The reliability of rabbit monoclonal antibodies in the immunohistochemical assessment of estrogen receptors, progesterone receptors, and HER2 in human breast carcinomas

Evaluation of trophoblast cell surface antigen-2 (TROP2) protein expression in chemotherapy-resistant and metastatic breast carcinomas

Trophoblast cell-surface antigen 2 (TROP2), a transmembrane receptor expressed in many carcinomas, is a target for novel antibody-drug conjugates such as sacituzumab govitecan. TROP2-targeted therapy is used for unresectable locally advanced or metastatic triple-negative and hormone receptor-positive, HER2-negative breast cancers. The role of TROP2 as a predictive marker is yet unclear. Standardized interpretation criteria for TROP2 immunohistochemistry (IHC) are lacking. Here, we compared three antibody clones and two methods for semi-quantitative assessment, aiming to establish reproducible evaluation criteria. First, TROP2 IHC was performed on normal tissues and nine breast cancers, using the BSB-148, EPR20043 and SP293 clones. EPR20043 was selected for subsequent evaluation in 69 breast cancers without pathological complete response to neoadjuvant chemotherapy (NAC). Four pathologists applied the ASCO/CAP guidelines for HER2 IHC testing (designated as the 'membrane score') and the H-score. All H-scores were categorized as low (0-100), intermediate (101-200) and high (201-300). Although the membrane scores strongly correlated with the categorized H-scores, the latter showed higher interobserver variability. Next, TROP2 IHC was performed on 94 breast cancer metastases and evaluated by six pathologists, confirming the strong correlation between the membrane scores and H-scores. In metastases, the interobserver variability was similar for both methods. Our observations support the application of the HER2 ASCO/CAP guidelines for semi-quantitative evaluation of membranous TROP2 protein expression, as this method strongly correlates with the H-score and is less prone to interobserver variability in post-NAC breast resections. Future studies should investigate the association between the TROP2 membrane score and response to TROP2-targeted therapy.

Immunohistochemical Performance of Estrogen and Progesterone Receptor Antibodies on the Dako Omnis Staining Platform: Evaluation in Multicenter Studies

The analysis of estrogen receptor (ER) and progesterone receptor (PR) expression levels by immunohistochemistry is an important part of the initial evaluation of breast cancer and critically important in treatment planning. Anti-ERα (clone EP1) and anti-PR (clone PgR 1294) antibodies are in development for the Dako Omnis automated staining platform. These antibodies are not yet commercially available and are in performance evaluation, including the 4 international, multicenter studies reported here. For each antibody, a reproducibility study and a method comparison study was done in a randomized manner in order to test the antibodies under conditions closest to real-world user conditions. The reproducibility studies included 5 staining runs on the Dako Omnis with 20 formalin-fixed and paraffin-embedded human breast carcinoma specimens in 3 independent laboratories, and the method comparison studies included several hundred specimens stained on the Dako Omnis and on the Autostainer Link 48 platforms. Stained slides were evaluated for nuclear ER or PR expression according to American Society of Clinical Oncology/College of American Pathologists guidelines (≥1% cut-off for positive) by pathologists who were blinded from the staining method and specimen ID. For both anti-ERα (clone EP1) and anti-PR (clone PgR 1294) on the Dako Omnis, high reproducibility agreement rates were obtained on the interrun, interlaboratory, and interobserver endpoints. High concordance rates were observed between the specimens stained on the Dako Omnis platform and the Autostainer Link 48 platform. Staining quality was excellent for both anti-ERα (clone EP1) and anti-PR (clone PgR 1294) on the Dako Omnis. These results suggest that these antibodies are reliable and reproducible tools for immunohistochemistry analysis of ER and PR expression levels in formalin-fixed and paraffin-embedded breast carcinoma tissues on the Dako Omnis platform.

Comparison of Estrogen and Progesterone Receptor Antibody Reagents Using Proficiency Testing Data

CONTEXT

- Immunohistochemical analysis of estrogen receptor (ER) and progesterone receptor (PgR) expression in breast cancer is the current standard of care and directly determines therapy. In 2010 the American Society of Clinical Oncology and the College of American Pathologists (ASCO/CAP) published guidelines for ER and PgR predictive testing, encompassing preanalytic, analytic, postanalytic factors; antibody validation; and proficiency testing.

OBJECTIVE

- To compare the performance of different antibody reagents for ER and PgR immunohistochemical analysis by using CAP proficiency testing data.

DESIGN

- The CAP PM2 survey uses tissue microarrays of ten 2-mm cores per slide. We analyzed survey data from 80 ER and 80 PgR cores by antibody clone from more than 1200 laboratories.

RESULTS

- Laboratories used the ER antibodies SP1 (72%), 6F11 (17%), 1D5 (3%), and the PgR antibodies 1E2 (61%), 16 (12%), PgR-636 (13%), PgR-1294 (8%) in 2015. While 63 of 80 ER cores (79%) were scored similarly using each of the 3 antibodies, there were significant differences for others, with SP1 yielding more positive interpretations. Four cores were scored as ER negative by more than half of the laboratories using 1D5 or 6F11, while SP1 produced positive results in more than 70% of laboratories using that antibody. Despite the greater variety of PgR antibody reagents and greater PgR tumor heterogeneity, 61 of 80 cores (76%) were scored similarly across the 4 PgR antibodies.

CONCLUSIONS

- Accurate ER and PgR testing in breast cancer is crucial for appropriate treatment. The CAP proficiency testing data demonstrate differences in staining results by ER clone, with SP1 yielding more positive results.

The Importance of Epitope Density in Selecting a Sensitive Positive IHC Control

Clinical Immunohistochemistry (IHC) laboratories face unique challenges in performing accurate and reproducible immunostains. Among these challenges is the use of homemade controls derived from pathological discard samples. Such positive controls have an unknown number of analyte molecules per cell (epitope density). It is unclear how the lack of defined analyte concentrations affects performance of the control. To address this question, we prepared positive IHC controls ( IHControls) for human epidermal growth factor receptor type II (HER-2), estrogen receptor (ER), or progesterone receptor (PR) with well-defined, homogeneous, and reproducible analyte concentrations. Using the IHControls, we examined the effect of analyte concentration on IHC control sensitivity. IHControls and conventional tissue controls were evaluated in a series of simulated primary antibody reagent degradation experiments. The data demonstrate that the ability of a positive IHC control to reveal reagent degradation depends on (1) the analyte concentration in the control and (2) where that concentration falls on the immunostain's analytic response curve. The most sensitive positive IHC controls have analyte concentrations within or close to the immunostain's concentration-dependent response range. Strongly staining positive controls having analyte concentrations on the analytic response curve plateau are less sensitive. These findings emphasize the importance of selecting positive IHC controls that are of intermediate (rather than strong) stain intensity.

Analytic Response Curves of Clinical Breast Cancer IHC Tests

An important limitation in the field of immunohistochemistry (IHC) is the inability to correlate stain intensity with specific analyte concentrations. Clinical immunohistochemical tests are not described in terms of analytic response curves, namely, the analyte concentrations in a tissue sample at which an immunohistochemical stain (1) is first visible, (2) increases in proportion to the analyte concentration, and (3) ultimately approaches a maximum color intensity. Using a new immunostaining tool ( IHControls), we measured the analytic response curves of the major clinical immunohistochemical tests for human epidermal growth factor receptor type II (HER-2), estrogen receptor (ER), and progesterone receptor (PR). The IHControls comprise the analytes HER-2, ER, and PR at approximately log concentration intervals across the range of biological expression, from 100 to 1,000,000 molecules per test microbead. We stained IHControls of various concentrations using instruments, reagents, and protocols from three major IHC vendors. Stain intensity at each analyte concentration was measured, thereby generating an analytic response curve. We learned that for HER-2 and PR, there is significant variability in test results between clinical kits for samples with analyte concentrations of approximately 10⁴ molecules/microbead. We propose that the characterization of immunostains is an important step toward standardization.

A meta-analysis on concordance between immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) to detect HER2 gene overexpression in breast cancer

BACKGROUND

We performed this meta-analysis study to evaluate the concordance and discordance between immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) in detecting HER2 alteration in human breast cancer.

METHODS

As a meta-analysis, the present study evaluated the available data from previous studies on the HER2 gene detected by IHC and FISH. To indicate the meta-analysis results, a forest plot was used.

RESULTS

We identified 172 citations, for which our inclusion criteria were met by 18 articles, representing 6629 cases. The overall concordance and discordance rate between IHC staining with score 0/1+ and FISH for detection failure of HER2 expression was 96 and 4 %, respectively. The present study showed that the overall proportion of FISH positive and negative rate for IHC score 2+ for detection of HER2 expression was 36 and 64 %, respectively; and 91 and 9 % for 3+ IHC scores.

CONCLUSION

The results of this study show that IHC score 0/1+ and 3+ cannot be completely considered as negative and positive breast cancer test, respectively. Therefore, we suggest a valid and complementary test, the same as FISH, to explore HER2 expression.

Measurement of Domain-Specific HER2 (ERBB2) Expression May Classify Benefit From Trastuzumab in Breast Cancer

BACKGROUND

Studies have shown that antibodies targeting the intracellular (ICD) or extracellular domains (ECD) of human epidermal growth factor receptor 2 (HER2) are equivalent when traditional methods are used. We describe a new method to quantify ICD and ECD expression separately and assess the prognostic value of domain-specific HER2 results in patients who received adjuvant trastuzumab therapy.

METHODS

We measured HER2 protein expression with quantitative immunofluorescence (QIF) in tissue microarrays (TMA) using two different antibodies targeting the ICD (CB11 and A0485) and ECD (SP3 and D8F12). We assessed the prognostic value of ICD and ECD expression in 180 patients from a clinical trial of adjuvant chemotherapy followed by trastuzumab (HeCOG 10/05). We performed an exploratory univariate domain-specific, disease-free survival (DFS) analysis and compared DFS functions with Kaplan-Meier estimates. All statistical tests were two-sided.

RESULTS

HER2 ICD expression by QIF showed slightly higher sensitivity to predict ERBB2 (HER2) gene amplification than ECD expression, which was more specific and had higher positive predictive value. In the HeCOG 10/05 trial specimens, 15% of cases showed discordant results for ICD and ECD expression. High ECD was statistically associated with longer DFS (log-rank P = .049, HR = 0.31, 95% CI = 0.144 to 0.997), while ICD status was not. Among patients with low ECD, there was no difference in DFS by ICD status. However, when ICD was high, high ECD was statistically associated with longer DFS (log-rank P = .027, HR = 0.23, 95% CI = 0.037 to 0.82) compared with low ECD.

CONCLUSION

Quantitative measurements of HER2 ICD and ECD expression in breast cancer suggest a subclassification of HER2-positive tumors. Trastuzumab-treated patients with high ECD showed better DFS than patients with low ECD. This suggests differential benefit from trastuzumab therapy based on HER2 ECD expression.

HER2 assessment by silver in situ hybridization: where are we now?

HER2 testing in breast and gastric cancer is critical not only as a prognostic tool but also as a predictive marker for response to the humanized monoclonal antibody trastuzumab. Currently, HER2 status is assessed on histological and cytological specimens by conventional validated methods such as immunohistochemistry and FISH, while bright-field in situ hybridization techniques, such as silver in situ hybridization and chromogenic in situ hybridization, may offer performance benefits over FISH. The major points are first, technical issues, advantages and disadvantages relevant to each methods, and their clinical implications and second, the well-known genetic heterogeneity of HER2, and the occurrence of polysomy of chromosome 17. This review aims to summarize the growing body of literature on the accuracy of bright-field in situ techniques, notably silver in situ hybridization, in assessing HER2 status, and to discuss the role of such methods in pathology practice.

Risk of contralateral second primary breast cancer according to hormone receptor status in Germany

INTRODUCTION

Hormone receptor (HR) status has become an established target in treatment strategies of breast cancer. Population-based estimates of contralateral breast cancer (CBC) incidence by HR subtype in particular are limited. The aim of this study was to provide detailed data on CBC incidence for Germany.

METHODS

Invasive breast cancer data were extracted on 49,804 women yielding 594 second primaries from the cancer registries of the Federal States of Brandenburg and Saarland and the area of Munich for the period from 1998 to 2007. Multiple imputation was used on missing values for HR status. We estimated standardized incidence ratios (SIRs) with 95% confidence intervals (95%CIs).

RESULTS

SIR estimates of CBC among women diagnosed with an invasive first primary breast cancer (FBC) of any HR subtype ranged from 1.0 to 1.5 in the three registries. Pooling three registries' data, the SIR of HR-positive CBC was 0.7 (95%CI: 0.6 to 0.8) among women with HR-positive FBC. For those women with HR-negative FBC, the SIR of HR-negative CBC was 8.9 (95%CI: 7.1 to 11.1). Among women with FBC diagnosed before the age of 50 years, incidence of CBC was increased, especially for HR-negative FBC (SIR: 9.2; 95%CI: 7.1 to 11.9).

CONCLUSIONS

HR status of the first primary and age at first diagnosis is relevant for predicting risk of CBC. Particularly, patients with HR-negative FBC had elevated risks.

Loss of PTEN expression is associated with IGFBP2 expression, younger age, and late stage in triple-negative breast cancer

OBJECTIVES

To investigate the association between PTEN loss and IGFBP2 expression in a series of triple-negative breast cancers and to relate this expression to basal cytokeratin expression and clinicopathologic features.

METHODS

One hundred and one formalin-fixed and paraffin-processed triple-negative breast cancer cases from the University of Malaya Medical Centre were tested immunohistochemically for cytokeratins 5/6 and 14, PTEN, and IGFBP2. The resulting slides were scored for proportion and intensity of staining.

RESULTS

Loss of tumor nuclear and cytoplasmic staining for PTEN occurred in 48.3% of cases and was significantly associated with younger age at diagnosis (47 years compared with 57 years in those without PTEN loss; P = .005). Independent predictors of PTEN loss were late stage at presentation (P = .026), cytokeratin 5/6 positivity (P = .028), and IGFBP2 expression (P = .042). High levels of IGFBP2 expression were seen in 32% of cases; an independent predictor of high levels was cytokeratin 14 negativity (P = .005). PTEN loss and high levels of IGFBP2 expression were associated with poorer survival, but neither of these trends was significant.

CONCLUSIONS

PTEN loss is a frequent event in triple-negative breast cancers and is significantly associated with younger age at onset of breast cancer, late stage, and IGFBP2 expression.

The prevalence of immunohistochemically determined oestrogen receptor positivity in primary breast cancer is dependent on the choice of antibody and method of heat-induced epitope retrieval - prognostic implications?

BACKGROUND

Oestrogen receptor (ER) status is important for the choice of systemic treatment of breast cancer patients. However, most data from randomised trials on the effect of adjuvant endocrine therapy according to ER status are based on the cytosol methods. Comparisons with immunohistochemical methods have given similar results. The aim of the present study was to examine whether different ER antibodies and heat-induced epitope retrieval (HIER) methods influence the prevalence of ER-positivity in primary breast cancer.

MATERIAL AND METHODS

This study is based on patients included in a clinical trial designed to compare the effect of two years of adjuvant tamoxifen versus no adjuvant systemic treatment in premenopausal women. From 1986 to 1991, 564 patients from two study centres in Sweden were enrolled and randomised. Patients were randomised independently of ER status. In the present study, ER status was assessed on tissue microarrays with the three different ER antibody/HIER combinations: 1D5 in citrate pH 6 (n = 390), SP1 in Tris pH 9 (n = 390) and PharmDx in citrate pH 6 (n = 361).

RESULTS

At cut-offs of 1% and 10%, respectively, the prevalence of ER-positivity was higher with SP1 (75% and 72%) compared with 1D5 (68% and 66%) and PharmDx (66% and 62%). At these cut-offs, patients in the discordant groups (SP1-positive and 1D5-negative) seem to have a prognosis intermediate between those of the double-positive and double-negative groups. Comparison with the ER status determined by the cytosol-based methods in the discordant group also showed an intermediate pattern. The repeatability was good for all antibodies and cut-offs, with overall agreement ≥ 93%.

CONCLUSION

The present study shows that the choice of antibody and HIER method influences the prevalence of ER-positivity. We suggest that this be taken into consideration when choosing a cut-off for clinical decision making.

Immunohistochemical analysis of the monoclonal antibody 4B5 in breast tissue expressing human epidermal growth factor receptor 4 (HER4)

AIMS

A recent study examining the specificity of human epidermal growth factor receptor (HER) 2 pharmacodiagnostic antibodies demonstrated that CB11 and 4B5 stain both HER2-transfected and HER4-transfected cell lines. However, there has been no evidence showing that 4B5 has affinity for HER4 in clinically obtained tissues, and, if so, whether this has any impact on the assessment of HER2. We therefore sought to determine the expression of membrane-bound HER4 in clinical breast carcinomas, and evaluate its impact on the clinical utility of 4B5 in determining HER2 status.

METHODS AND RESULTS

Breast carcinomas were assessed by immunohistochemistry (IHC) for membrane-bound HER4 using anti-HER4 clone E200. HER2 expression in these cases was then assessed using anti-HER2 clone 4B5, and a reference clone, SP3. In all 117 membrane HER4-positive cases (out of 241), 4B5 scored equal to or less than the reference anti-HER2 clone SP3. Eighteen cases were positive for membrane-bound HER4 by E200 and negative by 4B5, including a membrane HER4 level 3+ case.

CONCLUSIONS

No cross-reactivity of 4B5 with membrane-bound HER4 was identified in the clinical IHC analysis of formalin-fixed paraffin-embedded breast carcinoma cases as evidenced by the HER4 antibody clone E200.

False positivity in HER2 testing of breast cancer: novel paths for approaching an old dilemma

AIMS

Variability in determining HER2 status has been reported, especially, differences in sensitivity and specificity among commercially available antibodies, with false positive and false negative results. We compared the sensitivity and specificity of five anti-HER2 antibodies by immunohistochemistry (IHC), using the new dual colour brightfield in situ hybridisation (DDISH) as the gold standard, on invasive breast carcinomas (IBC) arrays.

MATERIAL AND METHODS

Serial sections from tissue microarrays (TMA) containing 200 preselected primary IBC were submitted to DDISH (VENTANA INFORM HER2 Dual ISH assay), and immunohistochemistry, using Dako A0485 and HercepTest (polyclonal), Novocastra CB11 (mouse monoclonal), NeoMarkers SP3 and Ventana 4B5 (rabbit monoclonal).

RESULTS

From the initial 200 cases, 184 were assessed by DDISH and IHC. The concordance among the antibodies was considered very good (kappa statistics varied from 0.82 to 0.9). The overall concordance between IHC and DDISH ranged from 94.1% for CB11 to 96.6% for A0485. The antibodies A0485, HercepTest, SP3 and 4B5 were over 95% sensitive and specific. CB11 was the most specific antibody (97.1%). 60% (CB11) to 83.3% (SP3) of the 2+ cases showed no gene amplification by DDISH. False negative cases varied from 0.5% (A0485) to 3.8% (CB11) of the cases, and false positive from 1.6% (CB11) to 2.7% (HercepTest, SP3 and 4B5) of the 184 cases.

CONCLUSIONS

There was very good agreement among the five anti-HER2 antibodies. CB11 was the most specific antibody, but showed more false negative cases. A0485, SP3, 4B5 and HercepTest were highly sensitive and specific, but showed more false positive cases.

Divisional role of quantitative HER2 testing in breast cancer

BACKGROUND

Human epidermal growth factor receptor 2 (HER2) is amplified in human breast cancers in which therapy targeted to HER2 significantly improves patient outcome. We re-visited the use of real-time quantitative polymerase chain reaction (qPCR)-based assays using formalin-fixed paraffin-embedded (FFPE) tissues as alternative methods and investigated their particular clinical relevance.

METHODS

DNA and RNA were isolated from FFPE specimens and HER2 status was assessed by qPCR in 249 consecutive patients with primary breast cancer. Concordance with results forg immunohistochemistry (IHC) and in situ hybridization (ISH), clinical characteristics and survival was assessed.

RESULTS

HER2 gene copy number had a stronger correlation with clinicopathological characteristics and excellent concordance with IHC/ISH results (Sensitivity: 96.7 %; concordance: 99.2 %). HER2 gene expression showed inadequate sensitivity, rendering it unsuitable to determine HER2 status (Sensitivity: 46.7 %; concordance: 92.1 %), but lower HER2 gene expression, leading to the classification of many cases as "false negative", contributed to a prediction of better prognosis within the HER2-amplified subpopulation.

CONCLUSION

Quantitative HER2 assessments are suggested to have evolved their accuracy in this decade, which can be a potential alternative for HER2 diagnosis in line with the in situ method, while HER2 gene expression levels could provide additional information regarding prognosis or therapeutic strategy within a HER2-amplified subpopulation.

Immunohistochemistry of deparaffinised sections using antigen retrieval with microwave combined pressure cooking versus immunofluorescence in the assessment of human renal biopsies

BACKGROUND

Immunofluorescence of frozen tissue sections (IF-F) is a traditional technique used in renal biopsy. However, IF-F has certain disadvantages, such as a few or even no glomeruli in the section, and limited long-term preservation of the fluorescently labelled samples.

METHODS

We compared two-step immunohistochemistry (IHC) staining of deparaffinised sections for antigen retrieval with microwave combined high-pressure cooking to IF-F used to detect antigens of IgG, IgA, IgM, C3, C1q, κ and λ in patient renal biopsy samples. The number of glomeruli detected, sensitivity and specificity of positive staining, tissue structure, and location staining of the antigens were determined using the two methods in 285 patients diagnosed with different renal diseases.

RESULTS

Concordant observations between IF-F and IHC were 99% for all antigen staining (1969 of 1995 observations) and 100% for IgG, IgA and IgM (all 285 observations). The number of glomeruli in IHC sections was significantly greater compared with IF-F sections (p<0.001). IHC provided clearer images of tissue structure, more precise localisation of positive-staining antigens, and IHC staining allowed simultaneous evaluation of tissue by light microscopy. Correlation between tissue structure and immune deposits are not readily attained by IF-F.

CONCLUSIONS

IHC is superior to IF-F for immunopathological diagnosis of renal biopsy tissue and is a reliable replacement for the more traditional IF-F method.

SP3, a reliable alternative to HercepTest in determining HER-2/neu status in breast cancer patients

Accurate assessment of HER-2/neu gene status in breast cancer patients has important prognostic and therapeutic implications. Overexpression/gene amplification of HER-2 is associated with a more aggressive clinical course and eligibility for targeted therapy with trastuzumab. A variety of immunohistochemical (IHC) antibodies and in situ hybridisation (ISH) methods have been employed to assess HER-2 status. SP3 is a rabbit monoclonal antibody that has been shown to have a high level of agreement with other anti-HER-2 antibodies and ISH methods. We assessed HER-2 status by SP3 and HercepTest IHC stains and by fluorescence in situ hybridisation (FISH) on invasive breast carcinomas from paired needle core biopsy and excisional biopsy specimens from 100 patients. We compared the two antibodies with respect to concordance rates with FISH, concordance rates between samples of the same tumour, and sensitivity and specificity using FISH as the reference test. Concordance between SP3 and FISH in needle core biopsy and excisional biopsy specimens was 96% (95% CI 91.9% to 99.7%) (κ=0.89 (95% CI 0.73 to 1.00)) and 97% (95% CI 90.3% to 99.3%) (κ=0.84 (95% CI 0.66 to 1.00)), respectively. Sensitivity and specificity of SP3 for detecting HER-2 overexpression/gene amplification were 78.3% and 100%, respectively, in needle core biopsy and excisional biopsy specimens. Concordance between SP3 results assessed on the needle core biopsy and excisional biopsy was 89% (95% CI 81.2% to 94.4%) (κ=0.62 (95% CI 0.42 to 0.82)). Concordance between SP3 and HercepTest antibodies, after excluding 2+ cases, was 97.6% (95% CI 94.0% to 99.3%) (κ=0.88 (95% CI 0.77 to 1.00)). SP3 is a reliable alternative to HercepTest in evaluating HER-2 status in breast cancer patients. Like other anti-HER-2 antibodies, SP3 may serve as a diagnostic tool in breast pathology and has potential utility as an IHC biomarker in non-mammary malignancies.

Immunofluorescence with dual microwave retrieval of paraffin-embedded sections in the assessment of human renal biopsy specimens

Immunofluorescence of frozen tissue sections (IF-F) is a classic technique for renal immunopathologic examination. However, it has certain disadvantages, such as diffuse antigen distribution and few or even no glomeruli in the section. We developed a new technique of immunofluorescence staining using dual microwave retrieval in paraffin-embedded renal tissue sections (IF-DMP) and compared IF-DMP with IF-F in 406 renal biopsy samples. IF-DMP detected significantly more glomeruli than did IF-F (P< .001). There was no significant difference for the specificity and sensitivity in the detection of immunoglobulins, complements, κ, and λ between IF-F and IF-DMP. Concordant observations were 98% for all immunofluorescence, complements, κ, and λ staining and 100% for immunoglobulin staining. Both techniques were completely accurate in confirming diagnoses of various glomerular diseases. IF-DMP provided clearer images of tissue structure and more precise localization of antigens, and it is a suitable alternative for traditional IF-F in clinical renal immunopathologic diagnosis.

Comparison of anti-estrogen receptor antibodies SP1, 6F11, and 1D5 in breast cancer: lower 1D5 sensitivity but questionable clinical implications

We compared the anti-estrogen receptors (ER) SP1, 6F11, and 1D5 antibodies in breast carcinoma cases with different ranges of positive cells to evaluate whether this could generate different therapies for patients. We selected 66 cases of breast cancer, each of which was immunostained with the 3 antibodies. 1D5 was less sensitive than SP1 and 6F11, as seen in 26, 20, and 21 negative cases, respectively. Nine cases showed differences in endocrine-therapy indications, of which 8 1D5-negative cases showed low positivity for SP1 and/or 6F11. However, these cases were prevalently G3, progesterone receptor-negative or low-positive, with high Ki-67 and positive HER-2 findings, all biological features associated with endocrine resistance. Finally ER values obtained with these 3 antibodies had no implications for chemotherapy.

From morphologic to molecular: established and emerging molecular diagnostics for breast carcinoma

Diagnostics in the field of breast carcinoma are constantly evolving. The recent wave of molecular methodologies, both microscope and non-microscope based, have opened new ways to gain insight into this disease process and have moved clinical diagnostics closer to a 'personalized medicine' approach. In this review we highlight some of the advancements that laboratory medicine technology is making toward guiding the diagnosis, prognosis, and therapy selection for patients affected by breast carcinoma. The content of the article is largely structured by methodology, with a distinct emphasis on both microscope based and non-microscope based diagnostic formats. Where possible, we have attempted to emphasize the potential benefits as well as limitations to each of these technologies. Successful molecular diagnostics, applied in concert within the morphologic context of a patient's tumor, are what will lay the foundation for personalized therapy and allow a more sophisticated approach to clinical trial stratification. The future of breast cancer diagnostics looks challenging, but it is also a field of great opportunity. Never before have there been such a plethora of new tools available for disease investigation or candidate therapy selection.