[A 19-year-old female patient with acute pancreatitis of unusual cause]

We report the case of a 19-year-old woman with abdominal pain and diarrhea. The diagnosis of acute pancreatitis could be made clinically and through laboratory tests. The cause was a duodenal duplication cyst in the area of the papilla, which was initially relieved endoscopically. Once the acute inflammation had healed, the cyst was resected endoscopically to prevent recurrence and the increased risk of malignancy. Duodenal duplication cysts in the papillary area are a very rare (congenital) cause of acute pancreatitis. If a cyst is present in the area of the duodenal wall, however, this differential diagnosis should be considered. Resection is indicated for therapy.

Technical note: Automatic evaluation of infrared thermal images by computerized active shape modeling of bovine udders challenged with Escherichia coli

Mastitis causes substantial economic losses and animal suffering in the dairy industry. The trend toward larger herd sizes complicates the monitoring of udder health in individual animals. Infrared thermography has successfully been used for early mastitis detection. However, manual thermogram analysis is time consuming and requires a skilled examiner, and automated image processing has not been tested. The aim of this study was to determine whether automatic evaluation of thermograms showed results comparable to those of manual evaluation of thermograms. Five healthy cows underwent an intramammary challenge with Escherichia coli to induce clinical mastitis. Multiple udder thermograms were taken every 2 h for 24 h before and after the challenge, resulting in 4,143 images in total. All images were evaluated using image recognition software (automatically) and a polygon tool (manually) to calculate the average and maximum surface temperatures. Because of the slightly different regions of interest, temperatures ascertained from the thermograms using the automatic method were consistently lower than those ascertained using the manual method. However, average udder surface temperatures evaluated using both methods were strongly correlated (r = 0.98 in the left hindquarter, and r = 0.99 in the right hindquarter) and showed maximum temperature peaks at the same time, 13 and 15 h after intramammary challenge. In the receiver operating characteristic analysis, both methods provided good results for sensitivity and specificity in detecting clinical E. coli-induced mastitis at different threshold values. For automatically evaluated maximum right hindquarter temperature, sensitivity was 93.75% and specificity was 94.96%, and for manually evaluated maximum right hindquarter temperature, sensitivity was 93.75% and specificity was 96.40%. Thus, automatic thermogram evaluation is a promising tool for automated mastitis detection.

Targeting β-catenin dependent Wnt signaling via peptidomimetic inhibitors in murine chondrocytes and OA cartilage

OBJECTIVE

The canonical Wnt signaling pathway has been shown to be involved in regulating chondrocyte hypertrophic differentiation during Osteoarthritis (OA). The aim of this study was to test the therapeutic potential of two stapled peptide canonical Wnt inhibitors - SAH-Bcl9 and StAx-35R - in preventing Wnt induced cartilage changes in OA.

METHODS

Primary neonatal murine chondrocytes and cartilage explants from OA patients undergoing total joint replacement for knee OA, were used for microscopy to determine matrix and cell penetrating capacity of fluorescein isothiocyanate FITC-tagged SAH-Bcl9 and StAx-35R peptides. T cell factor/lymphoid enhancer-binding factor (TCF/LEF) reporter assays were used to monitor the inhibition of Wnt3a induced β-catenin signaling by each peptide. Changes in chondrocyte phenotypic marker gene expression were analyzed by qRT PCR.

RESULTS

Both peptides localized intercellular in primary murine chondrocytes and cartilage explants. They inhibited Wnt3a induced TCF/LEF promoter activity in primary murine chondrocytes. Both inhibitors did not rescue Wnt3a altered expression of chondrocyte phenotypic genes (Sox9, Col2a1, Acan) and hypertrophy marker gene (Col10a1) at high doses (100 ng/ml). Upon application of 10 ng/ml Wnt3a, StAx-35R partially reversed the Wnt effect on Sox9 and Col2a1 gene expression. Both peptides, however, reversed the downregulation of SOX9 and aggrecan (ACAN), and decrease of COL10A1 gene expression in preserved human OA cartilage explants.

CONCLUSION

These data indicate that blockade of canonical Wnt signaling might be a therapeutic strategy to treat early OA cases and protect further cartilage degradation by preventing chondrocyte hypertrophic differentiation.

Abstract P6-08-06: Neoadjuvant tamoxifen therapy synchronizes ERα binding and gene expression profiles

Background: The majority of breast cancer patients are diagnosed with ERα-positive breast cancer. Most ERα-positive patients are treated with adjuvant endocrine therapy — typically tamoxifen or aromatase inhibitors — to block cellular proliferation. Although these treatments are considered successful, resistance is common. Notably, cross-resistance between the two types of therapies is not always observed suggesting molecular heterogeneity and underlining the need for development of personalized treatments. The Anastrozole, Fulvestrant or Tamoxifen Exposure — Response in molecular profile study (AFTER study, NCT00738777) aims to investigate prospectively whether short-term treatment can induce molecular changes indicative of pre-operative therapy response. Study Design: ERα-positive breast cancer patients are included in this open-label multicenter study. Post-menopausal patients are randomized between tamoxifen, anastrozole and fulvestrant and pre-menopausal and male patients receive tamoxifen. Treatment occurs during the pre-operative window between diagnosis and surgery (4±2 weeks). Clinical characteristics collected are ERα/PR and HER2 status as well as lymph-node status. The primary endpoint is the decrease in tumor cell proliferation, as assessed by Ki67 gene expression and published cell proliferation gene expression signatures. All data are collected from both pre- and post-treatment samples. Additionally, we will compare the changes induced by treatment in gene expression, ERα/DNA binding interactions, DNA copy number, endoxifen and estradiol levels. Results: Among 67 patients currently enrolled, we examined the data from the subset of 28 tamoxifen treated patients. ERα and PR levels did not differ significantly between pre- and post-treatment. All tumors were HER2-negative. Proliferation examined by Ki67 (IHC and gene expression, MKI67) was significantly lower in post-treatment samples (P < 0.01). A significant association was identified with the change in gene expression proliferation signature score and change in MKI67 (rho = 0.7, P < 0.001). We identified two samples, which changed from MammaPrint (MP) low-risk to high-risk among 17 pairs with data. One sample's score was on the cutoff for high-risk definition. Interestingly, the second sample also had an increase in Ki67 gene expression and proliferation gene signature score in the post-treatment sample. Overall, ERα/DNA binding interaction regions overlapped significantly more among post-treatment samples as compared to pre-treatment samples (P <0.001). There were 3 samples that increased in MKI67 gene expression after drug exposure. Among these, only the MP low- to high-risk sample had an increase in proliferation gene signature and decrease in ERα/DNA binding interactions. Conclusions: Pre-treatment samples were more variable for both proliferation gene expression signatures and ERα/DNA binding interactions indicating the underlying molecular heterogeneity of the group prior to therapy. This inter-tumor heterogeneity appears to have been lowered by exposure to tamoxifen. Interestingly, not all samples were uniform in their response to tamoxifen exposure as measured by Ki67 and MP scores suggesting samples taken after treatment exposure may be useful for predictive biomarker discovery.

Citation Format: Linn SC, Severson TM, Nevedomskaya E, Peeters J, van Rossum A, Kuilman T, Krijgsman O, Goossens I, Glas A, Koornstra R, Peeper D, Wesseling J, Simon I, Wessels L, Zwart W. Neoadjuvant tamoxifen therapy synchronizes ERα binding and gene expression profiles. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-08-06.

High concordance of protein (by IHC), gene (by FISH; HER2 only), and microarray readout (by TargetPrint) of ER, PgR, and HER2: results from the EORTC 10041/BIG 03-04 MINDACT trial

BACKGROUND

To investigate the correlation of TargetPrint with local and central immunohistochemistry/fluorescence in situ hybridization assessment of estrogen (ER), progesterone (PgR), and human epidermal growth factor receptor 2 (HER2) in the first 800 patients enrolled in the MINDACT trial.

PATIENTS AND METHODS

Data from local (N = 800) and central (N = 626) assessments of receptor status were collected and compared with TargetPrint results.

RESULTS

For ER, the positive agreement (the percentage of central pathology positive assessments that were also TargetPrint/local laboratory positive) for TargetPrint in comparison to centralized assessment was 98% with a negative agreement (the percentage of central pathology negative assessments that were also TargetPrint/local laboratory negative) of 96%. For PgR, the positive agreement was 83% with a negative agreement of 92%. For HER2, the positive agreement was 75% with a negative agreement of 99%. Even though the local assessment showed higher positive agreement for PgR (89%) and higher positive agreement for HER2 (85%), the range of discordant local versus central assessments were as high as 6.7% for ER, 12.9% for PgR, and 4.3% for HER2.

CONCLUSION

TargetPrint and local assessment of ER, PgR, and HER2 show high concordance with central assessment in the first 800 MINDACT patients. However, there are concerns about the higher discordance rates for some local sites. TargetPrint can improve the reliability of hormone receptor and HER2 testing for those centers with a lower rate of concordance with the reference laboratory, with the limitation of a positive agreement of 75% for HER2. TargetPrint consequently has important implications for treatment decisions in clinical practice and is a reliable alternative to local assessment for ER.

CLINICAL TRIALS NUMBER

NCT00433589.

P1-06-20: Response to Neo-Adjuvant Chemotherapy and Outcomes for I-SPY 1 Patients Stratified by the 70-Gene Prognosis Signature (MammaPrint) and Molecular Subtyping (BluePrint)

Background

Classification of breast cancers into molecular subtypes may be important for the proper selection of therapy for patients as tumors with seemingly similar biology can have strikingly different clinical outcomes. We analyzed response to neo-adjuvant chemotherapy as a function of molecular sub-types and show patient survival from the multi-center neo adjuvant trial, I-SPY I (CALGB 150007/150012; ACRIN 6657). Previous analyses had shown that breast cancer subtypes as identified by immunohistochemistry or molecular analyses, have distinct clinical outcome (Esserman, ASCO 2009). Here, we analyze how the 70-gene signature (MammaPrint) together with an 80-gene molecular subtyping profile (BluePrint=Basal-type, Luminal-type, ERBB2-type; de Snoo, ASCO, 2010 and manuscript under review) can sub-classify patients.

Materials: This study was carried out on genomics data of core needle biopsies from 149 out of 221 patients enrolled in the I-SPY I trial, a multi-center trial designed to identify predictive markers of pathological complete response (pCR) and disease-free survival (DFS) in women with locally advanced breast cancer (3 cm or greater). All women received neoadjuvant Doxorubicin & Cytoxan followed by paclitaxel chemotherapy. The 70-gene and the subtyping signatures, Basal, Luminal and ERBB2-type were determined on 44K Agilent arrays available through the I-SPY 1 data portal (Esserman, ASCO, 2009 and manuscript under review).

Results: The 70-gene signature classified 9% of patients (13/149) as Low Risk, of whom one patient was ERBB2-type, and the other 12 were Luminal-type. None of these patients experienced a pCR. The remaining 136 were classified as 70-gene High Risk (91%), of whom 47% were classified as Luminal-type with a pCR rate of 13%, 41% were Basal-type with a pCR rate of 34%, and 12% were ERBB2-type with a pCR rate of 56%.

Patients with BluePrint Basal-type tumors had a 5-year DFS of 61%; ERBB2-type had a 5-year DFS of 78%; 70-gene High Risk/Luminal-type had a 5-year DFS of 73% and 70-gene Low Risk/Luminal-type showed 5-year DFS of 100%.

The molecular subtype classification shows significant association to clinically assessed receptor status. However, clinically assessed HER2+ patients were distributed across all molecular subtypes, where ER+HER+ are predominantly classified as Luminal-type.

Conclusion: This study was performed with the I-SPY I dataset, which provides a platform to compare, contrast & combine marker signatures to tailor therapy. We show how combining BluePrint, with MammaPrint risk-classification can detect specific groups of patients who are at high risk of recurrence and who would have a higher likelihood to benefit from chemotherapy. Furthermore, MammaPrint Low Risk patients do not benefit from neo-adjuvant therapy, though have excellent survival rates, suggesting that the Low Risk Luminal-type patients could be managed conservatively.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-06-20.

P1-07-06: High Concordance of Protein (by IHC), Gene (by FISH; HER-2 Only) and Microarray Readout (by TargetPrint) of ER/PR/HER2: Results from the MINDACT Trial

Background

Previously, the micro-array readout of ER, PR and HER2 by TargetPrint was shown to be strongly correlated with high quality immunohistochemistry (IHC)/FISH assessment, especially for ER and HER2. Concordance rates were 93% (k=0.79) for ER; 83% (k=0.65) for PR and 96% for HER2 (k=0.88) in 636 patients (Roepman et al., Clin Cancer Res, 2009).

This study analysis was undertaken to further determine the correlation of microarray readout with IHC/FISH assessment both locally and centrally determined in the 1st 800 pts enrolled in the MINDACT trial. This work is essential to determine the quality of biological data in the two risk assessment methods used in MINDACT based upon which adjuvant chemotherapy decision is made, in order to exclude bias.

Methods: ER/PR/HER2 IHC assessment was performed on the 1st 800 primary breast cancers (BC) of pts enrolled in the MINDACT study. The assessment was performed locally at each center (n=800) and by central review at the laboratory of the European Institute of Oncology (n=626). A tumor was classified positive for ER and PR when 1% of tumor cells showed positive staining. HER2 IHC status was scored as 0, 1+, 2+ or 3+; a score of 3+ was considered positive. In 2+ cases FISH was performed to assess final HER2 status. Gene expression data for ER, PR and HER2 were obtained by TargetPrint stratified as receptor positive or negative using previously determined and validated thresholds for ER, PR and HER2 mRNA levels (n=800).

Results: Comparison of local assessment (IHC & FISH for HER2) with central review indicated highly similar results for receptor readout with a concordance of 98% (k=0.90) for ER; and 96% for HER2 (k=0.80) and slightly lower for PR (90% (k=0.72)).

Comparison of central assessment (IHC & FISH for HER2) with micro array readout by TargetPrint indicated highly similar results for receptor readout with a concordance of 97% (k=0.88) for ER and 95% for HER2 (k=0.76). For PR the concordance was lower but still quite acceptable (85% (k=0.62)).

Conclusion: Local and centrally assessed ER, PR and HER2 status in the first 800 MINDACT patient samples indicate a high level of quality for pathology in the local participating hospitals. These results exclude any bias induced by a lower quality of “traditional” pathology results as compared to the centrally assessed MammaPrint, both used for risk assessment and adjuvant chemotherapy decision in the MINDACT trial. The microarray-based assessment of ER, PR and HER2 gives results comparable to IHC & FISH and provides an objective and quantitative assessment of tumor receptor status. These results indicate that TargetPrint can serve as a second pathology assessment for locally assessed parameters, especially since TargetPrint is part of a multi-profile platform for breast cancer treatment management. This work was funded by the Breast Cancer Research Foundation and the EU Framework Program VI.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-07-06.

Combined use of MammaPrint and molecular subtyping profile (BluePrint) to identify subgroups with marked differences in response to neoadjuvant treatment

42

Background: Concordance between the IHC receptor status and the molecular subtype suggests that molecular profiles represent oncogenic processes that are driven by pathways in which ER, PR and HER2 play pivotal roles. It is, therefore, likely that the use of gene expression arrays will enable the identification of previously unappreciated subtypes of breast cancer that differ in clinical outcomes.

Methods: The cohort consists of 133 (T1-4, N0-3) breast cancer patients treated with T/FAC neoadjuvant chemotherapy. Genome wide expression data was publicly available and downloaded from bioinformatics.mdanderson.org/pubdata.html. The data was used to determine the response to T/FAC neoadjuvant chemotherapy for patients stratified by MammaPrint and molecular subtype (BluePrint). The MammaPrint and BluePrint result were used to subtype the patients into 4 groups: MammaPrint Low-risk/Luminal-type, MammaPrint High-risk/Luminal-type, Basal-type and ERBB2-type.

Results: Within this patient cohort, 20% (n=27) were classified as Basal-type, 62% (n=82) as Luminal-type, and 18% (n=24) as ERBB2-type. The overall pCR of this patient cohort was 26% and differed substantially among the subgroups. pCR was observed in 9% of all Luminal-type samples (i.e. 3% of MammaPrint Low Risk/Luminal-type and 11% of MammaPrint High Risk/Luminal-type), in 50% of the ERBB2-type samples and in 56% of the Basal-type samples. The pCR rates observed for the ERBB2-type and Basal-type patient groups were higher compared to classification based on IHC/CISH assessed ER and HER2 receptor status: 50% for ERBB2-type versus 39% for HER2+ and 56% for Basal-type versus 47% for ER-/HER2- samples.

Conclusions: We observed marked differences in response to neo-adjuvant treatment in groups stratified by MammaPrint and BluePrint. These findings confirm differences in chemotherapy response among molecular subgroups and indicate that the BluePrint profile described here will help to further establish a clinical correlation between molecular subtyping and treatment response.

Molecular Subtype Profile Reveals Therapy Predictive Power

BackgroundClassification of breast cancers into molecular subtypes may be important for accurate selection of therapy for patients. Here we report the respective chemotherapy responsiveness of the molecular subtypes profile defined Luminal, ERBB2 and Basal type.MethodsAn 80-gene subtype profile was developed based on a series of 200 samples with concordant ER, PR and Her2 receptor IHC and single gene readout status. Previously we reported the excellent validation of the profile classification using 784 samples. Here we report a second in silico validation consisting of 133 samples (Hess et al, JCO, 2006) which tested the profile as a predictor of pathological Complete Response (pCR) in these patients treated with T/FAC neoadjuvant chemotherapy.ResultsIn the 133 publicly available samples the profile classified 62% (82) as Luminal-type, 18% (24) as ERBB2-type and 20% (27) as Basal-type. These results were consistent with percentages found in the training and validation cohorts (n=1079; 295 training and 784 validation samples); 66% (712) Luminal-type, 18% (194) as ERBB2-type and 16% (173) Basal-type. Chemotherapy response was measured by pathological Complete Response (pCR) at the time of surgery In the Luminal-type subgroup 9% (7) of patients showed pCR, in the ERBB2-type subgroup 50% (12) of patients had a pCR and in the Basal-type subgroup 56% (15) of patients had a pCR.ConclusionsThe developed multi-gene profile can classify breast cancer tumors into Luminal-, ERBB2- and Basal-type subgroups. Within the subgroups, a significant difference in chemotherapy response, as measured by pCR, is observed. Implementation of this knowledge may improve the clinical management of breast cancer patients, by enabling the physician to decide who is most likely to benefit from chemotherapy or endocrine therapy prior to surgery.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6131.

The 70-Gene Profile (MammaPrintTM) Is an Independent Predictor of Breast Cancer Specific Survival for Women 65 Years of Age or Older

Background: One-half of all new breast cancer diagnoses occur in women age 65 years or older. In this age group, the use of adjuvant chemotherapy is largely influenced by co-morbidity and little is known about the applicability of prognostic multi-gene assays. The 70-gene profile (MammaPrint) is an independent prognostic indicator in early breast cancer, however, its performance in women with breast cancer 65 years or older has not been systematically studied.Methods: Women 65 years or older who were diagnosed at the Jules Bordet Institute and the Netherlands Cancer Institute between 1987 and 2003 with primary breast cancer with 0-3 involved lymph nodes who received either no adjuvant systemic therapy or adjuvant hormonal therapy alone were selected. MammaPrint test results were compared with clinical-pathological risk assessment using Adjuvant!Online.Results: Of 204 women aged 65 years or older (median age 70 years), 129 (63.2%) were classified as genomic low risk and 75 (36.8%) as genomic high risk. After a median follow-up of 8.6 years (range 0.3-17.9), the 5- and 10-year breast cancer specific survival (BCSS) for the genomic low risk group was 96% (SE 2%) and 86% (SE 4%) versus 82% (SE 4%) and 66% (SE 6%) for the genomic high risk group (log-rank p=0.001). In univariate analysis, MammaPrint was prognostic for 5-year BCSS (HR=5.0, 95%CI 1.8-14.1, p=0.002) and 10-year BCSS (HR=3.1, 95%CI 1.6-6.0, p=0.001). In a multivariate model adjusted for 10-year risk predicted by Adjuvant!Online, MammaPrint was independently prognostic for 5-year BCSS (HR=4.4, 95%CI 1.6-12.7, p=0.005) and 10-year BCSS (HR=2.5, 95%CI 1.3-5.0, p=0.009). As in prior validation series, the performance of MammaPrint was time dependent, with improved prognostication for early BCSS (≤5 years).Conclusion: Although a smaller proportion of breast cancers diagnosed in women 65 years or older are classified as high-risk by MammaPrint, it is an independent prognostic indicator that may be useful to select patients that can safely forego adjuvant chemotherapy. Additional data from patients over 70 years of age will be available at the time of the meeting. If these data are confirmatory, the ongoing prospective MINDACT trial will be amended to include older women.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4049.

Integrated Genomic Profiling of Endocrine Therapy Response in Advanced Breast Cancer

PurposeIn hormone receptor positive breast cancer the response rates for endocrine treatment, i.e. tamoxifen (TAM) or aromatase inhibitors (AIs), are only 50 to 70% in the advanced disease setting. The overall aim of this retrospective study is to identify a molecular signature using integrated genomic profiling to improve prediction of endocrine treatment outcome in the advanced disease setting.ObjectivesA) To compare mRNA expression profiles of TAM- and AI-treated patients and to identify genes and pathways associated with treatment outcome.B) To discover miRNA and mRNA signatures predictive for AI response.Patients and MethodsFresh frozen Estrogen Receptor (ER)-positive primary breast cancer specimens from patients with advanced disease treated with first-line AIs (N=55) or TAM (N=109) were analyzed. Expression profiles of 670 miRNAs and 44K mRNAs were generated using multiplex qRT-PCR and microarrays. Profiles were related to clinical response and time to progression (TTP). Statistical and bio-informatic tools were applied to discover and combine markers into an integrated genomic predictive signature. The nearest centroid prediction method of BRB-ArrayTools (Version3.7.0) was used to assess the predictive value.ResultsThe quality controlled and informative expression profiles of 277 miRNAs and 14112 mRNAs in 50 AI-treated tumors and 10433 mRNAs in 101 TAM-treated tumors were included for further analysis in the discovery phase.Global testing of mRNAs linked to Biocarta pathways demonstrated the involvement of the interferon pathway in endocrine therapy response in both AI- and TAM-treated patients. Using BRB-ArrayTools survival analysis to find genes associated with TTP (P<0.05), we identified 1002 mRNAs in AI-treated and 662 mRNAs in TAM-treated tumors to be significantly related with TTP.The overlap of 40 mRNAs between AI- and TAM-treatment was defined as a mRNA signature for endocrine treatment outcome. In TAM-treated patients this classifier has a 69% accuracy (63% sensitivity, 74% specificity), an odds ratio for clinical benefit of 4.69 (95% CI 1.99-11.05, P<0.001) and a hazard ratio for TTP of 0.17 (95% CI 0.10-0.29, P<0.001). In AI-treated patients, this 40mRNA signature has a performance of 78% accuracy (84% sensitivity, 62% specificity) and significantly predicts clinical benefit (odds ratio = 8.27, 95% CI 2.00-34.3, P=0.004) and TTP (hazard ratio = 0.07, 95% CI 0.02-0.22, P<0.001).After statistical analysis a 16 miRNAs classifier for AI-treatment outcome was identified with a performance of 78% accuracy (89% sensitivity, 46% specificity). This classifier significantly predicts clinical benefit (Odds ratio = 7.07, 95% CI 1.57-31.9, P=0.011) and TTP (hazard ratio = 0.24, 95% CI 0.09-0.61, P=0.003).The genomic mRNA and miRNA signatures are currently integrated and validated in additional samples as well as “in silico” on tumors treated with neo-adjuvant AI (Miller et al, JCO 2009).ConclusionThis is the first study that combines miRNA and mRNA profiling in an attempt to define an integrated genomic signature for endocrine treatment outcome. Additional prospective multicenter studies are needed to confirm the predictive value of this signature.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3029.

Microarray-based determination of ER, PR and HER2 receptor status: validation and comparison with IHC assessments

Abstract #3007

Background
 In breast cancer patients the level of expression of estrogen receptor (ER), progesterone receptor (PR) and HER2 is predictive for prognosis and/or treatment response. However, differences in assessment methods and interpretation can substantially affect the accuracy and reproducibility of the results. Previously, we have determined the association between immunohistochemistry (IHC) and mRNA levels for ER, PR and HER2, and have confirmed the accuracy of microarray readout on >400 samples. In the current study we describe the use of this microarray based readout on prospectively collected samples. We compared these readouts with multiple IHC and fluorescent in situ hybridization (FISH) assessments generated in various hospitals and a CLIA-certified reference laboratory and developed a microarray based test called TargetPrint™.
 Methods
 Gene expression data for ER, PR and HER2 were obtained by analysis of 100 breast carcinomas that have been collected prospectively within the RASTER study. Samples were stratified as receptor positive or negative using thresholds for ER, PR and HER2 mRNA levels. IHC assessment was performed (1) according to local standards of the hospital from where the sample originated, (2) by the central laboratory of the Netherlands Cancer Institute, and (3) at an independent reference laboratory using FDA-approved procedures and ASCO/CAP guidelines. A tumor was classified positive for ER and PR when ≥10% of tumor cells showed positive staining. HER2 IHC status was scored as 0, 1+, 2+ or 3+; a score of 3+ was considered positive. In case of 2+ samples, a FISH was performed to assess final HER2 amplification status. The cohort used in this study was pre-selected to include about two-third ER and PR positive samples and one-third HER2 positive samples.
 Results
 Multiple microarray readouts were highly reproducible (Pearson correlation 0.991) and resulted in 67, 61 and 39 percent positive samples for ER, PR and HER2, respectively. Comparison of microarray results with IHC (including FISH for HER2) performed at the three centers indicated highly similar results for receptor readout with a concordance of 92, 93 and 92% for ER; 84, 81 and 86% for PR; and 93, 95 and 94% for HER2. Overall misclassification rates between microarray and IHC readout were low for ER (0.08) and HER2 (0.06) and quite low for PR (0.14), and were comparable to the misclassification rates between the three IHC methods.
 Conclusion
 A microarray-based assessment of ER, PR and HER2 in relation to mRNA levels gives results comparable to multiple IHC methods and FISH and provides an objective and more quantitative assessment of tumor receptor status than IHC alone. Using TargetPrint™ for microarray readouts for hormone and HER2 receptor in addition to standard IHC will improve molecular characterization of breast cancer tissue.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3007.

Differential pattern of beta-amyloid, amyloid precursor protein and apolipoprotein E expression in cortical senile plaques

Regional differences in senile plaques immunostained by antibodies against beta-amyloid A4 (beta-A4), amyloid precursor protein 695 (APP) and apolipoprotein E (apo E) were studied in the hippocampus and the entorhinal, temporal and occipital cortices both quantitatively and semiquantitatively with respect to the laminar cortical distribution of the plaques. These patterns were related to the staging of Alzheimer's disease in regard to the distribution of neurofibrillary tangles (Braak and Braak (1991) Acta Neuropathol 82: 239-259). In the hippocampus and especially in sector CA 1, no significant differences in the number of plaques visualized by the different antibodies were found. In contrast, there was a striking difference in neocortical regions. Here, significantly higher numbers of plaques positive for beta-A4 than that for APP and apo E were present in all stages, except in the stages I and VI, and for apo E in stage II. The highest densities of beta-A4-positive plaques were found in the isocortical layers III and V and in the entorhinal pre-alpha, pre-gamma, pri-alpha and pri-beta layers. The preferentially affected area, showing plaques positive for all three antibodies, was the entorhinal-hippocampal circuit with early affection of CA 1, which represents the direct and indirect target of the entorhinal neurons of the upper layers. Therefore, we suggest that plaques with dystrophic neurites, positive for APP, seem to be generated secondarily in afferent areas such as the hippocampus, which is the main afferent target of the entorhinal region. Diffuse plaques, negative for APP and apo E, are virtually absent in the CA 1 and seem to originate independently of afferent neuronal dysfunction, as indicated by neurofibrillary tangles.

Representation of rearranged VH gene segments in the human adult antibody repertoire

The heavy chain variable region composition of the human adult Ab repertoire is poorly defined, but recent evidence suggests that peripheral blood B cells may express a nonstochastic assortment of VH genes. In this study, the contribution of individual VH gene segments to the human Ab repertoire has been assessed. As a measure of VH gene utilization, the frequency of occurrence of eight individual VH3 gene segments contained in rearrangements was assessed in the peripheral blood B cells of two adult subjects. In addition, the frequency of occurrence of rearrangements containing nine individual VH4 gene segments was analyzed in one of the subjects. More than 2500 independent rearrangements were analyzed. For controls, amplifications and subsequent identification of nonrearranged VH3 and VH4 genes from the same individuals were also performed. The results of this germ-line analysis indicated that approximately 25 VH3 gene segments and nine VH4 gene segments could be amplified quantitatively. However, usage of elements was not uniform; one VH3 element, V3-23, and one VH4 element, V4-34, were represented among rearrangements more frequently than were other members of their respective families. This pattern of VH utilization was apparent in B cells isolated from the same subject after an 8-mo interval, indicating the relative stability of the repertoire over time. These results indicate that the adult human Ab repertoire is dominated by a few VH genes demonstrating a pattern of nonrandom utilization that could involve preferential rearrangement and/or receptor-dependent selection.

Representation of rearranged VH gene segments in the human adult antibody repertoire

The heavy chain variable region composition of the human adult Ab repertoire is poorly defined, but recent evidence suggests that peripheral blood B cells may express a nonstochastic assortment of VH genes. In this study, the contribution of individual VH gene segments to the human Ab repertoire has been assessed. As a measure of VH gene utilization, the frequency of occurrence of eight individual VH3 gene segments contained in rearrangements was assessed in the peripheral blood B cells of two adult subjects. In addition, the frequency of occurrence of rearrangements containing nine individual VH4 gene segments was analyzed in one of the subjects. More than 2500 independent rearrangements were analyzed. For controls, amplifications and subsequent identification of nonrearranged VH3 and VH4 genes from the same individuals were also performed. The results of this germ-line analysis indicated that approximately 25 VH3 gene segments and nine VH4 gene segments could be amplified quantitatively. However, usage of elements was not uniform; one VH3 element, V3-23, and one VH4 element, V4-34, were represented among rearrangements more frequently than were other members of their respective families. This pattern of VH utilization was apparent in B cells isolated from the same subject after an 8-mo interval, indicating the relative stability of the repertoire over time. These results indicate that the adult human Ab repertoire is dominated by a few VH genes demonstrating a pattern of nonrandom utilization that could involve preferential rearrangement and/or receptor-dependent selection.