Cytoplasmic staining of c-erbB-2 is not associated with the presence of detectable c-erbB-2 mRNA in breast cancer specimens

HER2 evaluation for clinical decision making in human solid tumours: pearls and pitfalls

The significant clinical benefits of human epidermal growth factor receptor 2 (HER2)-targeted therapeutic agents have revolutionized the clinical treatment landscape in a variety of human solid tumours. Accordingly, accurate evaluation of HER2 status in these different tumour types is critical for clinical decision making to select appropriate patients who may benefit from life-saving HER2-targeted therapies. HER2 biomarker scoring criteria is different in different organ systems, and close adherence to the corresponding HER2 biomarker testing guidelines and their updates, if available, is essential for accurate evaluation. In addition, knowing the unusual patterns of HER2 expression is also important to avoid inaccurate evaluation. In this review, we discuss the key considerations when evaluating HER2 status in solid tumours for clinical decision making, including tissue handling and preparation for HER2 biomarker testing, as well as pathologist's readout of HER2 testing results in breast carcinomas, gastroesophageal adenocarcinomas, colorectal adenocarcinomas, gynaecologic carcinomas, and non-small cell lung carcinomas.

Membranous or Cytoplasmic HER2 Expression in Colorectal Carcinoma: Evaluation of Prognostic Value Using Both IHC & BDISH

BACKGROUND

Human epidermal growth factor recptor-2 (HER2) was identified as a driver gene in several types of cancers with both prognostic and predictive value. However, the molecular association of HER2 gene mutation with HER2 gene amplification and/or protein expression in cancer tissues has not been clearly defined. Moreover, there is little information available on HER2 status role in tumor progression and metastasis in colorectal carcinoma (CRC) compared to other solid tumors. The aim of this study was to evaluate both HER2 amplification and protein expression profiles using immunohistochemistry (IHC) and bright-field dual in situ hybridization (BDISH) techniques, respectively.

PATIENTS AND METHODS

Tissue microarray (TMA) was constructed to accommodate a total of 243 CRC formalin-fixed paraffin embedded (FFPE) samples of consent patients and stained by IHC and BDISH methods. The expression patterns of HER2 protein status were evaluated and correlated to HER2 gene amplification status and then assessed for its prognostic value.

RESULTS

The expression profile of 58% samples showed cytoplasmic expression patterns of different categories. Interestingly, only 1% showed strong (+3) membranous expression pattern of HER2 with perfect match with their corresponding gene amplification status (>2). However, the cytoplasmic HER2 protein status did not show significant correlation with most clinicopathological features and survival outcomes except with age (p = 0.04) and tumor size (p = 0.03).

CONCLUSION

We demonstrated that the membranous HER2 gene/protein status is infrequent, while the main fraction of HER2 overexpression was cytoplasmic and lacking prognostic value. This cytoplasmic HER2 overexpression was induced through a gene-amplification independent pathway, making the HER2 gene status evaluation approach in those cases not worthy. Further investigations about the molecular pathways of the cytoplasmic HER2 protein in CRC and its associations with survival outcomes are required to allow either a breakthrough in CRC management; or to confirm the hypothesis of a marginal role in CRC onset and progression.

Raman-Encoded Molecular Imaging with Topically Applied SERS Nanoparticles for Intraoperative Guidance of Lumpectomy

Intraoperative identification of carcinoma at lumpectomy margins would enable reduced re-excision rates, which are currently as high as 20% to 50%. Although imaging of disease-associated biomarkers can identify malignancies with high specificity, multiplexed imaging of such biomarkers is necessary to detect molecularly heterogeneous carcinomas with high sensitivity. We have developed a Raman-encoded molecular imaging (REMI) technique in which targeted nanoparticles are topically applied on excised tissues to enable rapid visualization of a multiplexed panel of cell surface biomarkers at surgical margin surfaces. A first-ever clinical study was performed in which 57 fresh specimens were imaged with REMI to simultaneously quantify the expression of four biomarkers HER2, ER, EGFR, and CD44. Combined detection of these biomarkers enabled REMI to achieve 89.3% sensitivity and 92.1% specificity for the detection of breast carcinoma. These results highlight the sensitivity and specificity of REMI to detect biomarkers in freshly resected tissue, which has the potential to reduce the rate of re-excision procedures in cancer patients. Cancer Res; 77(16); 4506-16. ©2017 AACR.

A potential pitfall in evaluating HER2 immunohistochemistry for gastric signet ring cell carcinomas

Signet ring cell carcinoma (SRC) more commonly presents as metastatic disease and renders patients to be considered for chemotherapy. While treatment options are limited overall, trastuzumab has been shown to be effective for HER2 positive SRC cases. The current algorithm for HER2 evaluation heavily relies on positive membrane-specific staining by immunohistochemistry (IHC), but several anecdotal reports have suggested that SRCs may be susceptible to misinterpretation due to non-specific staining in the marginated cytoplasm with/without nucleus. Results of two FDA-approved IHC methods of HER2 evaluation, Pathway and HercepTest, along with silver in situ hybridisation were interpreted retrospectively and compared in 155 primary SRC cases. IHC results were discrepant between the two assays in SRC even at the strongest IHC scores. Discordance indeed occurred due to dark, non-specific staining obscured by the unique SRC morphology. True HER2 positive SRC was identified in three cases (3/155, 1.9%). In this study, we demonstrate the importance of recognising potential discrepancy in interpreting HER2 status depending on the assay used. Understanding this possible pitfall may prevent unnecessary trastuzumab in SRC patients.

HER-2 gene amplification in human breast cancer without concurrent HER-2 over-expression

BACKGROUND

Testing for human epidermal growth factor receptor-2 (HER-2) in breast cancer is performed by either immunohistochemistry (IHC) or in situ hybridization (ISH). The growth factor receptor-bound protein-7 (GRB7) gene is in close proximity to HER-2 on chromosome 17q11-12 and codes a signal transduction molecule shown to be an independent adverse marker in breast cancer.

METHODS

HER-2 and GRB7 protein expression from 613 frozen breast tumors was determined by Western analysis. HER-2 protein results were confirmed with IHC. Commercial HER-2 FISH was performed on a subset of tumors with multi-probe FISH used to assess the extent of HER-2 gene amplification. mRNA expression was determined by Multi-plex RT-PCR.

RESULTS

Seven tumors with GRB7 protein over-expression scored HER-2 FISH amplified but had no HER-2 protein over-expression. Four of the 7 tumors showed elevated GRB7 but not HER-2 mRNA over-expression. The breast cancer cell line HCC3153 did not over-express HER-2 protein but showed HER-2 FISH amplification of a limited segment around the HER-2 gene. Ten breast cancer tumors from the TCGA database had gene copy number increases around HER-2 without HER-2 mRNA or protein over-expression.

CONCLUSIONS

A subset of human breast cancers that test positive with FISH for HER-2 gene amplification do not over-express HER-2 protein. One mechanism for this discordance is the incomplete amplification of the smallest HER-2 region of chromosome 17q11-12, which includes GRB7. HER-2 gene amplification without protein over-expression is clinically significant because patients with such tumors are unlikely to benefit from HER-2 targeted therapy.

Cytoplasmic Overexpression of HER2: a Key Factor in Colorectal Cancer

Trastuzumab, a humanized mouse monoclonal antibody directed against HER2 (Human Epidermal Growth Factor Receptor 2), is currently a keystone in the treatment of breast cancer. Meanwhile, trastuzumab has been validated for use in other types of cancer too. But the data on HER2 expression in colorectal cancer are ambiguous, with reported overexpression of HER2 varying between zero and 84%. In this review these studies are evaluated and compared. It shows that many factors influence the determination of HER2-expression, especially of the intracellular fraction of HER2. It is concluded that although membranous overexpression of HER2 is low in colorectal cancer with only 5% of all patients being positive, a significant proportion of the patients (30%) shows cytoplasmic HER2 overexpression. The clinical impact of enhanced intracellular HER2 is not known, because the nature and origin have not completely been revealed yet. Enlightening this process could be a stepping stone towards targeting of intracellular HER2 as a treatment option.

Dual-colour HER2/chromosome 17 chromogenic in situ hybridisation enables accurate assessment of HER2 genomic status in ovarian tumours

BACKGROUND

Ovarian cancer is a leading cause of gynaecological cancer-related morbidity and mortality. There has been increasing interest in the potential utility of anti-human epidermal growth factor receptor 2 (anti-HER2) agents in the treatment of this disease, with the attendant need to identify suitable predictive biomarkers of response to treatment.

AIMS/METHODS

The authors studied the prevalence of HER2 genomic amplification and overexpression in 85 ovarian tumours in the local patient cohort of this study, as well as the concordance rate between immunohistochemistry, fluorescent in situ hybridisation (FISH) and a dual-colour HER2/chromosome 17 centromere chromogenic in situ hybridisation (CISH) assay.

RESULTS

The authors identified HER2 genomic amplification and protein overexpression in 35.3% (6/17) and 29.4% (5/17), respectively, of primary ovarian mucinous carcinomas. No other cancer subtypes displayed HER2 amplification or protein overexpression. The authors also found a perfect concordance between FISH and dual-colour CISH analysis (κ coefficient 1.0, p<0.001).

CONCLUSION

The results of this study support existing reports that HER2 genomic amplification and protein overexpression are predominantly found in primary ovarian mucinous carcinomas. Given the perfect concordance between the FISH and dual-colour CISH assays and the advantages of CISH over FISH analysis, future clinical trials investigating the use of anti-HER2 therapeutics in ovarian carcinomas should incorporate dual-colour CISH as part of the HER2 status assessment algorithm.

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.

Gastrointestinal Stromal Tumors: A Guide to the Diagnosis

Gastrointestinal stromal tumors (GISTs) have emerged from being a poorly understood and therapeutically refractory sarcoma to a tumor whose biology has not only provided insight into a mechanism of oncogenesis but has also led to a rational basis for therapy. Most GISTs are characterized by KIT protein (CD117) expression and constitutive activating mutations in either the c-kit or platelet-derived growth factor receptor α genes. This information can now be obtained from routine formalin-fixed and paraffin-embedded tissue. Because the correct diagnosis is the key to successful treatment of this tumor, it is incumbent on the pathologist to be familiar with the various gross and histologic patterns shown by these tumors. GISTs range from small incidental stromal nodules to large cystic and solid tumor masses. GISTs show a variety of microscopic patterns and therefore several other tumors enter the differential diagnosis. Fortunately, with an understanding of GIST histology, and with the proper use of immunohistochemistry and molecular analysis, a correct diagnosis can usually be made. In addition to the correct diagnosis, several key attributes of the tumor need to be determined because they provide the basis for proper clinical management. This article summarizes the gross, microscopic, and molecular findings of GISTs, and discusses the differential diagnosis and key attributes of this interesting group of neoplasms.

Aberrant c-erbB2 expression in cell clusters overlying focally disrupted breast myoepithelial cell layers: a trigger or sign for emergence of more aggressive cell clones?

Our recent studies revealed that cell clusters overlying focal myoepithelial cell layer disruption (FMCLD) had a significantly higher frequency of genetic instabilities and expression of invasion-related genes than their adjacent counterparts within the same duct. Our current study attempted to assess whether these cell clusters would also have elevated c-erbB2 expression. Human breast tumors (n=50) with a high frequency of FMCLD were analyzed with double immunohistochemistry, real-time RT-PCR, and chromogenic in situ hybridization for c-erbB2 protein and gene expression. Of 448 FMCLD detected, 404 (90.2%) were associated with cell clusters that had intense c-erbB2 immunoreactivities primarily in their cytoplasm, in contrast to their adjacent counterparts within the same duct, which had no or barely detectable c-erbB2 expression. These c-erbB2 positive cells were arranged as tongue-like projections, "puncturing" into the stroma, and about 20% of them were in direct continuity with tube-like structures that resembled blood vessels. Aberrant c-erbB2 expression was also seen in clusters of architecturally normal-appearing ducts that had distinct cytological abnormalities in both ME and epithelial cells, whereas not in their clear-cut normal counterparts. Molecular assays detected markedly higher c-erbB2 mRNA and gene amplification in cell clusters associated with FMCLD than in those associated with non-disrupted ME cell layers. Our findings suggest that cell clusters overlying FMCLD may represent the precursors of pending invasive lesions, and that aberrant c-erbB2 expression may trigger or signify the emergence of biologically more aggressive cell clones.

Detection of HER-2/neu gene amplification in breast carcinomas using quantitative real-time PCR - a comparison with immunohistochemical and FISH results

The aim of our study was to evaluate the value of quantitative real-time-PCR (qPCR) in the determination of HER-2/neu amplification status of human breast carcinomas by comparing qPCR, FISH and immunohistochemistry results from the same samples. A total of 210 breast carcinomas were examined. Ready-to-use CB11 antibody was applied to detect HER-2/neu oncoprotein expression. In 76 out of 210 cases FISH was performed, and 162 cases were investigated with qPCR. Seventy-five tumors were 2+ or 3+ positive with immunohistochemistry, while 135 samples were either completely negative or 1+. In 45 cases results from all three methods were available. Out of these, in twenty negative and sixteen positive cases both FISH and qPCR led to similar results. The mean qPCR amplification ratio in the concordant positive cases was 5.424 while in the qPCR+/FISH- group the mean ratio was 2.765. Out of 121 samples with scores of 0 or 1+ immunohistochemical result, analyzed also with qPCR, 26 showed HER-2/neu gene amplification. In these cases the mean amplification ratio was 2.53. Comparison of FISH and qPCR together with immunohistochemistry shows that qPCR is more sensitive to detect HER-2/neu gene amplification in tumors scored as 2+ with immunohistochemistry, but the diagnostic cut-off ratio should be defined above 2.7 to avoid high number of false positive cases. Amongst the immunohistochemistry score 2+ cases, 10 of 18 showed gene amplification by qPCR while 10 of 26 by FISH. In conclusion, a well calibrated HER-2/neu qPCR assay may serve as useful alternative to FISH in breast cancer patients.

The correlation between cytoplasmic overexpression of epidermal growth factor receptor and tumor aggressiveness: poor prognosis in patients with pancreatic ductal adenocarcinoma

OBJECTIVES

Recent studies have shown that some growth factor receptors with tyrosine kinase activity, eg, the epidermal growth factor receptor (EGFr) and the c-erbB-2 (HER-2) oncoprotein, are associated with aggressive biologic behavior of various cancer cell types. We examined the clinicopathological significance of the expression and localization of EGFr and HER-2 in both invasive and intraductal components of ductal adenocarcinomas of the pancreas.

METHODS

Tissue samples from 76 archival cases of pancreatic ductal adenocarcinoma were immunohistochemically analyzed for both membrane and cytoplasmic overexpression of EGFr and HER-2 oncoprotein. The rate of incidence between the invasive and intraductal components was analyzed and then their correlation with tumor differentiation and patient prognosis was analyzed.

RESULTS

Cytoplasmic EGFr overexpression was more frequent in invasive components (47 of 76, 62%) than in intraductal components (19 of 76, 25%), while membrane EGFr overexpression was more frequent in intraductal components (41 of 76, 54%) than in invasive components (11 of 76, 14%). The membrane HER-2 overexpression was also more frequent in intraductal components (15 of 76, 20%) than in invasive components (2 of 76, 3%), but the incidence of cytoplasmic HER-2 overexpression did not differ between intraductal components (12 of 76, 16%) and invasive components (8 of 76, 11%). The cytoplasmic EGFr overexpression in invasive components was more frequent in grade 3 group (32 of 33, 97%) than in grade 2 (15 of 32, 47%) and grade 1 groups (0 of 10, 0%) (P < 0.001). Patients with adenocarcinoma with cytoplasmic EGFr overexpression showed shorter overall survival than those with adenocarcinoma without cytoplasmic EGFr overexpression (P = 0.02).

CONCLUSION

It is suggested that the cytoplasmic overexpression of EGFr plays a significant role in the progression of pancreatic ductal adenocarcinoma, especially in the invasion and acquisition of aggressive clinical behavior. Both membrane and cytoplasmic expression of HER-2 showed no significant correlation between tumor differentiation and poor survival.

HER-2 receptor expression, localization, and activation in colorectal cancer cell lines and human tumors

The HER-2/neu oncogene encodes a 185 kD protein that is phosphorylated upon ligand binding to other HER/erbB members and regulates cell growth and differentiation. Given that HER-2 receptor blockade can inhibit the growth of colon cancer cell lines and tumor xenografts, we investigated the frequency, localization and phosphorylation status of HER-2 in colon cancer cell lines and in human tumors. Protein expression was analyzed in relation to mRNA levels, HER-2 amplification, and clinicopathological variables. Colon cancer cell lines constitutively expressed HER-2 proteins and none showed HER-2 amplification by fluorescence in situ hybridization. Cell fractionation and immunoblotting showed HER-2 in both the membrane and cytosolic compartments. Primary colorectal carcinomas (n = 96) and their metastases (n = 25) were examined by immunohistochemistry. Strong membrane HER-2 staining was detected in 5 (5%) of primaries and in 3 (12%) metastases (p = 0.36). Membrane but not cytoplasmic localization was strongly associated with HER-2 gene amplification (p = 0.007). Cytoplasmic HER-2 staining was found in 61 (63.5%) of primary tumors and localization was confirmed by immunoelectron microscopy that also showed plasma membrane HER-2. Using real-time quantitative RT-PCR, HER-2 mRNA was increased in tumors with membrane compared to cytoplasmic staining (r = 0.66, p = 0.001). Cytoplasmic HER-2 was associated with tumor differentiation (p = 0.018), but not other clinicopathological variables. By immunoblotting, heterogeneity was seen in HER-2 levels with downregulation in 4 of 7 tumors relative to normal epithelia that uniformly expressed HER-2. Phosphorylated HER-2 was detected in approximately 50% of tumors and in normal mucosa. In conclusion, HER-2 is expressed constitutively in colon cancer cell lines and demonstrates relatively distinct localization patterns in human tumors. Strong membrane immunoreactivity is associated with high levels of HER-2 mRNA and gene amplification whereas cytoplasmic HER-2 is detected frequently and seems to be a marker of tumor differentiation.

Induction of protein catabolism in myotubes by 15(S)-hydroxyeicosatetraenoic acid through increased expression of the ubiquitin-proteasome pathway

The potential role of 15(S)-hydroxyeicosatetraenoic acid (15(S)-HETE) as an intracellular signal for increased protein catabolism and induction of the expression of key components of the ubiquitin-proteasome proteolytic pathway induced by a tumour cachectic factor, proteolysis-inducing factor has been studied in murine C(2)C(12) myotubes. 15(S)-HETE induced protein degradation in these cells with a maximal effect at concentrations between 78 and 312 nM. The effect was attenuated by the polyunsaturated fatty acid, eicosapentaenoic acid (EPA). There was an increase in 'chymotrypsin-like' enzyme activity, the predominant proteolytic activity of the proteasome, in the same concentration range as that inducing total protein degradation, and this effect was also attenuated by EPA. 15(S)-hydroxyeicosatetraenoic acid also increased maximal expression of mRNA for proteasome subunits C2 and C5, as well as the ubiquitin-conjugating enzyme, E2(14k), after 4 h incubation, as determined by quantitative competitive RT-PCR. The concentrations of 15-HETE affecting gene expression were the same as those inducing protein degradation. Western blotting of cellular supernatants of myotubes treated with 15(S)-HETE for 24 h showed increased expression of p42, an ATPase subunit of the regulatory complex at similar concentrations, as well as a decrease in expression of myosin in the same concentration range. 15(S)-hydroxyeicosatetraenoic acid activated binding of nuclear factor-kappaB (NF-kappaB) in the myotube nucleus and stimulated degradation of I-kappaBalpha. The effect on the NF-kappaB/I-kappaBalpha system was attenuated by EPA. In addition, the NF-kappaB inhibitor peptide SN50 attenuated the increased chymotrypsin-like enzyme activity in the presence of 15(S)-HETE. These results suggest that 15(S)-HETE induces degradation of myofibrillar proteins in differentiated myotubes through an induction of an increased expression of the regulatory components of the ubiquitin-proteasome proteolytic pathway possibly through the intervention of the nuclear transcription factor NF-kappaB, and that this process is inhibited by EPA.

[Evaluation of her-2/neu amplification/overexpression in OSCC with fluorescence in situ hybridization (FISH) and immunohistochemistry]

INTRODUCTION

The human epidermal growth factor receptor ( her-2/ neu) protooncogene encodes a membrane tyrosine kinase with homology to the epidermal growth factor receptor (EGFR). Amplification and protein overexpression have been identified in various solid tumors and a significant association with poor clinical outcome was reported. This investigation was performed to assess the frequency of her-2/ neu overexpression and to compare these results with clinical outcome in OSCC.

MATERIAL AND METHODS

Archival biopsy specimens from 97 untreated OSCCs were evaluated using a polyclonal antibody A0485 (Dako). Only membrane staining intensity and pattern were evaluated according to the guidelines of the clinical trial assay recommendations (0-3+) for breast carcinoma. Score 0 and 1+ were interpreted as negative for HER-2/NEU protein overexpression and 2+ and 3+ as positive. FISH analysis with directly labeled probes for her-2/ neu and chromosome 17 was performed on the same specimens. The ratio between her-2/ neu and chromosome 17 signals was calculated after selection of 20-40 non-overlapping tumor cells. The tumor was considered amplified if the ratio was above 2.

RESULTS

In 11 out of 97 biopsies (11.3%) membranous overexpression (score 2+ and 3+) of her-2/ neu was shown by immunohistochemistry. FISH analysis in 42 cases revealed amplification in 14 cases. Concordance between immunohistochemistry and FISH was found in 86%. Clinical-pathological data as well as survival revealed no correlation with her-2/ neu status.

DISCUSSION

In spite of missing correlation between survival and her-2/ neu overexpression in our study, the predictive value of the her-2/ neu protooncogene in adjuvant therapy in OSCC needs further investigation.

Malignant mesothelioma does not demonstrate overexpression or gene amplification despite cytoplasmic immunohistochemical staining for c-Erb-B2

BACKGROUND

Previous studies have shown conflicting results regarding the expression of c-Erb-B2 in malignant mesothelioma. Overexpression of the c-erb-B2 gene product in a subset of mesothelioma may have prognostic or therapeutic implications.

OBJECTIVE

To determine whether malignant mesothelioma demonstrates c-Erb-B2 overexpression and, if so, whether such overexpression correlates with gene amplification.

METHODS

Immunohistochemistry, reverse transcription-polymerase chain reaction, and fluorescent in situ hybridization were used to analyze archived tissue from 37 cases of malignant mesothelioma.

RESULTS

Although immunohistochemical staining for c-Erb-B2 was detected in most mesotheliomas, the staining was cytoplasmic and was not consistent between the 2 different primary antibodies used. Moreover, even cases with strong cytoplasmic staining for c-Erb-B2 did not demonstrate increased messenger RNA levels or gene copy numbers compared to cases that demonstrated no staining.

CONCLUSIONS

Cytoplasmic immunoreactivity for c-Erb-B2 in mesothelioma does not represent gene overexpression or amplification and may be an immunohistochemical artifact.

Evaluation of monoclonal humanized anti-HER2 antibody, trastuzumab, in patients with recurrent or refractory ovarian or primary peritoneal carcinoma with overexpression of HER2: a phase II trial of the Gynecologic Oncology Group

PURPOSE

To evaluate the feasibility, toxicity, and efficacy of single-agent monoclonal antibody therapy targeting the human epidermal growth factor receptor 2 (HER2)/neu receptor in ovarian and primary peritoneal carcinoma.

PATIENTS AND METHODS

Eligible patients had measurable persistent or recurrent epithelial ovarian or primary peritoneal carcinoma with 2+ or 3+ HER2 overexpression documented by immunohistochemistry. Intravenous trastuzumab was administered initially at a dose of 4 mg/kg, then weekly at 2 mg/kg. Patients without progressive disease or excessive toxicity could continue treatment indefinitely. Those with stable or responding disease at 8 weeks were offered treatment at a higher weekly dose (4 mg/kg) at time of progression. Patient sera were analyzed for the presence of the soluble extracellular domain of HER2, host antibodies against trastuzumab, and trastuzumab pharmacokinetics.

RESULTS

A total of 837 tumor samples were screened for HER2 expression, and 95 patients (11.4%) exhibited the requisite 2+/3+ expression level. Forty-five patients, all of whom received prior chemotherapy, were entered, and 41 were deemed eligible and assessable. There were only mild expected toxicities and no treatment-related deaths. Although an elevated level of the soluble extracellular domain of HER2 was detected in eight of 24 patients, serum HER2 was not associated with clinical outcome. There was no evidence of host antitrastuzumab antibody formation. Serum concentrations of trastuzumab gradually increased with continued therapy. An overall response rate of 7.3% included one complete and two partial responses. Median treatment duration was 8 weeks (range, 2 to 104 weeks), and median progression-free interval was 2.0 months.

CONCLUSION

The clinical value of single-agent trastuzumab in recurrent ovarian cancer is limited by the low frequency of HER2 overexpression and low rate of objective response among patients with HER2 overexpression.

Identification of mRNAs differentially-expressed between benign and malignant breast tumour cells

Two suppression subtracted cDNA libraries have been constructed, one containing cDNAs to mRNAs present at a higher level in a benign human breast tumour-derived cell line relative to the malignant mammary cell line, MCF-7, and the other containing cDNAs present at a higher level in the MCF-7 cells relative to the benign cells. Randomly-picked cloned DNAs have been sequenced yielding 29 and 128 different cDNAs from the benign and malignant libraries, respectively. Using reverse Northern hybridisation, 76% and 83% of the cDNAs were differentially expressed by greater than two-fold, whilst 14% and 11% of cDNAs in the respective libraries were differentially expressed by more than 15-fold. Amongst these were oestrogen-responsive cDNAs and expressed sequence tags. One such oestrogen-responsive expressed sequence tag, M41, is transcribed from a gene located on chromosome 21q22.3, within an intron of a larger gene. The M41 gene contains oestrogen response elements, one of which is associated with alu repeats. M41 mRNA is expressed at a statistically significantly higher level in human breast cancer specimens than in normal human breast and benign lesions. In carcinomas, its up-regulation is associated with the development of the malignant cell.

C-myc oncogene amplification in ductal carcinoma in situ of the breast

The c-myc oncogene is frequently activated in invasive breast cancer and has been associated with high nuclear grade, lymph node metastasis and poorer disease outcome. We have examined c-myc oncogene amplification using fluorescence in situ hybridization in a series of 96 pure DCIS. Additionally we assessed amplification and expression of the Her2 and bcl-2 oncogenes. The findings were compared with clinicopathological data, Ki-67 proliferative index and hormone receptor status. We observed c-myc oncogene amplification in 19 tumours (20%). These cases were significantly associated with an average of 38% higher proliferative activity (p = 0.045), a 43% larger tumour size (p = 0.029) and the otherwise rare micropapillary subtype (p = 0.0005). Concluding the c-myc oncogene appears to be involved in the development of a more aggressive phenotype of DCIS.

Expression of uncoupling proteins-1, -2 and -3 mRNA is induced by an adenocarcinoma-derived lipid-mobilizing factor

The abnormalities of lipid metabolism observed in cancer cachexia may be induced by a lipid-mobilizing factor produced by adenocarcinomas. The specific molecules and metabolic pathways that mediate the actions of lipid-mobilizing factor are not known. The mitochondrial uncoupling proteins-1, -2 and -3 are suggested to play essential roles in energy dissipation and disposal of excess lipid. Here, we studied the effects of lipid-mobilizing factor on the expression of uncoupling proteins-1, -2 and -3 in normal mice. Lipid-mobilizing factor isolated from the urine of cancer patients was injected intravenously into mice over a 52-h period, while vehicle was similarly given to controls. Lipid-mobilizing factor caused significant reductions in body weight (-10%, P=0.03) and fat mass (-20%, P<0.01) accompanied by a marked decrease in plasma leptin (-59%, P<0.01) and heavy lipid deposition in the liver. In brown adipose tissue, uncoupling protein-1 mRNA levels were elevated in lipid-mobilizing factor-treated mice (+96%, P<0.01), as were uncoupling proteins-2 and -3 (+57% and +37%, both P<0.05). Lipid-mobilizing factor increased uncoupling protein-2 mRNA in both skeletal muscle (+146%, P<0.05) and liver (+142%, P=0.03). The protein levels of uncoupling protein-1 in brown adipose tissue and uncoupling protein-2 in liver were also increased with lipid-mobilizing factor administration (+49% and +67%, both P=0.02). Upregulation by lipid-mobilizing factor of uncoupling proteins-1, -2 and -3 in brown adipose tissue, and of uncoupling protein-2 in skeletal muscle and liver, suggests that these uncoupling proteins may serve to utilize excess lipid mobilized during fat catabolism in cancer cachexia.

S100A4 (p9Ka) protein in colon carcinoma and liver metastases: association with carcinoma cells and T-lymphocytes

The presence of the EF-hand-calcium-binding protein S100A4 in the carcinoma cells of the primary tumour is associated with a shorter survival time of a group of breast cancer patients. In colon cancer, primary tumours as well as metastases to the liver can be studied. Here we show, using quantitative PCR applied to RNA from 24 normal colon, four liver tissues, 24 colon carcinoma specimens, and 24 livers containing colonic carcinoma metastases, that the level of S100A4 mRNA was significantly higher in the carcinomas compared to normal specimens (Mann-Whitney U-test, P=0.05), and in liver metastases compared to carcinoma specimens (P=0.039). The latter comparison included seven liver metastases and their matched primary carcinomas (P<0.001) from the same patient. In situ hybridization and immunocytochemistry techniques have localized S100A4 to both carcinoma cells and lymphocytes in the malignant specimens. The percentage of specimens stained for S100A4 in the epithelial cells is significantly higher for those isolated from carcinomas and metastases than from the corresponding normal tissue, and from metastases than from corresponding carcinoma (Fisher Exact text, P<0.0016, P=0.04, respectively). In most specimens, S100A4 is present in clusters of T lymphocytes and this distribution is also found in the lymphoid, uninflamed appendix.

EGFR family expression in breast carcinomas. c-erbB-2 and c-erbB-4 receptors have different effects on survival

One hundred patients with breast carcinoma followed for 7-11 years were included in the present study of EGFR family members, using immunohistochemistry and RT-PCR. By immunohistochemistry, 36%, 27%, 26%, and 82% of the tumours were positive for EGFR, c-erbB-2, c-erbB-3, and c-erbB-4. All the immunoreactive tumours were confirmed positive by RT-PCR. Tumour size, histological grade, lymph node status, S-phase fraction, and stage were confirmed to be significantly associated with both disease-free and cancer-specific survival in the present study. Methods of treatment, histological type, and ploidy had no significant effect on survival. Statistical analysis of EGFR family members in these tumours showed a significant association between c-erbB-2 expression and reduced disease-free and cancer-specific survival. c-erbB-4 expression was associated with a more favourable outcome. Co-expression of c-erbB-2 and EGFR was associated with a worse prognosis. c-erbB-4 expression, however, showed an antagonistic effect on the clinical influence of c-erbB-2 expression. In conclusion, c-erbB-2 expression in breast carcinomas is associated with an unfavourable clinical course and EGFR expression has a synergistic effect. However, c-erbB-4 antagonizes the c-erbB-2 effect on clinical course in breast carcinomas. To achieve best results with immunotherapy against the c-erbB-2 receptor, clarifying the status of c-erbB-4 expression may be of significance.

Cachexia in MAC16 adenocarcinoma: suppression of hunger despite normal regulation of leptin, insulin and hypothalamic neuropeptide Y

Weight loss normally stimulates hunger, through mechanisms that include falls in circulating leptin and insulin, leading to stimulation of hypothalamic neuropeptide Y (NPY). Here, we investigated the leptin, insulin and NPY to clarify why hunger is suppressed in mice with severe cachexia due to the MAC16 adenocarcinoma. MAC16-bearing mice progressively lost weight (19% below controls) and fat (- 61%) over 16 days after tumour transplantation, while total food intake fell by 10%. Pair-fed mice showed less wasting, with final weight being 9% and fat mass 25% below controls. Plasma leptin fell by 85% in MAC16 and 51% in pair-fed mice, in proportion to loss of fat. Plasma insulin was also reduced by 49% in MAC16 and 53% in pair-fed groups. Hypothalamic leptin receptor (OB-Rb) mRNA was significantly increased in both MAC16 (+ 223%) and pair-fed (+192%) mice. Hypothalamic NPY mRNA was also significantly raised in MAC16 (+152%) and pair-fed (+ 99%) groups, showing negative correlations with plasma leptin and insulin, and a positive association with OB-Rb mRNA. In MAC16-induced cachexia, leptin production and hypothalamic OB-Rb and NPY expression are regulated appropriately in response to fat depletion. Therefore, suppression of hunger is probably due to tumour products that inhibit NPY transport or release, or that interfere with neuronal targets downstream of NPY.

Her-2/neu and breast cancer

Breast cancer is the most common malignancy in women in the United States in the year 2000. The proto-oncogene Her-2/neu (c-erb-B2) has become an increasingly important prognostic and predictive factor in breast cancer. Overexpression/amplification of the Her-2/neu has been associated with a worse outcome in patients with breast cancer. Herceptin, a "humanized" murine monoclonal antibody directed against the extracellular domain of the Her-2/neu protein, is being used to treat breast cancer that overexpresses Her-2/neu. The status of Her-2/neu in the tumor has become a critical factor in the management strategy of a breast cancer patient. The objective of this article is to provide a comprehensive review of all aspects of Her-2/neu in breast cancer, including biology, prognostic and predictive value, targeted Herceptin therapy, and the laboratory testing of Her-2/neu.

The HER-2/neu oncogene in tumors of the gastrointestinal tract

The HER-2/neu oncogene is localized to chromosome 17q and shares significant homology with the epidermal growth factor receptor. As a result of its potential role in the selection of therapy, HER-2/neu testing has reached near-standard-of-practice status in breast cancer. There is considerable interest in HER-2/neu as a prognostic factor and target of therapy in tumors of the gastrointestinal tract. In this review of HER-2/neu expression in esophageal squamous cell carcinoma and adenocarcinomas of the esophagus, stomach, and colon, a wide range of expression of HER-2/neu from 0 to 83% likely reflects both differences in methods and reagents, as well as study bias associated with patient selection (i.e., early versus advanced disease). For esophageal squamous cell carcinoma, little information exists as to the prognostic significance of HER-2/neu expression. In adenocarcinoma associated with Barrett's esophagus there is contradictory data. However, most of the information available indicates that this marker has significant prognostic value. In gastric adenocarcinoma, the wide expression range may truly reflect patient selection because HER-2/neu positivity appears linked to advanced rather than early disease with limited invasion. The majority of studies favor a significant prognostic value of HER-2/neu status for this tumor. Finally, in colorectal cancer HER-2/neu overexpression also appears to be a significant adverse outcome indicator as judged by the current published literature. In conclusion, given that either HER-2/neu protein overexpression or gene amplification is associated with approximately one-fourth of all gastrointestinal tract malignancies, strategies designed to employ the marker in therapy selection appear warranted. During the next several years it will not be surprising to see these tumors treated with antiHER-2/neu modalities such as Herceptin, likely in combination with other agents initially for patients with advanced disease, and possibly for individuals with high-risk lesions in an adjuvant setting.

Type 1 protein tyrosine kinases in Chinese breast carcinomas: a clinicopathologic study

Immunostaining for epidermal growth factor receptor (EGFR), c-erbB-2, c-erbB-3, c-erbB-4, ER, and PR was performed in 107 cases of primary breast carcinomas from Anyang, China. The expression rates of EGFR, c-erbB-2, c-erbB-3 and c-erbB-4 in this series were 43.9%, 36%, 27%, and 45.8%, respectively, and a stronger c-erbB-4 staining of "normal" glandular structures inside tumors and in the vicinity of tumor clusters was confirmed. Larger tumor size, lymph node metastases, and higher histologic grade in invasive ductal carcinomas were shown to be statistically valuable negative prognostic factors, and c-erbB-2 expression was also weakly associated with a poor prognosis no matter what the nodal status. The expressions of c-erbB-4 and ER in invasive ductal carcinomas were inversely associated with histologic grade of the tumors. Associations between the expression of c-erbB-4 and ER (p = 0.001) and the expression of ER and PR study (p = 0.004) were found in the present study. No significant associations between the expressions of EGFR, c-erbB-3, c-erbB-4, ER, and PR and overall survival were detected. The expression of c-erbB-4 in the node negative group was, however, associated with a better prognosis, indicating a different role of c-erbB-4 protein in breast tumor development than other EGFR family members have. Int J Surg Pathol 9(3):177-187, 2001

Quantitative evaluation of HER-2/neu status in breast cancer by fluorescence in situ hybridization and by immunohistochemistry with image analysis

We correlated quantitative results obtained in 40 invasive breast cancer cases for HER-2 gene amplification by fluorescence in situ hybridization with protein expression by immunohistochemical studies with computer-assisted image analysis. Fluorescence in situ hybridization (FISH) results were quantified as the mean number of fluorescent signals per nucleus, and immunohistochemical slides were read by semiquantitatively assessing membranous immunostaining intensity in tumor cells vs nonneoplastic breast tissue or quantitatively evaluated by image analysis. We found high correlation between immunohistochemical results by semiquantitative scoring and by image analysis. FISH results correlated with immunohistochemical results moderately when the staining intensity of only tumor cells was assessed and significantly better when the difference in staining intensity between tumor cells and nonneoplastic breast tissue was assessed. The correlation with FISH results was further improved when immunohistochemical study was combined with heat-induced epitope retrieval (HIER). Although FISH and immunohistochemical studies assess different aspects of the HER-2/neu gene (amplification vs overexpression), we found good correlation between the diagnostic techniques. The correlation was best when immunohistochemical studies were combined with HIER and assessed as the difference between tumor cells and nonneoplastic breast tissue.

Markers of neck failure in oral cavity and oropharyngeal carcinomas treated with radiotherapy

BACKGROUND

Neck management after radiotherapy remains controversial. It is not clear which patients may benefit from postradiotherapy neck dissection. Biologic markers may be useful in this setting.

METHOD

This study includes 81 patients with oral cavity and oropharyngeal carcinomas. The primary tumor had been treated with radical radiotherapy. Immunohistochemical staining to p53, ki-67, NEU, HSP-27, and GST has been performed.

RESULTS

There were 50 T1-2 and 31 T3-4 patients, as well as 36 NO and 45 N1-3. A total of 25 nodal failures was observed. With expressed HSP2, 23% of patients had neck failure compared with 51% when HSP-27 was absent (p = .02). With NEU overexpression, nodal control decreased from 72% to 34% (p = .008). In a Cox model, NEU (p = .01) and HSP-27 (p = .05) were associated with neck failure.

CONCLUSIONS

HSP-27 and NEU expression may play a role in predicting nodal failure. This should be confirmed in a larger, prospective study.

Overexpression of HER2/neu in solid tumours: an immunohistochemical survey

AIMS

Using a standardized immunohistochemical assay we have evaluated 575 primary neoplasms of different histogenesis to determine the incidence of HER2 overexpression in some of the most common categories of human solid neoplasms. This study addresses the variable incidence of HER2 overexpression previously published for some tumour types.

METHODS AND RESULTS

The immunohistochemical staining was performed on paraffin sections of surgical specimens and a well-defined scoring system based upon numbers of HER2 receptors expressed on the cell surface was applied. Overexpression of HER2 as defined as a HER2 score of equal or greater than 2 was seen in breast cancer (22%), pulmonary adenocarcinoma (28%), colorectal adenocarcinomas (17%), pulmonary squamous (11%) and gastric adenocarcinomas (11%). As expected, the proportion of cases with a HER2 score of 3 was highest in breast cancer. Contrary to published results prostate and pancreas adenocarcinomas showed a very low incidence of HER2 overexpression.

CONCLUSIONS

Overexpression of HER2 is detected immunohistochemically in a proportion of epithelial neoplasms of diverse histogenesis in addition to ductal breast cancer. The standardized format of the assay will allow comparative analyses of studies performed at different institutions.

E-Cadherin complex protein expression and survival in ovarian carcinoma

OBJECTIVE

The aim of this study was to analyze the correlation between expression of E-cadherin complex proteins, epidermal growth factor receptor (EGFR), and c-erbB-2 and disease outcome in advanced-stage ovarian carcinomas.

METHODS

Sections from 75 primary ovarian carcinomas (=37) and metastatic lesions (=38) from 45 patients diagnosed with advanced-stage ovarian carcinoma (FIGO stage III-IV) were immunostained and evaluated for staining pattern, extent, and intensity. Patients were divided in two groups based on disease outcome. Long-term survivors (21 patients) and short-term survivors (24 patients) were defined using a double cutoff of 36 months for disease-free survival (DFS) and 60 months for overall survival (OS). Mean follow-up period was 70 months. The mean values for DFS and OS were 109 and 125 months for long-term survivors, as compared to 3 and 21 months for short-term survivors, respectively.

RESULTS

Comparison of all primary and metastatic lesions showed upregulation of gamma-catenin protein expression in the latter (P = 0.05). When segregated according to disease outcome, the expression of all studied proteins, with the exception of EGFR, was more diffuse in tumors of short-term survivors. The presence of cytoplasmic staining for c-erbB-2 was associated with poor survival in the entire cohort (P = 0.007), as well as in primary tumors alone (P = 0.003), in survival analysis. Similar results were seen in the evaluation of primary tumors for gamma-catenin (P = 0.002).

CONCLUSIONS

gamma-Catenin, and possibly c-erbB-2, are valid markers of poor survival in advanced-stage ovarian carcinoma.

Expression of calcium-binding protein S100A2 in breast lesions

A suppression subtraction cDNA library representing mRNAs expressed at a higher level in a benign breast tumour-derived cell line relative to the malignant MCF-7A cell line contained cDNAs corresponding to mRNAs for plasminogen activator inhibitor I, annexin VIII and the EF-hand protein S100A2. S100A2 protein has previously been shown to be expressed in normal human breast epithelium, but not in human breast carcinoma cell lines. Using a PCR-based assay and in situ hybridization on histological sections of human breast specimens, the mRNA for S100A2 was shown to be present in all benign breast lesions examined as well as in normal epithelium. S100A2 mRNA was detectable in 37% of specimens of carcinoma in situ, but in less than 15% of carcinoma specimens. The results suggest that the loss of S100A2 is associated with the development of malignant cells and is not associated with early tumour development.

Short-term breast cancer prediction by random periareolar fine-needle aspiration cytology and the Gail risk model

BACKGROUND

: Biomarkers are needed to refine short-term breast cancer risk estimates from epidemiologic models and to measure response to prevention interventions. The purpose of our study was to determine whether the cytologic appearance of epithelial cells obtained from breast random periareolar fine-needle aspirates or molecular marker expression in these cells was associated with later breast cancer development.

METHODS

: Four hundred eighty women who were eligible on the basis of a family history of breast cancer, prior precancerous biopsy, and/or prior invasive cancer were enrolled in a single-institution, prospective trial. Their risk of breast cancer according to the Gail model was calculated, and random periareolar fine-needle aspiration was performed at study entry. Cells were characterized morphologically and analyzed for DNA aneuploidy by image analysis and for the expression of epidermal growth factor receptor, estrogen receptor, p53 protein, and HER2/NEU protein by immunocytochemistry. All statistical tests are two-sided.

RESULTS

: At a median follow-up time of 45 months after initial aspiration, 20 women have developed breast cancer (invasive disease in 13 and ductal carcinoma in situ in seven). With the use of multiple logistic regression and Cox proportional hazards analysis, subsequent cancer was predicted by evidence of hyperplasia with atypia in the initial fine-needle aspirate and a 10-year Gail projected probability of developing breast cancer. Although expression of epidermal growth factor receptor, estrogen receptor, p53, and HER2/NEU was statistically significantly associated with hyperplasia with atypia, it did not predict the development of breast cancer in multivariable analysis.

CONCLUSION

: Cytomorphology from breast random periareolar fine-needle aspirates can be used with the Gail risk model to identify a cohort of women at very high short-term risk for developing breast cancer. We recommend that cytomorphology be studied for use as a potential surrogate end point in prevention trials.

Complexity of signal transduction mediated by ErbB2: clues to the potential of receptor-targeted cancer therapy

The erbB2 oncogene belongs to the type I trans-membrane tyrosine kinase family of receptors. Its medical importance stems from its widespread over-expression in breast cancer. This review will focus on the signal transduction through this protein, and explains how the overexpression of erbB2 may result in poor prognosis of breast cancer, and finally it will summerize our current understanding about the therapeutic potential of receptor-targeted therapy in breast cancer. ErbB2 does not have any known ligand which is able to bind to it with high affinity. However the kinase activity of erbB2 can be activated without any ligand, if it is overexpressed, and by heteroassociation with other members of the erbB family (erbB1 or epidermal growth factor receptor, erbB3 and erbB4). This interaction substantially increases the efficiency and diversity of signal transduction through these receptor complexes. In addition, erbB2 forms large scale receptor clusters containing hundreds of proteins. These receptor islands may take part in recruiting cytosolic factors which relay the signal towards the nucleus or the cytoplasm. Overexpression of erbB2 was linked to higher transforming activity, increased metastatic potential, angiogenesis and drug resistence of breast tumor in laboratory experiments. As a corollary of these properties, erbB2 amplification is generally thought to be associated with a poor prognosis in breast cancer patients. These early findings lead to the development of antibodies that down-regulate erbB2. Such a therapeutic approach has already been found effective in experimental tumor models and in clinical trials as well. Further understanding of the importance of erbB2 and growth factor receptors in the transformation of normal cells to malignant ones may once give us a chance to cure erbB2 over-expressing breast cancer.