform or weak intensity in at least 10% of cells), or FISH scores with Her2/CEP ratios of or average gene copy numbers between 4.o-6.o. Note that patients with Her2/CEP ratios of were formerly considered Her2+ and were eligible for Herceptin ( 3% of samples), data does not support excluding them at this time. Negative Her2- either an IHC result of 0 or 1+ for cellular protein membrane expression ( no staining or weak, incomplete membrane staining in any proportion of tumor cells), or FISH result of Her2/CEP ratio less than 1.8 or average of fewer than 4 copies of Her2 gene. Equivocal results from a single test require additional action. Equivocal IHC must be confirmed by FISH. Equivocal FISH are confirmed by enumerating additional cells or repeat assay. 6 CISH amplification is defined as greater than 10 discrete copies per nucleus or as large gene copy clusters in >50% of nuclei. Unaltered gene copy is 1-5 copies per nucleus (Tanner). SOURCE - SUMMARY of 2007 & 2013 RECOMMENDATIONS
7 IHC result of 3+ cell surface protein expression (uniform intense membrane staining of > 30% of invasive tumor cells, or FISH result of amplified Her2 gene copy number ( average of > 6 copies/nucleus or Her2/CEP ratio of > 2.2). Equivocal Her2- IHC scores of 2+ (complete membrane staining that is either non-uniform or weak intensity in at least 10% of cells), or FISH scores with Her2/CEP ratios of or average gene copy numbers between 4.o-6.o. Note that patients with Her2/CEP ratios of were formerly considered Her2+ and were eligible for Herceptin ( 3% of samples), data does not support excluding them at this time. Negative Her2- either an IHC result of 0 or 1+ for cellular protein membrane expression ( no staining or weak, incomplete membrane staining in any proportion of tumor cells), or FISH result of Her2/CEP ratio less than 1.8 or average of fewer than 4 copies of Her2 gene. Equivocal results from a single test require additional action. Equivocal IHC must be confirmed by FISH. Equivocal FISH are confirmed by enumerating additional cells or repeat assay. 7 CISH amplification is defined as greater than 10 discrete copies per nucleus or as large gene copy clusters in >50% of nuclei. Unaltered gene copy is 1-5 copies per nucleus ( Tanner). SEE HANDOUT-SUMMARY of 2007 & 2013 RECOMMENDATIONS
8 EXAMPLE-DRAFT of VALIDATION SUMMARY: HER2 Antibody Optimization-Validation Summary Antibody: Her 2 Titer/Concentration: pre-diluted dispenser Species: Rabbit Monoclonal Catalog #: Clone: 4B5 Localization: membrane Status & Intended use: This antibody is intended for in vitro diagnostic use. PATHWAY anti-her-2/neu is a rabbit monoclonal antibody (clone 4B5) directed against the internal domain of the c-erbb-2 oncoprotein (HER2). c-erbb-2 oncoprotein was cloned and characterized by Akiyama, et al in It is an approximately 185 kd transmembrane glycoprotein which is structurally similar to epidermal growth factor receptor (EGFR). The protein is associated with tyrosine kinase activity similar to that of several growth factor receptors, and to that of the transforming proteins of the src family. The coding sequence is consistent with an extracellular binding domain and an intracellular kinase domain. This suggests that HER2 may be involved in signal transduction and stimulation of mitogenic activity. Clone 4B5 has been shown to react with a 185 kd protein from SK-BR-3 cell lysates via Western blotting. SK-BR-3 is a breast carcinoma cell line, which has a 128-fold over expression of HER2 mrna. The size of the band identified correlates well with that reported by Akiyama et al for HER2 protein (185 kd). Immunohistochemistry has been used to detect specific antigens in cells or tissue since The use of enzymes and peroxidase as markers for immunohistochemistry was reported by Nakane and Pierce in The HER2 protein is expressed at a level detectable by immunohistochemistry in up to 20 percent of adenocarcinomas from various sites. Between 15 and 30 percent of invasive ductal cancers are positive for HER2. Almost all cases of Paget s disease of breast, and up to 90 percent of cases of ductal carcinoma in situ of comedo type are positive. The immunohistochemical detection of HER2 protein overexpression is also used as an aid in determination of patients for whom Herceptin therapy is indicated. Staining results in normal tissues, neoplastic tissues, and 322 cases of breast carcinoma with PATHWAY HER2 (4B5) were evaluated by Ventana. 8 Purpose: Immunohistochemical staining is used to determine the presence or absence of the targeted antigen in formalin-fixed, paraffin embedded tissue. The Ventana Medical Systems, Inc.'s (Ventana) PATHWAY anti-her-2/neu (4B5) Rabbit Monoclonal Primary Antibody (PATHWAY HER2 (4B5)) is a rabbit monoclonal antibody intended for laboratory use for the semi-quantitative detection of HER2 antigen in sections of formalinfixed, paraffin-embedded normal and neoplastic tissue on a VENTANA automated immunohistochemistry slide staining device. It is indicated as an aid in the assessment of breast cancer patients for whom Herceptin treatment is considered.
9 Clinical Methods: PATHWAY HER2 (4B5) is a rabbit monoclonal antibody, which binds to HER2 in paraffin-embedded tissue sections. The specific antibody can be localized by a conjugated secondary antibody formulation that recognizes rabbit immunoglobulins followed by the addition of a secondary antibody-hrp conjugate (ultraview Universal DAB Detection Kit). The specific antibody-enzyme complex is then visualized with a precipitating enzyme reaction product. Each step is incubated for a precise time and temperature. At the end of each incubation step, the VENTANA automated slide stainer washes the sections to stop the reaction and to remove unbound material that would hinder the desired reaction in subsequent steps. It also applies Liquid Coverslip, which minimizes evaporation of the aqueous reagents from the specimen slide. Clinical cases should be evaluated within the context of the performance of appropriate controls. A positive tissue control fixed and processed in the same manner as the patient specimen (for example, a weakly positive breast carcinoma) is used in addition to staining with PATHWAY HER2 (4B5), along with a slide stained with CONFIRM Negative Control Rabbit Ig. For the test to be considered valid, the positive control tissue should exhibit membrane staining of the tumor cells. These components should be negative when stained with CONFIRM Negative Control Rabbit Ig. In addition, it is recommended that a negative tissue control slide (for example, a HER-2/neu negative breast carcinoma) be included for every batch of samples processed and run on the VENTANA automated slide stainer. This negative tissue control should be stained with PATHWAY HER2 (4B5) to ensure that the antigen enhancement and other pretreatment procedures did not create false positive staining. Required Reagents & Materials Catalog # : PATHWAY anti-her-2/neu (4B5) Primary Antibody contains sufficient reagent for 50 tests. One 5 ml dispenser PATHWAY anti-her-2/neu (4B5) Primary Antibody contains approximately 30 μg of a rabbit monoclonal antibody directed against human c-erbb-2 antigen. The antibody is diluted in 0.05 M Tris buffered saline, 0.01 M EDTA, 0.05% Brij-35 with 0.3 % carrier protein and 0.05 % sodium azide, a preservative. There is trace fetal calf serum, approximately 0.25 %, present from the stock solution. Total protein concentration of the reagent is approximately 16 mg/ml. Specific antibody concentration is approximately 6 μg/ml. PATHWAY anti-her-2/neu (4B5) Primary Antibody is a rabbit IgG diluted from tissue culture supernatants. There is no known irrelevant antibody reactivity observed in this product. Reconstitution, Mixing, Dilution, and Titration: This antibody is optimized for use on a VENTANA automated slide stainer in combination with VENTANA iview DAB Detection Kit and compatible with ultraview Universal DAB Detection Kit. No reconstitution, mixing, dilution, or titration is required. The reagent is stored at 4-8 degrees Celsius when not in use. CONFIRM Negative Control Rabbit Ig (Cat. No ) (negative reagent control). The reagent is stored at 4-8 degrees Celsius when not in use. Microscope slides, such as Superfrost Plus Positive and negative tissue controls (invasive breast carcinoma and normal breast tissue) Bar code labels (appropriate for negative reagent control and primary antibody being tested) Xylene (histological grade) Ethanol or reagent alcohol (histological grade) 9
10 100% solution: undiluted ethanol or reagent alcohol, 95% solution: mix 95 parts ethanol or reagent alcohol with 5 parts of deionized water, 80% solution: mix 80 parts ethanol or reagent alcohol with 20 parts deionized water Deionized or distilled water Clinical Utility: Breast cancer is the most common carcinoma occurring in women, and the second leading cause of cancer related death. In North America, a woman s chance of contracting breast cancer is one in eight. Early detection and appropriate treatment therapies can significantly affect overall survival. Small tissue samples may be easily used in routine immunohistochemistry (IHC), making this technique, in combination with antibodies that detect antigens important for carcinoma interpretation, an effective tool for the pathologist in their diagnosis and prognosis of disease. One important marker in breast cancer today is c-erbb-2 oncoprotein (HER2). HER2 is an intracellular membrane protein detected in the cellular membrane. It is closely related to EGFR and, like EGFR, has tyrosine kinase activity. Gene amplification and the corresponding overexpression of c-erbb-2 has been found in a variety of tumors, including breast carcinomas. The therapeutic drug Herceptin has been shown to benefit some breast carcinoma patients by arresting, and in some cases reversing the growth of their cancer. The drug is a humanized monoclonal antibody that binds to HER2 protein on cancer cells. Thus only patients with HER-2/neu positive breast carcinomas should benefit from treatment with Herceptin. In vitro diagnostics for the determination of HER2 status in breast carcinomas are important to aid the clinician in determination of therapy with Herceptin. Interpretation of the results of any detection system for HER2 must take into consideration the fact that HER2 is expressed in both breast cancer tumors and healthy tissue, albeit at differing levels and with different patterns of expression. Histological tissue preparations have the advantage of intact tissue morphology to aid in the interpretation of the HER2 positivity of the sample. All histological tests should be interpreted by a specialist in breast cancer morphology, and/or pathology, and the results should be complemented by morphological studies and proper controls and used in conjunction with other clinical and laboratory data. 10 Specimen Type: The Her2 staining protocol has been optimized by Ventana on site by a technical staining specialist, and the in house performance characteristics have been verified and validated for use on non-decalcified, formalin-fixed, paraffin embedded tissue sections prepared in house, under current testing conditions, with tissue section prepared by following standard histologic procedures as described in the routine histology procedure manual. Limits of Detection: The limits of detection have been determined by multiple pre analytic and analytic factors, including the concentration of the antigen in the tissue being examined. The limit of detection, sensitivity and specificity is evaluated by the Pathologist by examination of a panel of stained tissue sections known to express or lack the target antigen.
11 Parameters of Performance & Quality Control Procedures, using Cell Line System Controls & %NBF fixed Tissues Ventana provided, separate lot controlled slides consisting of four formalin-fixed cell line controls embedded in paraffin, sectioned and placed on a single charged slide (catalog # ). PATHWAY HER-2 4 in 1 Control Slides are used for a preliminary validation of the processing method used for staining slides with PATHWAY HER2 (4B5), and for performance controls across staining runs. These four cell line controls are characterized by in situ hybridization for gene copy number. When processed and stained appropriately, the cell lines should stain as described in the PATHWAY Her-2 4 in 1 Control Slide package insert. If the indicated staining is not evident in the appropriate cores, especially the 1+ and 2+ controls, the staining of the tissues should be repeated. Table 1. Characteristics of PATHWAY HER-2 4 in 1 Control Slides HER2 Cell Line HER2/Chr17 Ratio* IHC Score 0 MDA-MB T47D MDA-MB BT Tissue Controls for Each Staining Run: When sufficient material is available, multiple tissue controls with known positive at all expression levels and tissues with known negative expression are utilized for optimal run to run and lot to lot quality control. When sufficient material is not available, single tissue sections reflecting positive and negative staining patterns are run together or in parallel as described within quality control procedures for tissue & reagent performance control and control for lot to lot verification. 11 Positive Tissue Control A positive control tissue fixed and processed in the same manner as the patient specimens must be run for each set of test conditions and with every PATHWAY HER / US Rev F staining procedure performed. An example of a positive control for PATHWAY HER2 (4B5) is a known weak HER-2/neu positive invasive breast carcinoma (for example ductal or lobular). The positive staining tissue components (cytoplasmic membrane of neoplastic cells) are used to confirm that the antibody was applied and the instrument functioned properly. A known weak HER-2/neu positive invasive breast carcinoma tissue may contain both positive and negative staining cells or tissue components and may serve as both the positive and negative control tissue. Known positive tissue controls should be utilized only for monitoring the correct performance of processed tissues and test reagents, and not as an aid in determining a specific diagnosis of patient samples.
12 Negative Tissue Control The same slide used for the positive tissue control (ductal or lobular invasive breast carcinoma) may be used as the negative tissue control. The non-staining components (surrounding stroma, lymphoid cells and blood vessels) should demonstrate absence of specific staining and provide an indication of specific background staining with the primary antibody. Alternatively, normal breast tissue is an adequate negative control tissue. Use a tissue known to be fixed, processed and embedded in a manner identical to the patient sample(s) with each staining run to verify the specificity of PATHWAY HER2 (4B5) for demonstration of HER-2/neu, and to provide an indication of specific background staining (false positive staining). Negative Reagent Control A negative reagent control must be run for every specimen to aid in the interpretation of results. A negative reagent control is used in place of the primary antibody to evaluate nonspecific staining. The slide should be stained with CONFIRM Negative Control Rabbit Ig. The incubation period for the negative reagent control should equal the primary antibody incubation period. A negative reagent control is used in place of the primary antibody to evaluate nonspecific staining. The slide should be stained with CONFIRM Negative Control Rabbit Ig. The incubation period for the negative reagent control should equal the primary antibody incubation period. Records of assessment of individual staining results and pathologist interpretation are tabulated and retained with the validation staining run sheets and validation records. Single control tissue sections are identified for use in lot to lot assessments of new antibody lots of the same vendor and clone within immunohistochemistry quality control records. A minimum of one known positive and one known negative control is stained parallel to the previous lot before use of the new lot in patient testing. 12 General Limitations & Interferences Immunohistochemistry is a multi-step process that requires specialized training in the selection and use of reagents, protocol variables, tissue selection, fixation and processing requirements. Staining results achieved are highly dependent of the handling and processing of tissue prior to immunohistochemistry staining. Improper fixation, freezing, thawing, washing, drying, heating, sectioning or contamination from other tissue or fluids is likely to produce artifacts, aberrant staining, or false negative results. The clinical interpretation of immunohistochemical staining is performed only by highly trained and experienced pathologists who evaluate these results in the context of the patient s tissue morphology, clinical history, appropriate controls and other diagnostic information.
13 Specific Limitations 1. Immunohistochemistry is a multiple step diagnostic process that requires specialized training in the selection of the appropriate reagents, tissue selections, fixation, processing, preparation of the immunohistochemistry slide, and interpretation of the staining results. 2. Tissue staining is dependent on the handling and processing of the tissue prior to staining. Improper fixation, freezing, thawing, washing, drying, heating, sectioning, or contamination with other tissues or fluids may produce artifacts, antibody trapping, or false negative results. Inconsistent results may result from variations in fixation and embedding methods, or from inherent irregularities within the tissue. 3. Excessive or incomplete counterstaining may compromise proper interpretation of results. 4. The clinical interpretation of any positive staining, or its absence, must be evaluated within the context of clinical history, morphology and other histopathological criteria. The clinical interpretation of any staining, or its absence, must be complemented by morphological studies and proper controls as well as other diagnostic tests. It is the responsibility of a qualified pathologist to be familiar with the antibodies, reagents and methods used to interpret the stained preparation. Staining must be performed in a certified licensed laboratory under the supervision of a pathologist who is responsible for reviewing the stained slides and assuring the adequacy of positive and negative controls Ventana provides antibodies and reagents at optimal dilution for use when the provided instructions are followed. Any deviation from recommended test procedures may invalidate expected results. Appropriate controls must be employed and documented. Users who deviate from recommended test procedures must accept responsibility for interpretation of patient results. 6. This product is not intended for use in flow cytometry, performance characteristics have not been determined. 7. Reagents may demonstrate unexpected reactions in previously untested tissues. The possibility of unexpected reactions even in tested tissue groups cannot be completely eliminated because of biological variability of antigen expression in neoplasms, or other pathological tissues.
14 8. Tissues from persons infected with hepatitis B virus and containing hepatitis B surface antigen (HBsAg) may exhibit nonspecific staining with horseradish peroxidase. 9. False positive results may be seen because of non-immunological binding of proteins or substrate reaction products. They may also be caused by pseudoperoxidase activity (erythrocytes), endogenous peroxidase activity (cytochrome C), or endogenous biotin (example: liver, brain, breast, kidney) depending on the type of immunostain used. 10. As with any immunohistochemistry test, a negative result means that the antigen was not detected, not that the antigen was absent in the cells or tissue assayed. Specific Limitations of the Pathway System The antibody has been optimized as indicated for VENTANA platforms and detection chemistries. Because of variation in tissue fixation and processing, it may be necessary to increase or decrease the primary antibody incubation time on individual specimens. The antibody, in combination with VENTANA detection kits and accessories, detects antigen that survives routine formalin fixation, tissue processing and sectioning. Immunohistochemical testing has been validated for use with 10% neutral buffered formalin-fixed tissues. Cold ischemic and fixation times are recorded for each breast tissue sample on which Her2 testing is performed and recorded within the final pathology report. Bone marrow was not tested for specificity. 14 Interpretation of results The VENTANA automated immunostaining procedure causes a brown colored (DAB) reaction product to precipitate at the antigen sites localized by PATHWAY HER2 (4B5). A qualified pathologist experienced in immunohistochemical procedures must evaluate controls and qualify the stained product before interpreting results. Scoring Conventions for the Interpretation of PATHWAY HER2 (4B5) Breast carcinomas that are considered positive for HER-2 protein overexpression must meet threshold criteria for intensity of staining (2+ or greater on a scale of 0 to 3+) and percent positive tumor cells (greater than 10%). Staining must also localize to the cellular membrane. Cytoplasmic staining may still be present, but this staining is not included in the determination of positivity. Three fields within the well
15 preserved and well stained region of the tissue should be examined for intensity of staining and determination of completeness of the cytoplasmic membrane stain. Staining that completely encircles the cytoplasmic membrane should be scored as an intensity of 2+ or 3+. Partial staining of the membrane should be scored as a 1+. It may be necessary to examine borderline cases at 400X or higher magnification to discriminate between intensities of 1+ and 2+. In contrast to cases scored as an intensity of 3+, the staining scored as 2+ has a crisper and more clearly delineated ring, while cases scored as 3+ exhibits a very thick outline. Refer to VENTANA Interpretation Guide for PATHWAY HER- 2/neu (4B5) for a more detailed description with photographs of staining with PATHWAY HER2 (4B5). Table 2. Criteria for Intensity and Pattern of Cell Membrane Staining with PATHWAY HER2 (4B5) Staining Pattern Score (Report to Treating Physician) HER2 Staining Assessment No membrane staining is observed Faint, partial staining of the membrane in any proportion of the cancer cells Weak complete staining of the membrane, greater than 10% of cancer cells Intense complete staining of the membrane, greater than 10% of cancer cells 0 Negative 1+ Negative 2+ Weakly Positive 3+ Positive 15 Ventana Published Concordance The performance of the PATHWAY HER2 (4B5) Primary Antibody has been evaluated by Ventana, through specificity, reproducibility and method comparison studies. Specificity: PATHWAY HER2 (4B5) specificity was determined by a study that showed no specific membrane staining for most normal tissues. Staining results were as follows: adrenal (0/3), breast (0/3), cerebellum (0/3), cerebrum (0/3), cervix (0/3), colon (0/3), esophagus (1/3), heart (0/2), kidney (0/3), liver (0/3), lung (0/3), mesothelial cells (0/3), ovary (0/3), pancreas (0/3), parathyroid (1/3, focal membrane staining),
16 peripheral nerve (1/3), pituitary (0/2), prostate (1/3), salivary gland (0/3), skeletal muscle (0/3), skin (0/3), small intestine (0/3), spleen (0/3), stomach (0/3), testis (0/3), thymus (0/2), thyroid (0/3), tonsil (2/3 focal staining of surface epithelial cells), and uterus (0/3). PATHWAY HER2 (4B5) specificity was also determined by a study that showed no specific membrane staining in most neoplastic tissues. Staining results were as follows: breast cancer (1/4), carcinoid (0/2), colon cancer (1/3), hepatocellular cancer (0/5), leiomyoma (0/2), lung cancer (0/2), lymphoma (0/3), melanoma (0/2), ovarian cancer (1/2), pancreatic cancer (0/3), prostate cancer (0/3), renal cell cancer (0/5), sarcoma (0/2), stomach cancer (0/3), thyroid cancer (0/3), and undifferentiated cancer (0/1). Positive staining in tonsilar epithelieum, esophageal epithelium, prostate, peripheral nerve, parathyroid, breast cancer, colon, and ovarian cancer are consistent with published literature regarding expression of HER- 2/neu. Sensitivity: Sensitivity is dependent upon the preservation of the antigen. Any improper tissue handling during fixation, sectioning, embedding or storage which alters antigenicity weakens HER-2/neu protein detection by PATHWAY HER2 (4B5) and may generate false negative results. Intra-run reproducibility of staining on the NexES, BenchMark, and BenchMark XT staining instrument platforms was determined by staining three slides each of five breast cancer tissues with a score of 0, 1+, 2+, and 3+ HER-2 expression. For each case, three of 3 slides stained appropriately within a run and for all instrument platforms tested. Users verify within run reproducibility results by staining several sets of serial sections with low, medium and high antigen density in a single run. 16 Inter-run and inter-platform reproducibility of staining was determined by staining three slides each of five breast cancer tissues with scores of 0, 1+, 2+, and 3+ HER-2 expression on three different instrument runs across the NexES, BenchMark, and BenchMark XT instrument platforms. For each case, nine of 9 slides stained appropriately over three instrument runs and across all instrument platforms tested. Users should verify between run reproducibility results by staining several sets of serial sections with low, medium and high antigen density on different days. Comparisons studies of three laboratories, from separate institutions in the United States, participated in the inter-laboratory reproducibility study. Cut slides of 40 neutral buffered formalin-fixed invasive breast carcinoma cases [10 each from each HER-2 binning category (0-1+, 2+, 3+)] and six (6) PATHWAY HER-2 4 in 1 Control Slides were shipped to each of the sites for staining on a VENTANA BenchMark XT automated slide staining device using the recommended staining protocol. Controls included the PATHWAY HER-2 4 in 1 Control Slides and a second slide of each case stained with negative Ig reagent. No sites experienced invalid runs, based upon the performance of the controls. The results were analyzed by Ventana. Thirty-four of forty (34/40) slides exhibited similar staining intensity across staining sites. Six samples (6/40 or 15%) varied by no more than 1 intensity level. Three (3/6) samples varied between 0 and 1+, which are both considered to be negative. Two samples (2/40 or 5%) varied between 2+ and 3+, and one sample (1/40) varied between 1+ and 2+. In all of the 40 cases (100%), a minimum of 2 of 3 pathologists agreed.
17 Lot-to-Lot reproducibility was determined by automated staining of 5 breast cancer tissues with scores of 0, 1+, 2+, and 3+ HER2 expression with 3 lots of PATHWAY HER2 (4B5). Stained tissues were scored on a 0 to 3+ scale by three qualified readers. There was 100% agreement between lots and readers for the 3 slides and 5 tissues stained. Comparison Studies to other clones were performed by review of PATHWAY HER2 (4B5) rabbit monoclonal antibody to PATHWAY HER-2 (CB11) mouse monoclonal antibody: Summary of Studies Performed. A method comparison study was conducted to examine the correlation of PATHWAY HER2 (4B5) to PATHWAY HER-2 (CB11) and PathVysion Her-2 FISH, both previously approved FDA diagnostic tests. Six investigators participated in the study. Two sets of three different investigators evaluated two independent cohorts (Cohort 1: n=144, Cohort 2: n=178) using known breast cancer cases stained with HER-2 CB11 and HER2 4B5. FISH data was obtained from patient history. A consensus score from the three readers for each antibody was created for each case to reduce intra-reader variability known to exist with HER-2 scoring.22,23,24 A total of 322 cases were evaluated. The slides stained with PATHWAY HER-2 (CB11) were processed and stained according to the manufacturer s instructions specified in the VENTANA CB11 package insert. Inter-pathologist Reproducibility of Detection Comparison Study Specimens: Positive and negative agreement rates with two-sided score 95% confidence intervals were calculated for the six possible pair-wise comparisons between readers for each method. Inter-pathologist Reproducibility of Detection Comparison Study Specimens: Positive and negative agreement rates with two-sided score 95% confidence intervals were calculated for the six possible pairwise comparisons between readers for each method. 17 Conclusion: Data from the above studies indicated that the PATHWAY HER2 (4B5) primary antibody was specific and reproducible in its ability to locate appropriate membrane staining for normal and neoplastic tissues. The method comparison data demonstrated that PATHWAY HER2 (4B5) primary antibody is indicated as an aid in the assessment of breast cancer patients for whom Herceptin treatment is considered. Complete statistical data on comparison studies are contained within the Pathway Her2 specifications sheet.
18 Table 3. Verification-Validation of PATHWAY HER2 (4B5), Breast Tissue Case # DOB Sex Tissue Pathology Fixation % Tumor Score S F Invasive mammary CA with lobular features 28 hours S F Invasive ductal carcinoma 8 hours S F Invasive poorly differentiated ductal 6.5 hours S F Invasive moderately differentiated ductal 29 hours S F Invasive poorly differentiated ductal 9.5 hours S F Invasive ductal carcinoma 5 hours S F Poorly differentiated ductal carcinoma 6 hours S F Invasive moderately ductal carcinoma 7 hours S F Invasive ductal adenocarcinoma 27 hours S F Invasive mammary carcinoma 8 hours S F Invasive ductal carcinoma 6 hours S F Invasive ductal adenocarcinoma 27 hours S F Invasive mammary carcinoma 25.5 hours S F Invasive moderately differentiated ductal 5 hours S F Invasive ductal with extensive intraductal component 18 hours S F Invasive ductal carcinoma with lobular features 48 hours S F Invasive ductal carcinoma 58 hours S F Invasive ductal Adenocarcinoma and ductal in situ 7.5 hours S F Invasive ductal carcinoma 19 hours S F Invasive moderately differentiated ductal 56 hours S F Poorly differentiated metastatic carcinoma 28 hours S F Invasive poorly differentiated ductal 30 hours S F Invasive ductal carcinoma 6 hours S F Poorly differentiated ductal carcinoma 7 hours S F Invasive ductal carcinoma 24 hours S F Invasive ductal carcinoma 6 hours S F Invasive ductal carcinoma 27.5 hours S F Invasive ductal carcinoma UK S F Invasive mucinous carcinoma 3 hours S F Invasive ductal 27 hours S F Invasive ductal carcinoma 7 hours S F Invasive well differentiated ductal carcinoma 9 hours S F Invasive ductal carcinoma 7 hours S F Invasive solid duct carcinoma, with associated ductal carcinoma in situ 58 hours S F Infiltrating ductal carcinoma UK S F Poorly differentiated ductal carcinoma 30 hours Dates of slide staining of individual slides for inter-run reproducibility comparison are shown in the Ultra run reports. Reagent lots for each run are also recorded with the stain run reports. 18
19 Concordance Summary Statement: The optimization and validation results for the PATHWAY HER2 (4B5) have been reviewed. It has been determined that the performance of the assay under our laboratory conditions, reliably displays the expected pattern of reactivity in normal and diseased tissues consistent with its intended use. It is determined to be suitable for patient testing. Approved: Date: Diagnostic % specificity = 100 x the number of diseased patients with a negative test (divided by) the total number of patients without the disease Diagnostic % sensitivity = 100 x the number of diseased patients with a positive test (divided by) the total number of patients tested Precision is assessed by repeated staining of same positive/negative controls 19
20 DRAFT EXAMPLE OF IHC STAINING PROCEDURE, LEICA ORACLE STAINING SYSTEM Title: Bond Oracle HER2 IHC Staining System Author: Joelle Weaver MAOM, HTL (ASCP) QIHC Date 5/27/2014 Principle Immunohistochemical staining techniques are used to demonstrate the presence of antigens in cells and tissues. Immunohistochemistry is a multi-step procedure based on the attractive forces between antibodies and antigens producing visualization using ordinary light microscopy. Immunohistochemistry is widely utilized within surgical pathology and serves as an adjunctive and diagnostic clinical tool. Purpose This document outlines the procedure for Bond Oracle Her2 IHC staining system, product code TA9145, for use in the staining of 60 tests (150 slides). The Bond Staining run can be completed in approximately 3 hours 20 minutes excluding tissue section-slide preparation time. Description and Intended Use The Bond Oracle Her2 staining system is a semi-quantitative immunohistochemical assay to determine Her2 (human epidermal growth factor receptor 2) Oncoprotein status in breast cancer tissues processed for examination by a pathologist. The results of the Bond Oracle system are indicated as an aid in the assessment of patients for whom Herceptin (Trastuzmab) treatment is being considered. The Bond Oracle system contains the mouse monoclonal anti-her2 antibody, clone CB11. Clone CB11 (Novocastra) is directed against the internal domain of the Her2 Oncoprotein. The Her2 Oncoprotein is expressed at levels detectable by immunohistochemistry in up to 20% of adenocarcinomas from various sites. Software Upgrade Use of the Oracle staining system requires software version 5.0 (BDD 51, software 5.0, CPV # A, service tag # 555D441), of the Bond operating system. A Software upgrade has been performed by a Leica certified engineer with assistance from a Leica antibody staining specialist on 4/21/14, Leica instrument # M Migration of staining protocols, inventory and other stored database information has been verified in a validation-performance test run using the validated CD3 stain protocol and ( 15) suitable tonsil tissue sections. Results of the test run were satisfactory with no staining errors, software errors and all slides staining appropriately. Records of the upgrade verification and test slides are retained in the validation records located on shelf 2 I room # 306. Training of the technical staff on the software was completed during installation by the Leica staining specialist. 20
21 Specimens This procedure applies only to specimens fixed in neutral buffered formalin (10% NBF) when used for clinical-diagnostic use. Only validated stain protocols are used for staining patient tissue sections. Tissue sections should be sectioned at 3-4 microns thickness and placed on appropriate control slides. All control materials for use in immunohistochemical assays are prepared with FFPE tissues. Smears or other cell preparations which have been fixed in 100% ethanol or methanol may be immunostained with tissue staining procedures, but the results obtained have not been validated for clinical use. Decalcified Tissue When staining is performed on decalcified tissue samples (especially breast tissue immunohistochemistry for Er, Pr, and Her 2); or if Fluorescent in-situ hybridization (FISH) or chromogenic in-situ hybridization (CISH) are performed on decalcified samples, the following disclaimer is included in the pathology report. This assay has not been validated on decalcified tissues. Results should be interpreted with caution given the likelihood of false negativity on decalcified specimens. 21 Safety The chromogen, 3, 3 -Diaminobenzidine (DAB), is a known carcinogen and appropriate personal protective equipment is required when handling this reagent. Sodium Azide is a commonly used preservation of antibodies in solution. It is a known carcinogen. Xylene is a strong solvent that acts as a neurotoxin, avoid direct skin contact and use non-latex gloves when using this reagent. Use the expected care needed to safely handle microtome blades. Dispose of used blades in the blade dispenser or sharp s container. Broken slides must be disposed of in the sharp s container. Regulation Manufacturers of commercial immunohistochemistry assay reagents, kits, instruments and computer software are federally regulated with requirements based on risk level classification. In Vitro Diagnostic use devices (IVD), which includes many manufactured products for use in immunohistochemistry, are under the authority of 21CFR Many of the antibodies used by laboratories for immunohistochemistry may also be classified as analyte specific reagents (ASR) by the Food & Drug Administration, (FDA). For Class I analyte-specific reagents (ASRs) the patient report contain the federally regulated disclaimer; This test was developed and its performance characteristics determined by this
22 laboratory. It has not been cleared or approved by the U.S. Food and Drug Administration. The Bond Oracle Her2 system is approved by the FDA for IVD use. Dilution and Preparation All reagents are formulated specifically for use with this assay and lot numbers are specific for each Bond Oracle Her2 staining system. No changes are necessary, and changes from this manufacturer s configuration will invalidate the assay. The pretreatment and staining protocol are predetermined and cannot be altered by the user (IHC protocol H, ER1 for 25 minutes at 97 degrees Celsius). The Bond Oracle staining system (TA9145) contains components required to complete immunohistochemistry on formalin-fixed, paraffinembedded tissue sections. The tissue sections are incubated in the RTU primary Her2 antibody (clone CB11) using the detection by compact polymer technology. The enzymatic conversion of the subsequently added chromogen (DAB), results in the formation of a visible reaction product at the antigenic sites. The results are interpreted by a qualified pathologist via light microscopy. Bond Polymer Refine Detection uses a novel polymerization technology to prepare polymeric horse radish peroxidase linked antibody conjugates. This type of detection does not use streptavidin and biotin, so non-specific staining is not produced from endogenous biotin. Kit Components The kit provides sufficient reagents to stain 150 slides (60 test slides, 60 negative controls, 15 vendor supplied control cell line slides, and 15 in house positive tissue controls). The number of tests is based on the standard usage and provides for a maximum of 15 runs. Optimal usage is obtained when at least 4 slides are stained simultaneously on each slide staining tray. 22
23 Component Her2 control slides ( 15) Her2 primary antibody, 13.5ml Her2 negative control, 9ml Peroxide block, 22.5ml Post primary,22.5ml Polymer,22.5ml DAB part 1, 2.25ml DAB part 2, 22.5ml (x2) Hematoxylin, 22.5ml Description Sections of FFPE human breast cancer cell lines that demonstrate Her2 expression at 0, 1+, 2+ and 3+. RTU, affinity purified mouse monoclonal IgG antibody, clone CB11 RTU mouse IgG at a concentration equivalent to the concentration of the Her2 primary 3-4% hydrogen peroxide Rabbit-anti-mouse IgG Poly-HRP goat, anti-rabbit IgG Chromogen in 0.1% hydrogen peroxide in stabilizer solution Diluted in 0.1% hydrogen peroxide ( v/v) 0.1% Hematoxylin 23 All reagents supplied within the Oracle kit are formulated specifically for use with this assay and lot numbers are specific for each Bond Oracle staining system. The kit components are not sold separately. No substitutions are made to any component or stain results are considered invalid. The kit is stored at 2-8 degrees Celsius when not in use. Return to refrigeration immediately after use. Do not freeze. Other Reagents and Required Materials Immuno-staining instrumentation Leica Bond Max serial # M211887, Refine detection kit catalog # DS9800, primary antibody ( RTU or concentrated),antigen retrieval solution 1 catalog # AR9961& antigen retrieval solution # 2 catalog # AR9640, Bond Dewax solution catalog # AR92222, Bond Wash buffer catalog # AR9590, xylene Stat lab # reagent absolute ethanol Stat lab # , mounting media Cytoseal XL American Mastertech # , glass slides ( various vendors, must be positively charged), glass cover slips, antibody diluent #AR 9352, Scilogix calibrated pipettes, control tissue and/or blocks, distilled water, cover tiles # S and slide racks for the Leica Bond Max immunostainer.
24 Storage Conditions for Reagents not within the Oracle Kit Antibody Diluent AR9352, refrigerate at 2-8 ᴏ C. Concentrated and ready-to-use primary antibodies refrigerate at 2-8 ᴏ C. Refine detection DS9800, Antigen retrieval solution 1 AR9661 & antigen retrieval solution 2 AR 9640, Bond Wash solution AR9590 for long term storage at 2-8 ᴏ C. Bond Dewax solution AR9222 is stored at room temperature. Reagent ethanol and xylene used with slide preparation is stored in flammable storage at room temperature. Temperature fluctuations are monitored continuously during performance of technical procedures, and corrective measures are taken as appropriate. Temperature and humidity are recorded at least once daily on the quality control logs. Corrective actions are made when conditions fall outside of acceptable ranges. Corrective actions are recorded in the quality control records. Refine Detection Leica DS degrees Celsius when not is use Bond Wash Leica AR degrees Celsius when not is use Bond Retrieval Solution 1 Leica AR degrees Celsius when not is use Bond Retrieval Solution 2 Leica AR degrees Celsius when not is use 24 Bond Dewax Leica AR9222 Room temperature All RTU and Concentrated Antibodies Individual order numbers for each ( see procedure and inventory) 2-8 degrees Celsius when not is use