HER2 status in early breast cancer: relevance of cell staining patterns, gene amplification and polysomy 17

Clinicopathological Features of Breast Cancer with Polysomy 17 and Its Response to Neoadjuvant Chemotherapy

Objective

The interpretation of human epidermal growth factor receptor 2 (HER2) fluorescence in situ hybridization (FISH) results may be challenging in tumors with polysomy 17, which is defined as increased signals of chromosome enumeration probe 17 (CEP17). The effect of polysomy 17 on HER2 protein expression and tumor treatment response has not been established. In this retrospective study, we investigated the clinicopathological features of breast cancer with polysomy 17 and determined the tumors' response to neoadjuvant chemotherapy (NACT).

Materials and Methods

The study included 366 patients with primary breast cancer whose tumors had a CEP17 count of ≥ three/nucleus based on HER2 FISH studies. These cases were categorized according to HER2/CEP17 ratio and HER2 signals/nucleus using the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) guidelines. We compared the clinicopathological characteristics and tumor response to NACT among different groups.

Results

There was a statistically significant difference in patients' age at diagnosis, tumor pathological grade, estrogen and progesterone receptor status, and NACT response among different HER2 FISH groups. Polysomy 17 tumors in group 1 had a higher rate of response (pathological complete response and residual cancer burden class I) to NACT containing anti-HER2 reagent than did those in other groups (p = 0.004), whereas polysomy 17 tumors in group 3 did not show a significant response to anti-HER2 treatment.

Conclusion

Polysomy 17 tumors in different HER2 FISH groups have different pathological features and respond to NACT differently. These results may help us identify patients who will benefit from anti-HER2 therapy.

Heterogeneity analysis of PD-L1 expression and copy number status in EBUS-TBNA biopsy specimens of non-small cell lung cancer: Comparative assessment of primary and metastatic sites

OBJECTIVES

Most patients with non-small cell lung cancer (NSCLC) are diagnosed at advanced stages where small biopsy specimens obtained through endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) are sometimes the only available samples for diagnosis. We aimed to determine whether EBUS-TBNA specimens are suitable for the evaluation of PD-L1 protein expression and copy number alterations (CNAs).

MATERIALS AND METHODS

PD-L1 protein expression and CNAs in 71 EBUS-TBNA specimens of NSCLC were assessed. Sixty-eight corresponding transbronchial biopsy (TBB) specimens from primary sites, thirteen resected primary tumors, and six resected metastases were comparatively analyzed. PD-L1 expression in tumor cells was assessed by immunohistochemistry (E1L3N). Positivity of ≥1% was used as the cutoff. PD-L1 CNAs were assessed with fluorescent in situ hybridization and were classified into three categories: amplification, polysomy, and disomy. Concordance between EBUS-TBNA and other specimens was calculated.

RESULTS

The cohort comprised 48 men (67.6%), 15 never-smokers (21.1%), and 39 adenocarcinomas (54.9%). The concordance of PD-L1 positivity between EBUS-TBNA and other specimens was moderate; κ = 0.63 for EBUS-TBNA vs. TBB, κ = 0.68 for EBUS-TBNA vs. resected primary tumors, and κ = 1.0 for EBUS-TBNA vs. resected metastases. The concordance of PD-L1 CNA status was comparable with that of PD-L1 expression: κ = 0.60 for EBUS-TBNA vs. TBB and κ = 0.74 for EBUS-TBNA vs. resected primary tumors. When PD-L1 copy number was assessed as a continuous variable, the correlation of PD-L1 CNAs was superior to that of PD-L1 expression. Intratumorally, PD-L1 copy number was less heterogeneous than protein expression in whole sections of resected tumors.

CONCLUSION

EBUS-TBNA specimens can be used to assess PD-L1 CNAs and protein expression. Although spatial heterogeneity should be considered for accurate interpretation, the evaluation of PD-L1 CNAs provides more reproducible results than that of protein expression levels especially with regard to intratumoral heterogeneity.

Potential clinically useful prognostic biomarkers in triple-negative breast cancer: preliminary results of a retrospective analysis

Background

Triple-negative breast cancer (TNBC) has a poor prognosis, even in its early stages. In the absence of postoperative targeted treatments, intensive adjuvant chemotherapy regimens are proposed. For those favorable histologies, such as apocrine and adenoid cystic carcinoma, which frequently belong to TNBC, aggressive treatments are unnecessary.

Patients and methods

We retrospectively analyzed 631 cases of breast cancer, primary operated curatively, and followed up at our institution for at least 36 months to identify the bio-markers assessable by immunohistochemistry, to be proposed as prognostic score for tailoring adjuvant treatment to TNBC patients.

Results

The triple-negative phenotype was found in 85 patients (13.5%). Over a mean followup of 55.7 months, relapses occurred in 106 patients (16.8%), of which 18 (2.8%) were TNBC. Recurrence was directly correlated with Ki67 and cytokeratin 5/6 (CK5/6) immunoreactivity in all breast cancer patients (P=0.005), but only marginally with CK5/6 and epithelial cadherin (E-cad) expression in TNBC patients (P=0.07). Mean event-free survival (EFS) in TNBC patients was 85.52 months compared with 100.4 months in non-TNBC patients (P=0.228). The EFS of CK5/6-negative triple-negative patients was 68.84 months compared with 98.84 months in those who were CK5/6 positive (HR =5.08; P=0.038). EFS differed among patients identified as double-positive for E-cad and CK5/6 (83.87 months), those expressing E-cad or CK5/6 (64.23 months), and those negative for both biomarkers (39.64 months).

Conclusion

These preliminary results suggest that CK5/6 and E-cad are possible core biomarkers for a cost-effective prognostic evaluation of primary operable TNBC patients.

Distinct prognostic roles and heterogeneity of TTF1 copy number and TTF1 protein expression in non-small cell lung cancer

Thyroid transcription factor 1 (TTF1) located on chromosome band 14q13.3 is an oncogene and a suppressor gene in non-small cell lung cancer (NSCLC). The prognostic relevance of TTF1 copy number alterations (CNAs) and their association with TTF1 protein expression are poorly understood. Here, we assessed TTF1 CNAs and protein expression using microarrays in a cohort of 636 NSCLC, including 423 adenocarcinoma (ADC) and 171 squamous cell carcinoma (SCC). In addition, fluorescent in situ hybridization and immunohistochemistry were performed. TTF1 CNAs were detected in 23% of NSCLC (23% of ADC and 20% of SCC). Specifically, TTF1 amplification and polysomy were observed in 5% and 18% of NSCLC, and in 7% and 16% of ADC, respectively. TTF1 expression was detected in 85% of ADC. TTF1 CNAs were significantly associated with advanced tumor stage, EGFR mutations, and TTF1 expression. A multivariate Cox hazards model analysis of overall survival and recurrence-free survival demonstrated that both TTF1 amplification and polysomy were independent indicators of an unfavorable prognosis in patients with NSCLC. Survival was inversely correlated with TTF1 copy number. In contrast, TTF1 protein expression was an independent favorable prognostic factor. Intratumoral and intertumoral heterogeneities of TTF1 CNAs and TTF1 protein expression were assessed using primary cores from 138 pairs of primary tumors and corresponding nodal metastases. The concordance rate for TTF1 CNAs and TTF1 protein expression was high within tumors and between primary and metastatic tumors. Altogether, these results suggest that TTF1 CNAs are correlated with TTF1 protein expression, but have opposing effects on survival.

HER2/neu Testing In 432 Consecutive Breast Cancer Cases using FISH and IHC - A Comparative Study

INTRODUCTION

The development of trastuzumab, a HER-2/neu targeted monoclonal antibody resulted in significant improvements in clinical response and survival in HER-2/neu gene amplified group of patients. Thus, accurate assessment of HER-2/neu status becomes critical. Fluorescence In Situ Hybridization (FISH) and Immunohistochemistry (IHC) are the most commonly used methods for this purpose and specific recommendations exist with regard to the concordance to be observed between the two tests.

AIM

Here, we report and evaluate the concordance rate between FISH and IHC for HER-2/neu status in breast cancer specimens.

MATERIALS AND METHODS

Archival paraffin blocks of tumour tissue from 450 patients of breast cancer were analyzed for Her-2/neu status using FISH and IHC.

RESULTS

There was a highly significant concordance between the results of FISH and IHC assays in HER-2/neu status assessment in invasive breast cancer cases. There were inverse associations between the expression of Oestrogen Receptors/Progesterone Receptors (ER/PR) and HER-2/neu amplification.

CONCLUSION

Although, IHC gave significant concordant results with FISH in determining HER-2/neu status, its subjective grading system precludes its use as a gold standard. FISH should always be used to determine true gene amplification when the IHC results are equivocal.

Prognostic significance of equivocal human epidermal growth factor receptor 2 results and clinical utility of alternative chromosome 17 genes in patients with invasive breast cancer: A cohort study

BACKGROUND

The 2013 testing guidelines for determining the human epidermal growth factor receptor 2 (HER2) status include new cutoff points for the HER2/chromosome enumeration probe 17 (CEP17) ratio and the average HER2 copy number per cell, and they recommend using a reflex test with alternative chromosome 17 probes (Ch17Ps) to resolve equivocal HER2 results. This study sought to determine the clinical utility of alternative Ch17Ps in equivocal cases and the effects of equivocal results and/or a change in the HER2 status on patients' outcomes.

METHODS

The University of Texas MD Anderson Cancer Center database of HER2 dual-probe fluorescence in situ hybridization results from 2000 to 2010 was searched for cases of invasive breast cancer with HER2/CEP17 ratios < 2 and average HER2 copy numbers < 6 per cell. Cases with HER2 copy numbers of 4 to < 6 (the definition of equivocal HER2 results) were analyzed with alternative Ch17Ps for Smith-Magenis syndrome and retinoic acid receptor α genes. Disease-free survival (DFS) and overall survival (OS) were evaluated with respect to the HER2 copy number with multivariate Cox proportional hazards regression.

RESULTS

Among the 3630 patients meeting the inclusion criteria, 137 (4%) had equivocal HER2 results. With alternative Ch17Ps, 35 of 57 equivocal HER2 cases (61%) were upgraded to a positive HER2 status, and 22 cases (39%) remained unchanged. The 5-year DFS and OS adjusted hazard ratios (HRs) for copy numbers of 4 to < 6 versus < 4 were 0.6 (95% confidence interval [CI], 0.3-1.2) and 0.5 (95% CI, 0.2-1.0) with P values of .16 and .66, respectively. In comparison with HER2-negative cases, these CIs indicated that equivocal HER2 results were associated with either a protective effect (HR, < 0.5) or no effect (HR, 1.0).

CONCLUSIONS

These findings rule out a significant deleterious effect of equivocal HER2 results. Alternative Ch17Ps may erroneously upgrade the HER2 status; therefore, they cannot be considered reliable in clinical practice. Cancer 2017;123:1115-1123. © 2016 American Cancer Society.

HER2 intratumoral heterogeneity analyses by concurrent HER2 gene and protein assessment for the prognosis of HER2 negative invasive breast cancer patients

HER2 gene-protein assay (GPA) is a new method for the simultaneous evaluation of HER2 immunohistochemistry (IHC) and HER2 dual in situ hybridization (DISH) on single tissue sections of breast cancer. We investigated the presence of HER2 gene and protein discrepancy and HER2-heterogeneity using HER2-GPA. HER2 status was analyzed for the correlation between the presence of HER2-heterogeneity and patient prognosis. Consecutive 280 invasive breast cancer were examined. Statuses of HER2 protein and gene were evaluated in whole tumor sections of HER2 GPA slides. HER2 protein and gene combination patterns were classified to six phenotypic and genotypic types for each case, as well as at individual cell levels: (A) IHC and DISH positive; (B) IHC positive and DISH negative; (C) IHC equivocal and DISH positive; (D) IHC equivocal and DISH negative; (E) IHC negative and DISH positive; and (F) IHC and DISH negative. The presence of HER2-heterogeneity was determined by the existence of at least two of six types within one tumor. HER2-IHC positive patients had significantly worse survival than IHC negative patients and HER2-DISH positive patients had significantly worse survival than DISH negative patients. HER2 IHC negative and DISH positive patients had significantly worse recurrence-free survival than IHC and DISH negative patients. In the HER2 IHC and DISH negative group, the HER2 heterogeneous group had significantly worse survival than the nonheterogeneous group. Notably, among triple negative breast cancer (TNBC), the HER2 heterogeneous group had significantly worse survival than the nonheterogeneous group. Our study suggests that the presence of HER2-heterogeneity might be a prognostic factor in HER2 negative breast cancer patients, especially in TNBC.

The Clinicopathologic and Prognostic Value of Altered Chromosome 17 Centromere Copy Number in HER2 Fish Equivocal Breast Carcinomas

Chromosome 17 centromere (CEP17) gain is frequently observed in breast cancer by fluorescence in situ hybridization (FISH). To address the biologic characteristics and clinical significance of CEP17 gain in a large population of breast cancer patients, we performed FISH on a series of 770 breast cancer tissues to evaluate the status of human epidermal growth factor receptor 2 (HER2) gene and CEP17 by immunohistochemistry (IHC) and FISH. Among the 770 specimens, 184 cases showed CEP17 gain (23.9%). Histological grade, nodal status, HER2 by IHC, Ki 67 index, and p53 expression were significantly different between CEP17 gain tumors and HER2-positive tumors. In contrast with HER2-negative tumors, CEP17 gain tumors showed higher histological grade, higher HER2 score by IHC, and higher Ki 67 index. The patients with CEP17 gain tumors had an intermediate survival between HER2-negative and HER2-positive patients. By comparison to HER2-negative and HER2-positive patients, survival in luminal B patients with CEP17 gain tumors also fell in between. In conclusion, CEP17 gain tumors show specific differences compared with HER2-negative and HER2-positive tumors in clinical parameters and prognosis.

High-density SNP arrays improve detection of HER2 amplification and polyploidy in breast tumors

BACKGROUND

Human epidermal growth factor receptor-2 (HER2) overexpression and gene amplification are currently established by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), respectively. This study investigates whether high-density single nucleotide polymorphism (SNP) arrays can provide additional diagnostic power to assess HER2 gene status.

METHODS

DNA from 65 breast tumor samples previously diagnosed by HER2 IHC and FISH analysis were blinded and examined for HER2 copy number variation employing SNP array analysis.

RESULTS

SNP array analysis identified 24 (37%) samples with selective amplification or imbalance of the HER2 region in the q-arm of chromosome 17. In contrast, only 15 (23%) tumors were found to have HER2 amplification by IHC and FISH analysis. In total, there was a discrepancy in 19 (29%) samples between SNP array and IHC/FISH analysis. In 12 of these cases, the discrepancy towards FISH could be attributed to concomitant amplification or deletion of the centromeric region, which harbors the FISH reference probe sequence. In 3 tumors, repeated IHC/FISH analysis revealed that the original IHC/FISH analysis had failed to indicate the correct HER2 expression level. Finally, the SNP array analysis revealed that more than two thirds of the samples exhibited polyploidy that was unrecognized by conventional FISH.

CONCLUSIONS

Collectively, the data show that determination of HER2 copy number variations by SNP array-based genomic segmentation analysis is an effective supplement to IHC/FISH HER2 analysis that, by providing additional diagnostic sensitivity and accuracy, may elect more women for targeted treatment with HER2 inhibitors.

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.

HER2 in situ hybridization in breast cancer: clinical implications of polysomy 17 and genetic heterogeneity

Trastuzumab-containing therapy is a standard of care for patients with HER2+ breast cancer. HER2 status is routinely assigned using in situ hybridization to assess HER2 gene amplification, but interpretation of in situ hybridization results may be challenging in tumors with chromosome 17 polysomy or intratumoral genetic heterogeneity. Apparent chromosome 17 polysomy, defined by increased chromosome enumeration probe 17 (CEP17) signal number, is a common genetic aberration in breast cancer and represents an alternative mechanism for increasing HER2 copy number. Some studies have linked elevated CEP17 count ('polysomy') with adverse clinicopathologic features and HER2 overexpression, although there are numerous discrepancies in the literature. There is evidence that elevated CEP17 ('polysomy') count might account for trastuzumab response in tumors with normal HER2:CEP17 ratios. Nonetheless, recent studies establish that apparent 'polysomy' (CEP17 increase) is usually related to focal pericentromeric gains rather than true polysomy. Assigning HER2 status may also be complex where multiple cell subclones with distinct HER2 amplification characteristics coexist within the same tumor. Such genetic heterogeneity affects up to 40% of breast cancers when assessed according to a College of American Pathologists guideline, although other definitions have been proposed. Recent data have associated heterogeneity with unfavorable clinicopathologic variables and poor prognosis. Genetically heterogeneous tumors harboring HER2-amplified subclones have the potential to benefit from trastuzumab, but this has yet to be evaluated in clinical studies. In this review, we discuss the implications of apparent polysomy 17 and genetic heterogeneity for assigning HER2 status in clinical practice. Among our recommendations, we support the use of mean HER2 copy number rather than HER2:CEP17 ratio to define HER2 positivity in cases where coamplification of the centromere might mask HER2 amplification. We also highlight a need to harmonize in situ hybridization scoring methodology to support accurate HER2 status determination, particularly where there is evidence of heterogeneity.

HER2 in gastric cancer: Comparative analysis of three different antibodies using whole-tissue sections and tissue microarrays

AIM: To compare the performance of three commercially available anti-human epidermalgrowth factor receptor 2 (HER2) antibodies in whole-tissue sections and tissue microarrays (TMAs) of a series of gastric tumors.

METHODS: We present a comparative analysis of three anti-HER2 antibodies (HercepTest, 4B5 and SP3) using TMA and whole-tissue sections prepared from the same paraffin blocks of 199 gastric adenocarcinomas operated upon between January 2004 and December 2008 at a Brazilian cancer hospital. The data on the patients’ age, sex, the anatomical location of the tumor and the Lauren’s histological classification were collected from clinical and pathological records. The immunohistochemical (IHC) results were examined by two pathologists and the cases were classified as positive (3+), equivocal (2+) and negative (0 or 1+), according to the criteria of the IHC scoring system of gastric cancer. TMAs and whole-tissue sections were evaluated separately and independently. All cases yielding discordant IHC results and/or scored as 2+ were subjected to dual-color in situ hybridization in order to determine the final HER2 status. Besides determining the sensitivity and predictive value for HER2-positive status, we measured the accuracy of each antibody by calculating the area under the receiver operating characteristic (ROC) curve. The agreement between the results obtained using the TMAs and those obtained using the whole-tissue sections was assessed by means of Kappa coefficient.

RESULTS: Intratumoral heterogeneity of HER2 expression was observed with all antibodies. HER2-positive expression (3+) in the whole-tissue sections was observed in 23 cases (11.6%) using the 4B5 antibody, in 18 cases (9.1%) using the SP3 antibody and in 10 cases (5.1%) using the HercepTest antibody. In the TMAs, 11 positive cases (5.6%) were identified using SP3 antibody, 9 (4.6%) using the 4B5 antibody and 6 (3%) using the HercepTest antibody. The sensitivity using whole-tissue sections and TMA, respectively, was 95.2% and 42.9% with 4B5, 90.5% and 66.7% with SP3 and 47.6% and 42.9% with HercepTest. The accuracy, calculated from the area under the ROC curve, using whole-tissue sections and TMA, respectively, was 0.91 and 0.79 by 4B5, 0.86 and 0.80 by SP3 and 0.73 and 0.71 by HercepTest. The concordance of the results obtained using whole-tissue sections and TMA was 97.4% (Kappa 0.75) using HercepTest, 85.6% (Kappa 0.56) using SP3 and 84.1% (Kappa 0.38) using 4B5.

CONCLUSION: The use of the 4B5 antibody on whole-tissue sections was the most accurate IHC method for evaluating HER2 expression in gastric adenocarcinoma.

Chromosome 17 polysomy: correlation with histological parameters and HER2NEU gene amplification

Aims

HER2NEU gene amplification is present in the majority of invasive breast carcinomas that have HER2 protein overexpression. A subset of breast cancers harbour an increased chromosome 17 (CEP17) copy number (polysomy 17). We investigated the clinicopathologic significance of polysomy 17 in correlation with various histological parameters and HER2NEU gene amplification.

Methods

We collected the surgical specimens of 266 consecutive cases of primary invasive breast carcinomas. HER2NEU gene status and CEP17 copy numbers were assessed by fluorescent in situ hybridisation (FISH). Chromosome 17 polysomy was determined by the presence of ≥3 average CEP17 signals per nucleus.

Results

63 tumours (23.7%) harboured polysomy 17. Carcinomas with polysomy 17 were associated with adverse histological indicators including high histological grade, high nuclear grade, poor Nottingham Prognostic Index, advanced local tumour extent and progesterone receptor negativity. Polysomy 17 was common to HER2NEU amplified and unamplified tumours, and more frequently observed in HER2NEU unamplified (71.4%) cases.

Conclusions

In the absence of the gene amplification, HER2 protein overexpression may be explained by other mechanisms including polysomy 17.

Evaluation of the prognostic role of centromere 17 gain and HER2/topoisomerase II alpha gene status and protein expression in patients with breast cancer treated with anthracycline-containing adjuvant chemotherapy: pooled analysis of two Hellenic Cooperative Oncology Group (HeCOG) phase III trials

BACKGROUND

The HER2 gene has been established as a valid biological marker for the treatment of breast cancer patients with trastuzumab and probably other agents, such as paclitaxel and anthracyclines. The TOP2A gene has been associated with response to anthracyclines. Limited information exists on the relationship of HER2/TOP2A gene status in the presence of centromere 17 (CEP17) gain with outcome of patients treated with anthracycline-containing adjuvant chemotherapy.

METHODS

Formalin-fixed paraffin-embedded tumor tissue samples from 1031 patients with high-risk operable breast cancer, enrolled in two consecutive phase III trials, were assessed in a central laboratory by fluorescence in situ hybridization for HER2/TOP2A gene amplification and CEP17 gain (CEP17 probe). Amplification of HER2 and TOP2A were defined as a gene/CEP17 ratio of >2.2 and ≥2.0, respectively, or gene copy number higher than 6. Additionally, HER2, TopoIIa, ER/PgR and Ki67 protein expression was assessed by immunohistochemistry (IHC) and patients were classified according to their IHC phenotype. Treatment consisted of epirubicin-based adjuvant chemotherapy followed by hormonal therapy and radiation, as indicated.

RESULTS

HER2 amplification was found in 23.7% of the patients and TOP2A amplification in 10.1%. In total, 41.8% of HER2-amplified tumors demonstrated TOP2A co-amplification. The median (range) of HER2, TOP2A and CEP17 gain was 2.55 (0.70-45.15), 2.20 (0.70-26.15) and 2.00 (0.70-26.55), respectively. Forty percent of the tumors had CEP17 gain (51% of those with HER2 amplification). Adjusting for treatment groups in the Cox model, HER2 amplification, TOP2A amplification, CEP17 gain and HER2/TOP2A co-amplification were not associated with time to relapse or time to death.

CONCLUSION

HER2 amplification, TOP2A amplification, CEP17 gain and HER2/TOP2A co-amplification were not associated with outcome in high-risk breast cancer patients treated with anthracycline-based adjuvant chemotherapy.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12611000506998 and ACTRN12609001036202.

Is it necessary to evaluate nuclei in HER2 FISH evaluation?

A new method that simplifies the evaluation of the traditional HER2 fluorescence in situ hybridization (FISH) evaluation in breast cancer was proposed. HER2 status was evaluated in digital images (DIs) captured from 423 invasive breast cancer stained sections. All centromeric/CEP17 and HER2 gene signals obtained from separated stacked DIs were manually counted on the screen. The global ratios were compared with the traditional FISH evaluation and the immunohistochemical status. The 2 FISH scores were convergent in 96.93% of cases, showing an "almost perfect" agreement with a weighted k of 0.956 (95% confidence interval, 0.928-0.985). The new method evaluates at least 3 times more nuclei than traditional methods and also has an almost perfect agreement with the immunohistochemical scores. The proposed enhanced method substantially improves HER2 FISH assessment in breast cancer biopsy specimens because the evaluation of HER2/CEP17 copy numbers is more representative, easier, and faster than the conventional method.

Efficacy of combined therapy of goserelin and letrozole on very young women with advanced breast cancer as first-line endocrine therapy

Breast cancer in young women younger than 35 years old is rare, aggressive and associated with a poor prognosis. Endocrine therapy is a preferred treatment modality in hormone receptor-positive early stage and advanced breast cancer, combined therapy of goserelin and letrozole presents an option for premenopausal women. We reported the efficacy and safety of therapy of goserelin plus letrozole on very young women with advanced breast cancer as first-line endocrine therapy. Thirty-five patients with first diagnosed as advanced breast cancer, age younger than 35 years, were enrolled in the study. All patients received goserelin 3.6 mg by subcutaneous injection every 4 weeks along with letrozole 2.5mg daily by mouth as first-line endocrine therapy. The study endpoints were objective response rate (ORR), clinical benefit (CB), progression-free survival (PFS), overall survival (OS) and toxicity. The median duration of response to the therapy was 21 (range, 10-56) months, and median duration of follow-up was 44 (range, 5-79) months. The ORR was 25.7%, with one complete response (CR, 2.9%) and eight partial response (PR, 22.9%). Twenty-two patients had stable disease at 24 weeks, for a clinical benefit rate of 65.7%. The median PFS was 9.6 (range 5-58) months and median OS was 33 (range 6-72) months. During the therapy and follow-up, no serious toxicities were reported. Combined therapy of goserelin and letrozole appears to be an efficacious and well-tolerated therapy for very young women with advanced breast cancer. Further investigations involving more patients, combination of other therapies and longer follow-up are requisite.

HER2 expression in breast cancer with nonamplified HER2 and gains of chromosome 17 centromere

Gains of chromosome 17 centromere (CEP17) may be accompanied by gains of chromosome 17q. To evaluate the effect of CEP17 gains (CEP17>3 copies per tumor nucleus) on the expression of the HER2 gene, which is located on chromosome 17q12-21.32, we analyzed HER2 amplification and expression in breast carcinomas with and without CEP17 gains. We isolated tumor nuclei from frozen tissues of 37 breast carcinomas for analysis of the HER2 gene and CEP17 by fluorescence in situ hybridization. HER2 expression was detected by immunohistochemistry (IHC) performed on formalin-fixed, paraffin-embedded sections of the corresponding tumors. Tumors with amplified HER2 as determined by both HER2 copy number and HER2/CEP17 ratio were detected in 29.7% (11/37). CEP17 gains were significantly associated with HER2 amplification (P=0.005) but not associated with estrogen receptor status, tumor grade, and lymph node status (P>0.05). In contrast, HER2 amplification was significantly associated with estrogen receptor negativity (P=0.020) but not with tumor grade and lymph node status (P>0.05). IHC analysis was performed in 7 HER2-amplified tumors and all of these were IHC 3+, which were used as positive controls. Among HER2-non-amplified tumors with CEP17 gains, only 1 tumor (1/8, 12.5%) was IHC 3+. However, none of the HER2-non-amplified tumors without CEP17 gains was IHC 3+. In HER2-non-amplified tumors, there was no significant association between HER2 protein expression as detected by IHC and CEP17 or HER2 copy number (P=0.999, P=0.785, respectively). These findings indicate that in the absence of HER2 amplification, CEP17 gains do not have a significant effect on HER2 protein expression.

Centromere 17 Copy Number Alteration: Negative Prognostic Factor in Invasive Breast Cancer?

Context.—Chromosome 17 polysomy has been identified in 5% to 50% of invasive breast cancers; even though a relationship with human epidermal growth factor receptor 2 (HER2/neu) status has been reported, other studies have shown that coincident centromere 17 (Cep17) amplification may be the cause of an overestimation of chromosome 17 polysomy in fluorescence in situ hybridization (FISH) testing.

Objective.—To evaluate polysomy/amplification of Cep17 in invasive breast cancer with relation to proliferative activity (Ki-67), estrogen receptor, progesterone receptor, and HER2/neu status, in an attempt to identify a subgroup of patients with a worse prognosis.

Design.—A total of 647 cases of invasive ductal breast cancer were collected and subjected to FISH analysis for HER2/neu gene and centromere 17 alteration, HercepTest for HER2/neu protein expression, and routine immunohistochemistry for Ki-67 and hormone receptor status.

Results.—Copy number gain of Cep17 was observed in 27.3% of cases. Within this group, HER2/neu gene amplification was detected in 14.1% of cases, whereas HER2/neu expression was scored 3+ in 20.1% of cases; about half of the HER2/neu overexpressing cases (9.8%) did not show amplification by FISH. Moreover, 69% of polysomic cases showed high Ki-67 index.

Conclusions.—(1) Centromere 17–altered cases are frequently HER2/neu overexpressing but not amplified, resulting in HercepTest/FISH disagreement; (2) HER2/neu amplification is seen at a higher incidence in cases without Cep17 copy number alterations, which are therefore not necessarily due to chromosome 17 disorder; (3) proliferation index is significantly higher in aneusomic tumors. These data suggest that the presence of Cep17 alterations could identify a subset of breast cancers with more aggressive biological and clinical behavior, which may show nonresponsiveness to conventional therapy independently of HER2/neu amplification status.

Efficacy of primed in situ labelling in determination of HER-2 gene amplification and CEN-17 status in breast cancer tissue

Considerable attention has been given to the accuracy of HER-2 testing and the correlation between the results of different testing methods. This interest reflects the growing importance of HER-2 status in the management of patients with breast cancer. In this study the detection of HER-2 gene and centromere 17 status was evaluated using dual-colour primed in situ labelling (PRINS) in comparison with fluorescence in situ hybridization (FISH). These two methods were evaluated on a series of 27 formalin fixed paraffin embedded breast carcinoma tumours, previously tested for protein overexpression by HercepTest (grouped into Hercep 1+/0, 2+ and 3+). HER-2 gene amplification (ratio ≥ 2.2) by PRINS was found in 3:3, 6:21 and 0:3 in IHC 3+, 2+ and 1+/0 cases, respectively. Comparing FISH and IHC (immunohistochemistry), showed the same results as for PRINS and IHC. Chromosome 17 aneusomy was found in 10 of 21 IHC 2+ cases (47.6%), of which 1 (10%) showed hypodisomy (chromosome 17 copy number per cell ≤ 1.75), 7 (70%) showed low polysomy (chromosome 17 copy number per cell=2.26 - 3.75) and 2 (20%) showed high polysomy (chromosome 17 copy number per cell ≥ 3.76). The overall concordance of detection of HER-2 gene amplification by FISH and PRINS was 100% (27:27). Furthermore, both the level of HER-2 amplification and copy number of CEN17 analysis results correlated well between the two methods. In conclusion, PRINS is a reliable, reproducible technique and in our opinion can be used as an additional test to determine HER-2 status in breast tumours.

Prognostic value of TOP2A gene amplification and chromosome 17 polysomy in early breast cancer

The aim of this study was to analyze the occurrence of TOP2A gene amplification and chromosome 17 polysomy in patients with early breast cancer and to correlate the status of these alterations with the prognostic significance expressed as patients' clinical features and survival. Such concurrent analyses of TOP2A gene status and chromosome 17 polysomy have not been performed before. Study group included 149 consecutive stage I-III patients administered standard multimodality treatment. TOP2A abnormalities were examined by standard fluorescence in situ hybridization (FISH) and developed by our group quantitative real-time PCR (qPCR). TOP2A amplification and deletion assessed by FISH were found in 23% and 7% of the tumours, respectively, and by qPCR in 31% and 11% of the tumours, respectively. Chromosome 17 polysomy was detected in 40% of the cases. TOP2A amplification (by qPCR) correlated with shorter disease-free survival (p = 0.03) and overall survival (p = 0.047), and the prognostic value of TOP2A was confirmed in the multivariate analysis (HR = 3.22, 95% CI 1.09-9.56, p = 0.03). TOP2A gene amplification, but not chromosome 17 polysomy, carries negative prognostic information in early breast cancer. Given the aforementioned results, qPCR might serve as a prognostic tool in determining the patient's prognosis.

Update on HER2 testing for breast and upper gastrointestinal tract cancers

With the regulatory approvals in Europe and the USA of trastuzumab-based anti-HER2 targeted therapy for upper gastrointestinal cancers in 2010, HER2 testing has now become universal for newly diagnosed cases of both breast cancer and adenocarcinomas of esophagus, stomach and gastroesophageal origin. In the 12 years or more since the approval of trastuzumab for breast cancer, general refinements in approaches to HER2 testing, including a greater understanding of the implications of preanalytic factors impacting the test results and the application of standardization of reporting of HER2 test results, have taken place. There has also been continuing development in breast cancer with the introduction of new HER2 tests, including non-FISH tests, dimerization assays, phosphorylated HER2 receptor tests, mRNA-based tests, HER2 gene sequencing tests and the application of HER2 testing to circulating tumor cells. Most recently, the introduction of HER2 testing for upper gastrointentinal malignancies has emphasized the need for performing and interpreting slide-based assays in a manner unique to these specimens and not to apply the breast cancer testing protocols to esophageal and gastric adenocarcinomas.

HER2 gene amplification in patients with breast cancer with equivocal IHC results

Aims

Equivocal human epidermal growth factor receptor 2 protein (HER2) (2+) immunohistochemistry (IHC) is subject to significant interobserver variation and poses a challenge in obtaining a definitive positive or negative test result. This equivocal test result group accounts for approximately 15% of all tumours, and for optimal guidance of HER2 targeted therapy, a further analysis of quantification of gene copy number and amplification status is needed for patients with early or metastatic breast cancer.

Methods

553 breast-cancer specimens with equivocal HER2 IHC(2+) test results were collected and subsequently centrally retested by chromogenic in situ hybridisation (CISH), and HER2 gene copy numbers per tumour cell nucleus were determined.

Results

Using CISH, 77 of 553 equivocal HER2 IHC(2+) test result cases (13.9% of total) showed high levels of HER2 gene amplification (≥10.0 gene copies per nucleus), and 41 of 553 (7.4% of total) showed low-level HER2 gene amplification (6.0–9.9 gene copies per nucleus). In 73.6% of cases, no amplification of the HER2 gene was shown, and in only 4.9% of cases was an equivocal test result by CISH observed (4.0–5.9 gene copies per nucleus).

Conclusions

Testing by CISH of all equivocal HER2 IHC(2+) test result provides a definitive guidance in HER2 targeted therapy in 95.1% of cases. A significant proportion (21.3%) of patients with equivocal IHC(2+) test results show amplification of the HER2 gene.

Breast carcinomas with borderline (2+) HER2 immunohistochemistry: percentage of cells with complete membrane staining for HER2 and the frequency of HER2 amplification

AIM

HER2 status is vital for selecting breast cancer patients for trastuzumab treatment. One recommended approach is to assess immunohistochemical staining and then perform in situ hybridisation on those tumours with a borderline (2+) immunohistochemical result. This audit aimed to assess the value of the percentage of immunohistochemical staining in 2+ tumours in selecting tumours for in-situ hybridisation.

METHODS

HER2 immunohistochemistry and in situ hybridisation was performed according to UK guidelines. The percentage of complete membrane staining of invasive carcinoma cells for HER2 was recorded as part of routine reporting.

RESULTS

191 (11%) of 1735 invasive carcinomas were scored as 3+. 419 (24%) were scored as 2+. 57 of 413 2+ carcinomas (14%) were amplified (ratio of HER2 to chromosome 17 ≥ 2.0). The frequency of amplification was related to the percentage of complete membrane staining: eight of 149 (5%) with 10-19% membrane staining, 11 of 93 (12%) with 20-29% staining, 26 of 150 (17%) with 30-79% staining and 12 of 21 (57%) with 80-100% staining.

CONCLUSIONS

This audit suggests that increasing the threshold for 2+ from 10% to 20% complete membrane staining would reduce the number of in-situ hybridisation tests by 36%, but reduce the detection of amplified tumours by 14%.

Prospective multi-centre study to validate chromogenic in situ hybridisation for the assessment of HER2 gene amplification in specimens from adjuvant and metastatic breast cancer patients

PURPOSE

As HER2 status is a strong predictor of the response to trastuzumab, clinical guidelines recommend that all breast tumours are first evaluated for HER2 protein expression by immunohistochemistry (IHC) followed by confirmatory testing for HER2 gene amplification using fluorescence in situ hybridisation (FISH) for 2+ cases. Alternatively, chromogenic in situ hybridisation (CISH) offers a simpler, less expensive approach to detect HER2 amplification.

METHODS

In this prospective, multi-centre study, based on the largest dataset for HER2 testing in Germany to date, we evaluated the concordance between FISH and CISH in 399 samples from adjuvant and metastatic breast cancer patients. Tumour specimens from routine diagnostic practice were analysed by IHC, FISH and CISH in four reference centres.

RESULTS

FISH and CISH results were strongly concordant (κ = 0.83), with 95% of cases showing agreement. Despite variable IHC scoring across testing centres, complete consensus among the three methods was observed for 246 cases, representing 91% of all IHC positive (3+) or negative (0/1+) cases. Confirmatory testing of 132 IHC equivocal (2+) cases also yielded highly concordant results between FISH and CISH.

CONCLUSIONS

These data validate CISH for the assessment of HER2 gene amplification in breast tumours and, confirm CISH as a valid alternative to FISH in HER2 testing.

Testing for HER2 in Breast Cancer: A Continuing Evolution

Human epidermal growth factor receptor 2 (HER2) is an important prognostic and predictive factor in breast cancer. HER2 is overexpressed in approximately 15%–20% of invasive breast carcinomas and is associated with earlier recurrence, shortened disease free survival, and poor prognosis. Trastuzumab (Herceptin) a “humanized” monoclonal antibody targets the extracellular domain of HER2 and is widely used in the management of HER2 positive breast cancers. Accurate assessment of HER2 is thus critical in the management of breast cancer. The aim of this paper is to present a comprehensive review of HER2 with reference to its discovery and biology, clinical significance, prognostic value, targeted therapy, current and new testing modalities, and the interpretation guidelines and pitfalls.

Triple negativity and young age as prognostic factors in lymph node-negative invasive ductal carcinoma of 1 cm or less

BACKGROUND

Whether a systemic adjuvant treatment is needed is an area of controversy in patients with node-negative early breast cancer with tumor size of ≤1 cm, including T1mic.

METHODS

We performed a retrospective analysis of clinical and pathology data of all consecutive patients with node-negative T1mic, T1a, and T1b invasive ductal carcinoma who received surgery between Jan 2000 and Dec 2006. The recurrence free survival (RFS) and risk factors for recurrence were identified.

RESULTS

Out of 3889 patients diagnosed with breast cancer, 375 patients were enrolled (T1mic:120, T1a:93, T1b:162). Median age at diagnosis was 49. After a median follow up of 60.8 months, 12 patients developed recurrences (T1mic:4 (3.3%), T1a:2 (2.2%), T1b:6 (3.7%)), with a five-year cumulative RFS rate of 97.2%. Distant recurrence was identified in three patients. Age younger than 35 years (HR 4.91; 95% CI 1.014-23.763, p = 0.048) and triple negative disease (HR 4.93; 95% CI 1.312-18.519, p = 0.018) were significantly associated with a higher rate of recurrence. HER2 overexpression, Ki-67, and p53 status did not affect RFS.

CONCLUSIONS

Prognosis of node-negative breast cancer with T1mic, T1a and T1b is excellent, but patients under 35 years of age or with triple negative disease have a relatively high risk of recurrence.

Human epidermal growth factor receptor 2 assessment in a case-control study: comparison of fluorescence in situ hybridization and quantitative reverse transcription polymerase chain reaction performed by central laboratories

PURPOSE

The optimal method to assess human epidermal growth factor receptor 2 (HER2) status remains highly controversial. Before reporting patient HER2 results, American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines mandate that laboratories demonstrate ≥ 95% concordance to another approved laboratory or methodology. Here, we compare central laboratory HER2 assessed by fluorescence in situ hybridization (FISH) and quantitative reverse transcriptase polymerase chain reaction (RT-PCR) using Oncotype DX in lymph node-negative, chemotherapy-untreated patients from a large Kaiser Permanente case-control study.

PATIENTS AND METHODS

Breast cancer specimens from the Kaiser-Genomic Health study were examined. Central FISH assessment of HER2 amplification and polysomy 17 was conducted by PhenoPath Laboratories (ratios > 2.2, 1.8 to 2.2, and < 1.8 define HER2 positive, HER2 equivocal, and HER2 negative, respectively). HER2 expression by RT-PCR was conducted using Oncotype DX by Genomic Health (normalized expression units ≥ 11.5, 10.7 to < 11.5, and < 10.7 define HER2 positive, HER2 equivocal, and HER2 negative, respectively). Concordance analyses followed ASCO/CAP guidelines.

RESULTS

HER2 concordance by central FISH and central RT-PCR was 97% (95% CI, 96% to 99%). Twelve percent (67 of 568 patients) and 11% (60 of 568 patients) of patients were HER2 positive by RT-PCR and FISH, respectively. HER2-positive patients had increased odds of dying from breast cancer compared with HER2-negative patients. Polysomy 17 was demonstrated in 12.5% of all patients and 33% of FISH-positive patients. Nineteen of 20 FISH-positive patients with polysomy 17 were also RT-PCR HER2 positive. Although not statistically significantly different, HER2-positive/polysomy 17 patients tended to have the worst prognosis, followed by HER2-positive/eusomic, HER2-negative/polysomy 17, and HER2-negative/eusomic patients.

CONCLUSION

There is a high degree of concordance between central FISH and quantitative RT-PCR using Oncotype DX for HER2 status, and the assay warrants additional study in a trastuzumab-treated population.

Evaluation of HER2 in breast cancer: reality and expectations

BACKGROUND

The introduction of drugs, whose mechanisms of action are directed against specific molecules involved in cancer initiation and/or progression, has changed the daily workup of breast cancer patients. At present, HER2 expression and/or amplification should be evaluated in every primary invasive breast cancer either at the time of diagnosis or at the time of recurrence, mostly to guide selection of trastuzumab in the adjuvant and/or metastatic setting. The adequate selection of patients is an essential step for indication of anti-HER2 therapy.

OBJECTIVE

This review focuses on the state of the art for HER2 evaluation in breast cancer, as well as expectations regarding future molecular assays based on mechanisms of resistance to HER2-driven therapy.

METHODS

Data were obtained by searching the PubMed database, including the terms 'HER2', 'in situ hybridisation', 'immunohistochemistry', 'trastuzumab', 'breast cancer', 'therapy', 'resistance' and 'tyrosine-kinase inhibitors', with a preference for updated publications.

CONCLUSION

Pathologists have a central role in the selection of patients who will benefit from anti-HER-based therapies, with a responsibility to obtain the most reliable results for immunohistochemistry and in situ hybridisation techniques. Pre-analytical variables, such as type of fixative and time of fixation, are critical to guarantee consistent and quality assays, as well as to facilitate interpretation and decrease interobserver variability. Rigorous quality control and centralisation of techniques/interpretation of results are recommended to guarantee consistent assays.

HER-2 protein overexpressing breast cancer without gene amplification shows higher hormone receptor expression than HER-2 protein overexpressing breast cancer with gene amplification

Cases of breast cancer showing human epidermal growth factor receptor-2 (HER-2) protein overexpression without corresponding gene amplification have been found in immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH) results. We investigated the clinicopathological characteristics of cases showing HER-2 protein overexpression breast cancer without gene amplification (IHC3+/FISH-) and compared them to cases showing HER-2 protein overexpression breast cancer with gene amplification (IHC3+/FISH+). This study was conducted on 90 patients with HER-2 IHC3+ breast cancer. The clinicopathological factors analyzed included tumor size, histological grade, nuclear grade, nodal involvement, and hormone receptor status. HER-2 IHC3+/FISH- breast cancer was found in 14 of 84 tumors (16.7%) and showed a statistically significant lower histological and nuclear grade (P = .000) and higher expression of estrogen receptors (ERs) and progesterone receptors (PRs) (P = .006) than IHC3+/FISH+ breast cancer. In conclusion, HER-2 IHC3+/FISH- breast cancer could be a subgroup showing lower histological/nuclear grade and higher expression of ERs/PRs.

Poor prognostic significance of unamplified chromosome 17 polysomy in invasive breast carcinoma

The human epidermal growth factor receptor 2 (HER2) oncoprotein is overexpressed in about 20% of breast cancers, with HER2 gene amplification responsible for protein overexpression in the vast majority of patients. A subset of breast cancers have chromosome 17 aneusomy, due to either 17 monosomy (a single copy of chromosome 17) or polysomy (increased copy numbers of chromosome 17). Although HER2 overexpression is an established adverse prognostic factor in breast cancer, the role of unamplified chromosome 17 polysomy is uncertain and there is a paucity of literature on the correlation of chromosome 17 aneusomy with important prognostic and predictive pathologic factors in invasive breast carcinoma. Furthermore, while patients showing HER2 amplification with or without polysomy 17 are treated with trastuzumab with or without other chemotherapy, treatment of patients with unamplified chromosome 17 polysomy is not well defined. Currently most of these patients are treated similar to patients with neither amplification nor 17 polysomy. The aim of this study was to compare some prognostic and predictive factors in invasive breast carcinoma in patients with unamplified chromosome 17 polysomy with that seen in cases with HER2 gene amplification and those with neither amplification or polysomy. We found that invasive breast carcinomas with unamplified chromosome 17 polysomy are associated with several adverse prognostic indicators such as a higher nuclear grade, mitotic activity, Nottingham score, histologic grade, tumor stage, and greater estrogen receptor negativity with a trend towards the amplified group, in contrast to patients with neither amplification or polysomy. Although most patients with unamplified 17 polysomy have a 2+ equivocal score on immunohistochemistry, a minority has a 3+ positive score. An increased adverse role for unamplified polysomy along with 3+ protein expression in some patients supports the idea that these patients should be considered for therapy with trastuzumab and/or anthracyclines.

Genotypic intratumoral heterogeneity in breast carcinoma with HER2/neu amplification: evaluation according to ASCO/CAP criteria

We evaluated intratumoral heterogeneity of 30 ductal breast carcinomas with HER2/neu amplification, scored by the American Society of Clinical Oncology/ College of American Pathologists (ASCO/CAP) criteria, and 3+ immunoexpression. High-grade (ratio > or =4.0) vs low-grade amplification (ratio >2.2 to <4.0) and chromosome 17 polysomy were also evaluated. On whole tissue sections, 20 tumors (67%) showed high-grade and 10 (33%) showed low-grade HER2/ neu amplification. Of 20 tumors with high-grade amplification, 14 (70%) showed no intratumoral genotypic heterogeneity; 6 (30%) showed at least 1 core with low-grade amplification. Of 10 cases with low-grade amplification, 6 (60%) showed no intratumoral heterogeneity; 4 (40%) showed chromosome 17 polysomy without gene amplification in 2 of 3 cores per case. Of 30 cases with gene amplification, 4 (13%) showed a "not-amplified pattern" in other parts of the tumor. The routine assessment of HER2/neu amplification using the ASCO/CAP criteria on whole tissue sections is not significantly confounded by intratumoral heterogeneity in breast cancer with high-grade amplification; however, genetic heterogeneity exists in a subset of breast carcinomas with low-grade amplification. The clinical relevance and impact on treatment outcome of intratumoral heterogeneity in breast cancer with low-grade HER2/neu amplification or chromosome 17 polysomy need further investigation.

The HER-2 receptor and breast cancer: ten years of targeted anti-HER-2 therapy and personalized medicine

The human epidermal growth factor receptor (HER-2) oncogene encodes a transmembrane tyrosine kinase receptor that has evolved as a major classifier of invasive breast cancer and target of therapy for the disease. The validation of the general prognostic significance of HER-2 gene amplification and protein overexpression in the absence of anti-HER-2 targeted therapy is discussed in a study of 107 published studies involving 39,730 patients, which produced an overall HER-2-positive rate of 22.2% and a mean relative risk for overall survival (OS) of 2.74. The issue of HER-2 status in primary versus metastatic breast cancer is considered along with a section on the features of metastatic HER-2-positive disease. The major marketed slide-based HER-2 testing approaches, immunohistochemistry, fluorescence in situ hybridization, and chromogenic in situ hybridization, are presented and contrasted in detail against the background of the published American Society of Clinical Oncology-College of American Pathologists guidelines for HER-2 testing. Testing issues, such as the impact of chromosome 17 polysomy and local versus central HER-2 testing, are also discussed. Emerging novel HER-2 testing techniques, including mRNA-based testing by real-time polymerase chain reaction and DNA microarray methods, HER-2 receptor dimerization, phosphorylated HER-2 receptors, and HER-2 status in circulating tumor cells, are also considered. A series of biomarkers potentially associated with resistance to trastuzumab is discussed with emphasis on the phosphatase and tensin homologue deleted on chromosome ten/Akt and insulin-like growth factor receptor pathways. The efficacy results for the more recently approved small molecule HER-1/HER-2 kinase inhibitor lapatinib are also presented along with a more limited review of markers of resistance for this agent. Additional topics in this section include combinations of both anti-HER-2 targeted therapies together as well as with novel agents including bevacizumab, everolimus, and tenespimycin. A series of novel HER-2-targeting agents is also presented, including pertuzumab, ertumaxomab, HER-2 vaccines, and recently discovered tyrosine kinase inhibitors. Biomarkers predictive of HER-2 targeted therapy toxicity are included, and the review concludes with a consideration of HER-2 status in the prediction of response to non-HER-2 targeted treatments including hormonal therapy, anthracyclines, and taxanes.

Breast cancer and aneusomy 17: implications for carcinogenesis and therapeutic response

Abnormalities of chromosome 17, recognised over two decades ago to be important in tumorigenesis, often occur in breast cancer. Changes of specific loci on chromosome 17 including ERBB2 amplification, P53 loss, BRCA1 loss, and TOP2A amplification or deletion are known to have important roles in breast-cancer pathophysiology. Numerical aberrations of chromosome 17 are linked to breast-cancer initiation and progression, and possibly to treatment response. However, the clinical importance of chromosome 17 anomalies, in particular the effect on ERBB2 protein expression, is unknown. Reports are conflicting regarding the association of copy gain of chromosome 17 (polysomy 17) with strong ERBB2 protein expression in the absence of true ERBB2 gene amplification. Copy-number anomalies in chromosome 17 seem to be common in tumours that show discrepant ERBB2 expression and in tumours with discordant ERBB2-protein and ERBB2 gene copy number measurements. The mechanisms of ERBB2 dosage changes-gene amplification versus chromosome gain and loss-probably differ in primary and metastatic disease; however, a correction for chromosome 17 copy-number is necessary to completely distinguish between these mechanisms. A better understanding of how polysomy 17 affects gene-copy number and protein expression will help to select patients who will respond to therapies targeting ERBB2 and other protein products of chromosome 17 loci.

Prediction of HER2 gene status in Her2 2+ invasive breast cancer: a study of 108 cases comparing ASCO/CAP and FDA recommendations

Most Her2 testing guidelines recommend that all cases scoring Her2 2+ by immunohistochemistry should be analyzed by fluorescent in situ hybridization (FISH) to determine HER2 status to confirm eligibility for Trastuzumab therapy in breast cancer. The aim of our study was to determine HER2 gene and chromosome 17 (CEN17) status in a series of 108 Her2 2+ consecutive cases and study the correlation between pathological characteristics of the tumors and HER2 amplification. Invasive breast cancers were tested by FISH using the Dako HER2 FISH pharmDx kit. The Her2 immunohistochemistry protocol was performed using the polyclonal AO485 antibody (Dako) diluted to 1:1500. HER2 and CEN17 status were correlated to tumor SBR grade, mitotic count, estrogen receptor, progesterone receptor status and percentage of Her2 immunohistochemistry-positive cells. Following Food and Drug Administration guidelines, ie, HER2/CEN17 ratio >or=2 and an HER2 copy number >4, amplified cases were observed in 36 (33%) and 49 (45%) cases, respectively, and following American Society of Clinical Oncology/College of American Pathologists guidelines, ie, HER2/CEN17 ratio >2.2 and an HER2 copy number >6, amplified cases represented 30 and 24% of the study population, respectively. Chromosome 17 polysomy (CEN17 >2.25) was observed in 39 (36%) tumors. Significant positive correlations were found between FISH HER2 amplified cases and Her2 immunostaining >60% (P=1.1.10(-5)), SBR grade 3 (P=0.0001), nuclear atypia (P=0.03) and mitotic count (P=0.008). By multivariate analysis, Her2 immunostaining >60% (P<10(-3)) and SBR grade 3 (P<10(-3)) were independent factors predicting HER2 amplification status irrespective to cutoff guidelines. All SBR grade 3 cases with more than 60% Her2+ cells had an HER2/CEN17 ratio >or=2, only one had a ratio <or=2.2. In our series of consecutive Her2 2+ cases, one-third demonstrated HER2 amplification, and one-third had chromosome 17 polysomy. Pathological factors, in particular SBR grade 3 and more than 60% Her2+ cells, were significantly correlated with HER2 amplification.

Is there a role for immunotherapy in osteosarcoma?

With the introduction of effective systemic chemotherapy, the prognosis for patients with osteosarcoma has improved dramatically. Estimates of overall survival for osteosarcoma patients prior to 1975 ranged from 5 to 20%, even for patients with localized disease of the extremity treated with amputation. The majority of these patients eventually developed pulmonary metastases and succumbed to their disease. The introduction of effective chemotherapy has dramatically improved the outcome of patients with localized disease, but has not altered the survival of patients with metastatic disease. Moreover, there has been little, if any, improvement in the outcomes of patients with localized disease since the mid-1980s. This has led to the investigation of other treatment approaches, including immunotherapy. Coincident with the initial development of chemotherapy, there were early attempts at immunotherapy. These met with little success. Subsequent approaches to harnessing the immune system have yielded more encouraging results. This chapter will review these various approaches, highlighting the role that immunotherapy might play in the multi-modality treatment of localized and metastatic osteosarcoma.

Development of automated brightfield double in situ hybridization (BDISH) application for HER2 gene and chromosome 17 centromere (CEN 17) for breast carcinomas and an assay performance comparison to manual dual color HER2 fluorescence in situ hybridization (FISH)

Background

Human epidermal growth factor receptor 2 (HER2) fluorescence in situ hybridization (FISH) is a quantitative assay for selecting breast cancer patients for trastuzumab therapy. However, current HER2 FISH procedures are labor intensive, manual methods that require skilled technologists and specialized fluorescence microscopy. Furthermore, FISH slides cannot be archived for long term storage and review. Our objective was to develop an automated brightfield double in situ hybridization (BDISH) application for HER2 gene and chromosome 17 centromere (CEN 17) and test the assay performance with dual color HER2 FISH evaluated breast carcinomas.

Methods

The BDISH assay was developed with the nick translated dinitrophenyl (DNP)-labeled HER2 DNA probe and DNP-labeled CEN 17 oligoprobe on the Ventana BenchMark^® XT slide processing system. Detection of HER2 and CEN 17 signals was accomplished with the silver acetate, hydroquinone, and H₂O₂ reaction with horseradish peroxidase (HRP) and the fast red and naphthol phosphate reaction with alkaline phosphatise (AP), respectively. The BDISH specificity was optimized with formalin-fixed, paraffin-embedded xenograft tumors, MCF7 (non-amplified HER2 gene) and BT-474 (amplified HER2 gene). Then, the BDISH performance was evaluated with 94 routinely processed breast cancer tissues. Interpretation of HER2 and CEN 17 BDISH slides was conducted by 4 observers using a conventional brightfield microscope without oil immersion objectives.

Results

Sequential hybridization and signal detection for HER2 and CEN 17 ISH demonstrated both DNA targets in the same cells. HER2 signals were visualized as discrete black metallic silver dots while CEN 17 signals were detected as slightly larger red dots. Our study demonstrated a high consensus concordance between HER2 FISH and BDISH results of clinical breast carcinoma cases based on the historical scoring method (98.9%, Simple Kappa = 0.9736, 95% CI = 0.9222 – 1.0000) and the ASCO/CAP scoring method with the FISH equivocal cases (95.7%, Simple Kappa = 0.8993%, 95% CI = 0.8068 – 0.9919) and without the FISH equivocal cases (100%, Simple Kappa = 1.0000%, 95% CI = 1.0000 – 1.0000).

Conclusion

Automated BDISH applications for HER2 and CEN 17 targets were successfully developed and it might be able to replace manual two-color HER2 FISH methods. The application also has the potential to be used for other gene targets. The use of BDISH technology allows the simultaneous analyses of two DNA targets within the context of tissue morphological observation.

Invasive ductal carcinoma of the breast with the "triple-negative" phenotype: prognostic implications of EGFR immunoreactivity

Invasive ductal carcinomas (IDC) of the breast with the triple negative phenotype (steroid hormone receptor absent, negative HER2 status) are characterized by poor clinical outcome. Additional tumor markers might allow identification of patients at higher risk. We evaluated clinical and biological features of 284 consecutive patients with pT1-3, pN1-3 M0 triple-negative IDC. Median follow-up was 70 months (interquartile range 59-94 months). Statistically significant worse disease-free and overall survival were observed in multivariate analysis, for patients with EGFR immunoreactivity in >or=50% invasive tumor cells (HR 2.39, 95% CI, 1.32-4.34, P = 0.004 for DFS; HR 2.34, 95% CI, 1.20-4.59 P = 0.01 for OS). Age >or= 70 years and PVI were additional independent predictors of reduced overall survival. EGFR immunoreactivity significantly correlates with worse prognosis in patients with triple-negative IDC, supporting further studies on the correlation between the degree of EGFR expression and outcome of triple negative breast cancer.

Polysomy 17 in breast cancer: clinicopathologic significance and impact on HER-2 testing

PURPOSE

Polysomy 17 is frequently found in breast cancer and may complicate the interpretation of HER-2 testing results. We investigated the impact of polysomy 17 on HER-2 testing and studied its clinicopathologic significance in relation to HER2 gene amplification.

PATIENTS AND METHODS

In 226 patients with primary invasive breast carcinoma, HER2 gene and chromosome 17 copy numbers were determined by dual-color fluorescent in situ hybridization (FISH). The interpretation of FISH results was based on either absolute HER2 gene copy number or the ratio HER2/chromosome 17. Results were correlated with HER-2 protein expression on immunohistochemistry (IHC), HER2 mRNA expression by reverse transcriptase polymerase chain reaction (RT-PCR), and with various clinicopathologic parameters.

RESULTS

All cases with an equivocal HER-2 result by FISH, either by absolute HER2 copy number (44 of 226 patients; 19.5%) or by the ratio HER2/chromosome 17 (three of 226 patients; 1.3%), displayed polysomy 17. On its own, polysomy 17 was not associated with HER-2 overexpression on IHC or increased HER2 mRNA levels by RT-PCR. Moreover, and in contrast with HER2 gene amplification, polysomy 17 was not associated with high tumor grade, hormone receptor negativity, or reduced disease-free survival.

CONCLUSION

Polysomy 17 affects HER-2 testing in breast cancer and is a major cause of equivocal results by FISH. We show that tumors displaying polysomy 17 in the absence of HER2 gene amplification resemble more HER-2-negative than HER-2-positive tumors. These findings highlight the need for clinical trials to investigative whether polysomy 17 tumors benefit from HER-2-targeted therapy.