c-erbB-2 overexpression in the dysplasia/carcinoma sequence of Barrett's oesophagus

Molecules involved in the development of Barrett's esophagus phenotype in chronic eosinophilic esophagitis

This paper aims to investigate the molecules involved in development of Barrett's esophagus (BE) in human eosinophilic esophagitis (EoE). Histopathological, immunohistochemical, real-time PCR Immuno blot, and ELISA analyses are performed to identify the signature genes and proteins involved in the progression of BE in EoE. We detected characteristic features of BE like intermediate columnar-type epithelial cells, induced BE signature genes like ErbB3, CDX1, ErbB2IP in the esophageal mucosa of patients with EoE. In addition, we had observed several BE-associated proteins such as TFF3, p53 and the progression markers like EGFR, p16, MICA, MICB, and MHC molecules in esophageal biopsies of patients with chronic EoE. Interestingly, we also detected mucin-producing columnar cells and MUC-2, MUC-4, and MUC5AC genes and proteins along with induced IL-9 in patients with chronic EoE. A strong correlation of IL-9 with mucin genes is observed that implicated a possible role for IL-9 in the transformation of esophageal squamous epithelial cells to columnar epithelial cells in patients with EoE. These findings indicate that IL-9 may have an important role in BE development in patients with chronic EoE. We also discovered that IL-9 stimulates mucin-producing and barrier cell transcripts and proteins such CK8/18, GATA4, SOX9, TFF1, MUC5AC, and tight junction proteins in primary esophageal epithelial cells when exposed to IL-9. Taken together, these findings provide evidence that indeed IL-9 has a role in the initiation and progression of BE characteristics like development of mucin-producing columnar epithelial cells in patients with chronic EoE.NEW & NOTEWORTHY Intermediate columnar-type epithelial cells are observed in biopsies of patients with EoE. Induced BE signature genes (CK8/18, CDX1 GATA4, SOX9, and Occludin) were observed in patients with chronic EoE. Induction of IL-9 and its correlation with eosinophils mucin-producing genes and proteins was observed in patients with EoE. Induced IL-9 may be responsible for the development of BE in patients with chronic EoE.

Oncogene Expression and Amplification in Barrett Adenocarcinoma

Oncogene activation by amplification and/or overexpression has been implicated in the development and progression of a number of malignancies. To better define the role of oncogene activation in adenocarcinomas arising in the setting of Barrett esophagus, we examined 44 resected Barrett adenocarcinomas for c-erb B-2, epidermal growth factor receptor (EGFR), c-myc, and cyclin DI gene amplification as well as c-erb B-2 and EGFR expression. DNA was extracted from formalin-fixed paraffin-embedded tissue and analyzed by differential polymerase chain reaction, a technique that permits semiquantitative analysis of gene dosage on archival material. Formalinfixed paraffin-embedded sections were stained with monoclonal antibodies directed against either the internal domain of c-erb B-2 or the extracellular domain of EGFR with a labeled streptavidin biotin technique. C-erb B-2 amplification was identified in three (7%) cases. A plasma membrane pattern of c-erb B-2 immunoreactivity in >50% of tumor cells correlated highly with c-erb B-2 amplification ( P=.00008). EGFR amplification was noted in 18% of cases and correlated highly with the intensity of EGFR immunoreactivity ( P=.0004). C-myc amplification was present in 18% of cases. No tumors showed cyclin DI amplification. Follow-up was available regarding 29 patients and showed decreased mean survival ( P=.029) in patients with strong EGFR immunoreactivity (5.8 months) versus those with weak or absent EGFR labeling (11.8 months), and a trend toward decreased one-year survival (P=.069) for patients with (17%) versus those without (52%) c-myc amplification. Our results indicate one or more selected oncogenes are amplified/overexpressed in some Barrett adenocarcinomas and that EGFR and c-erb B-2 overexpression correlates with amplification. Additionally, strong EGFR expression in tumor cells indicates a poorer prognosis.

Chemoprevention in Barrett's Esophagus: Current Status

Chemoprevention in Barrett's esophagus is currently applied only in research settings. Identifying pathways that can be targeted by safe, pharmaceutical or natural compounds is key to expanding the scope of chemoprevention. Defining meaningful surrogate markers of cancer progression is critical to test the efficacy of chemopreventive approaches. Combinatorial chemoprevention that targets multiple components of the same pathway or parallel pathways could reduce the risk and improve the efficacy of chemoprevention. Here we discuss the role of chemoprevention as an independent or an adjuvant management option in BE-associated esophageal adenocarcinoma.

Human epidermal growth factor receptor 2 overexpression and amplification in endoscopic biopsies and resection specimens in esophageal and junctional adenocarcinoma

Human epidermal growth factor receptor 2 (HER2) is overexpressed in a subset of esophageal adenocarcinomas. Frequently, biopsy material is used for evaluation of HER2 status. The aim of the study was to determine if HER2 expression in preoperative endoscopic biopsies is representative for the entire tumor. Preoperative endoscopic biopsies and matched resection specimens were collected from 75 patients who underwent esophagectomy for esophageal adenocarcinoma. Immunohistochemical staining (IHC) on HER2 and dual-color in situ hybridization (ISH) were performed. HER2 status was determined by following a clinical algorithm, first determining HER2 overexpression on immunohistochemistry and, when equivocal (2+), determining HER2 amplification on ISH. Seventy-one of 75 (95%) biopsies and 69/75 (92%) resection specimens could be analyzed due to technical failure. HER2 positivity was seen in 18/71 (25%) biopsies and in 15/69 (22%) resection specimens. Overall, HER2 status in the biopsy was concordant with HER2 status in the resection specimen in 94% of cases. Interobserver agreement on IHC scoring for all three observers was 83% in biopsies and 85% in resection specimens. HER2 positivity was detected in 22% of esophageal adenocarcinomas. Although interobserver agreement was moderate, HER2 status of a primary tumor can be reliably determined based on the endoscopically obtained pretreatment biopsy.

HER2 status in Barrett's esophagus & esophageal cancer: a meta analysis

BACKGROUND

The oncogenic potential of the Human Epidermal Growth Factor Receptor 2 (HER2) is well known in the context of breast cancer however; its relationship with the development of Barrett's Esophagus (BE) and Esophageal Cancer (EC) is unclear. The aim of this meta-analysis was to determine the overall prevalence and survival of HER2+ in BE & EC.

PATIENTS AND METHODS

Several databases were searched including article reference lists. Inclusion criteria required that studies measured HER2 positivity in subjects with BE or EC.

RESULTS

33 studies were included in the meta-analysis (10 BE & 23 EC studies). The prevalence of HER2+ was found to be 24% (95% CI: 15-36%) in BE and 26% (95% CI: 19-34%) in EC. Squamous cell carcinoma (SCC) had a higher ER of 32% (95% CI: 20-48%) in comparison with adenocarcinoma (ADC) with an ER of 21% (95% CI: 14-32%). Sub group analyses showed a high geographical variance, Asia was found to be the highest prevalent area with an ER 42% (95% CI: 22-64%). The difference in survival rate between groups HER2- & HER2+ was found to be 7 months.

CONCLUSIONS

Our results highlight a high prevalence of HER2+ in subjects with adenocarcinoma. HER2+ appears to decrease the survival time of EC patients.

Clinicopathological characteristics of human epidermal growth factor receptor 2-positive Barrett's adenocarcinoma

AIM: To compare the clinicopathological characteristics of human epidermal growth factor receptor 2 (HER2)-positive and HER2-negative Barrett’s adenocarcinoma in Japan.

METHODS: We performed immunohistochemical analysis of HER2 in 30 samples taken from patients with Barrett’s adenocarcinoma and dual color in situ hybridization in cases showing 2+ reactions. We compared the clinicopathological characteristics of HER2-positive and HER2-negative patients.

RESULTS: HER2 positivity was identified in 8 (27%) carcinoma samples. We found that HER2 expression was associated with p53 overexpression (100% vs 52.6% in pT1 tumor; 100% vs 54.5% in all stage tumor, P < 0.05) and protruding lesions at the early disease stage. There was no association between the mucin phenotype of the carcinomas and prognosis. HER2 expression and low clinical stage were unexpectedly different between Barrett’s adenocarcinoma patients and gastric cancer patients, but the macroscopic features may be associated with earlier diagnosis in these patients.

CONCLUSION: Our results suggest that HER2-positive Barrett’s adenocarcinomas are associated with p53 overexpression and lesion protrusion at the early disease stage.

Association of HER2/ErbB2 expression and gene amplification with pathologic features and prognosis in esophageal adenocarcinomas

PURPOSE

We examined the frequency, tumor characteristics, and prognostic impact of HER2 protein expression and gene amplification in patients with curatively resected esophageal adenocarcinoma (EAC).

EXPERIMENTAL DESIGN

HER2 expression was analyzed by immunohistochemistry (IHC) in surgical EAC specimens (n = 713). Gene amplification was examined by FISH in a large subset (n = 344). Most tumors were T3-4 (66%) or node positive (72%); 95% were located in the esophagus or gastroesophageal junction. No patient received neoadjuvant therapy. Cox models were used.

RESULTS

Overall, 17% of EACs were HER2 positive (i.e., IHC3(+) or IHC2(+) with amplification), with strong agreement between HER2 amplification (HER2/CEP17 ratio ≥2) and expression (κ = 0.83). HER2 positivity was significantly associated with lower tumor grade, less invasiveness, fewer malignant nodes, and the presence of adjacent Barrett's esophagus (BE). EACs with BE had higher odds of HER2 positivity than EACs without BE, independent of pathologic features [OR = 1.8 (95% CI: 1.1-2.8), P = 0.014]. Among all cases, HER2 positivity was significantly associated with disease-specific survival (DSS) in a manner that differed by the presence or absence of BE (P(interaction) = 0.0047). In EACs with BE, HER2 positivity was significantly associated with improved DSS [HR = 0.54 (95% CI: 0.35-0.84), P = 0.0065] and overall survival (P = 0.0022) independent of pathologic features, but was not prognostic among EACs without BE.

CONCLUSIONS

HER2 positivity was shown in 17% of resected EACs and associated with reduced tumor aggressiveness. EACs with BE had nearly twice the odds of being HER2 positive and, within this subgroup, HER2 positivity was independently associated with improved survival.

Regulation of ERBB2 receptor by t-DARPP mediates trastuzumab resistance in human esophageal adenocarcinoma

Esophageal adenocarcinoma (EAC) is an aggressive malignancy with a poor outcome. Although targeting ERBB2 with trastuzumab has been evaluated in clinical trials, the molecular mechanisms of trastuzumab resistance remain uncharacterized in EAC. The dopamine and cyclic AMP-regulated phosphoprotein of MR 32000 (DARPP-32), also known as PPP1R1B, is located together with ERBB2 at the 17q12-q21 amplicon. We evaluated the expression of a transcript variant of DARPP-32 (t-DARPP) and ERBB2 in 141 primary tumors and investigated the role of t-DARPP in trastuzumab resistance using OE19 and OE33 EAC cell models. Overexpression of t-DARPP mRNA was detected in two-thirds of tumors with a correlation between ERBB2 and t-DARPP overexpression levels (r = 0.58, P = 0.003). Cell viability and clonogenic survival assays showed that t-DARPP increased survival by 40% in response to trastuzumab (P < 0.01). The Annexin-V staining and Western blot analysis indicated that t-DARPP effectively abrogated trastuzumab-induced apoptosis, inhibited cleavage of caspase-3, and blocked trastuzumab-induced dephosphorylation of ERBB2 and AKT proteins. The knockdown of endogenous t-DARPP reversed these effects and sensitized cells to trastuzumab (P < 0.01). The cycloheximide-based protein degradation analysis indicated that t-DARPP extended the half-life of ERBB2, explaining the increase in the basal levels of ERBB2, p-ERBB2(Y1248), and p-AKT(S473). Coimmunoprecipitation and Western blot analysis showed that t-DARPP associated with ERBB2 in a protein complex, and interfered with trastuzumab binding to the ERBB2 receptor. Using EAC-xenografted mouse model, t-DARPP enhanced tumor growth and rendered tumors unresponsive to trastuzumab. This study establishes t-DARPP as a mediator of trastuzumab resistance and underscores its potential importance in clinical trials of EAC.

Relationship between HER-2 overexpression and brain metastasis in esophageal cancer patients

AIM: To study if HER-2 overexpression by locally advanced esophageal cancers increase the chance of brain metastasis following esophagectomy.

METHODS: We retrospectively reviewed the medical records of esophageal cancer patients who underwent esophagectomy at University of Iowa Hospitals and Clinics between 2000 and 2010. Data analyzed consisted of demographic and clinical variables. The brain metastasis tissue was assayed for HER-2 overexpression utilizing the FDA approved DAKO Hercept Test^®.

RESULTS: One hundred and forty two patients were reviewed. Median age was 64 years (36-86 years). Eighty eight patients (62%) received neoadjuvant chemoradiotherapy. Pathological complete and partial responses were achieved in 17 (19%) and 71 (81%) patients. Cancer relapsed in 43/142 (30%) patients. The brain was the first site of relapse in 9/43 patients (21%, 95% CI: 10%-36%). HER-2 immunohistochemistry testing of the brain metastasis tissue showed that 5/9 (56%) cases overexpressed HER-2 (3+ staining).

CONCLUSION: HER-2 overexpression might be associated with increased risk of brain metastasis in esophageal cancer patients following esophagectomy. Further studies will be required to validate this observation.

Risk factors for neoplastic progression in Barrett’s esophagus

Barrett’s esophagus (BE) confers a significant increased risk for development of esophageal adenocarcinoma (EAC), with the pathogenesis appearing to progress through a “metaplasia-dysplasia-carcinoma” (MDC) sequence. Many of the genetic insults driving this MDC sequence have recently been characterized, providing targets for candidate biomarkers with potential clinical utility to stratify risk in individual patients. Many clinical risk factors have been investigated, and associations with a variety of genetic, specific gastrointestinal and other modifiable factors have been proposed in the literature. This review summarizes the current understanding of the mechanisms involved in neoplastic progression of BE to EAC and critically appraises the relative roles and contributions of these putative risk factors from the published evidence currently available.

Epidermal growth factor receptor (EGFR) is overexpressed in high-grade dysplasia and adenocarcinoma of the esophagus and may represent a biomarker of histological progression in Barrett's esophagus (BE)

OBJECTIVES

The assessment of cancer risk in patients with Barrett's esophagus (BE) is currently fraught with difficulty. The current gold standard method of assessing cancer risk is histological assessment, with the appearance of high-grade dysplasia (HGD) as the key event monitored. Sampling error during endoscopy limits the usefulness of this approach, and there has been much recent interest in supplementing histological assessment with molecular markers, which may aid in patient stratification.

METHODS

No molecular marker has been yet validated to accurately correlate with esophageal histological progression. Here, we assessed the suitability of several membranous proteins as biomarkers by correlating their abundance with histological progression. In all, 107 patient samples, from 100 patients, were arranged on a tissue microarray (TMA) and represented the various stages of histological progression in BE. This TMA was probed with antibodies for eight receptor proteins (mostly membranous).

RESULTS

Epidermal growth factor receptor (EGFR) staining was found to be the most promising biomarker identified with clear increases in staining accompanying histological progression. Further, immunohistochemistry was performed using the full-tissue sections from BE, HGD, and adenocarcinoma tissues, which confirmed the stepwise increase in EGFR abundance. Using a robust H-score analysis, EGFR abundance was shown to increase 13-fold in the adenocarcinoma tissues compared to the BE tissues. EGFR was "overexpressed" in 35% of HGD specimens and 80% of adenocarcinoma specimens when using the H-score of the BE patients (plus 3 s.d.) as the threshold to define overexpression. EGFR staining was also noted to be higher in BE tissues adjacent to HGD/adenocarcinoma. Western blotting, although showing more EGFR protein in the adenocarcinomas compared to the BE tissue, was highly variable. EGFR overexpression was accompanied by aneuploidy (gain) of chromosome 7, plus amplification of the EGFR locus. Finally, the bile acid deoxycholic acid (DCA) (at neutral and acidic pH) and acid alone was capable of upregulating EGFR mRNA in vitro, and in the case of neutral pH DCA, this was NF-κB dependent.

CONCLUSIONS

EGFR is overexpressed during the histological progression in BE tissues and hence may be useful as a biomarker of histological progression. Furthermore, as EGFR is a membranous protein expressed on the luminal surface of the esophageal mucosa, it may also be a useful target for biopsy guidance during endoscopy.

Current diagnosis and future impact of micrometastases for therapeutic strategies in adenocarcinoma of the esophagus, gastric cardia, and upper gastric third

Esophageal and gastric cancers are aggressive neoplasms with a poor prognosis. Although postoperative mortality has declined and rates of complete resection have improved considerably, 5 year survival rates are still very low. Early metastatic relapse after complete resection of an apparently localized primary lesion indicates that disseminated tumor cells, undetectable by current methods, may already have been present at the time of surgery, even in patients with seemingly early tumor stages. Occult residual tumor disease is suggested when either bone marrow or lymph nodes from which tumor relapse may originate are affected by micrometastatic lesions undetectable by conventional histopathology. The presence of single tumor cells detected by immunohistological methods is increasingly regarded as a clinically relevant prognostic factor. The use of antibodies against tumor-associated targets enables detection of individual epithelial tumor cells in lymph nodes and in bone marrow in various tumor entities. The potential role and -benefit of an antibody-based treatment as a therapeutic target would be of particular interest in tumors with a notoriously poor prognosis such as esophageal cancer and cardia cancer.

Target-specific, histology-independent, randomized discontinuation study of lapatinib in patients with HER2-amplified solid tumors

BACKGROUND

To explore the activity of lapatinib with a novel trial design focused on the drug target rather than on histology.

METHODS

Patients with HER2 amplified gastro-esophageal, bladder, ovarian, or uterine tumors were enrolled into a double-blinded randomized discontinuation study of lapatinib 1,500 mg PO daily. The planned sample size was 250 patients with HER2 amplified tumors, with the goal of randomizing 100 patients with stable disease (SD) at week 12 to either lapatinib or placebo. Patients responding after 12 weeks continued on lapatinib; those who progressed were discontinued from study. The primary objectives were response rate after 12 weeks and the percentage of patients who remained progression free 12 weeks after randomization to placebo versus lapatinib. Secondary objectives were duration of response and determination of the incidence of HER2 amplification in multiple tumor types.

RESULTS

A total of 141 patients were screened and 32 patients with HER2 amplified tumors were enrolled. At week 12, 1 (3%) patient had a complete response, 9 (28%) had stable disease, 20 (63%) had progressive disease, and 2 (6%) were unknown. Only 7 patients with SD underwent randomization. The low response rate coupled with slow screening and enrollment led to early study closure.

CONCLUSIONS

Basing trial eligibility on the presence of a genetic target, versus histologic classification, is challenging. While HER2 amplifications appear to be prevalent in select non-breast tumors, lapatinib monotherapy is associated with modest activity. The target-specific histology-independent randomized discontinuation design still merits consideration for targets clearly implicated in "oncogene addiction".

Chromosomal abnormalities and novel disease-related regions in progression from Barrett's esophagus to esophageal adenocarcinoma

Barrett's esophagus (BE) is a metaplastic condition caused by chronic gastroesophageal reflux which represents an early step in the development of esophageal adenocarcinoma (EAC). Single-nucleotide polymorphism microarray (SNP-chip) analysis is a novel, precise, high-throughput approach to examine genomic alterations in neoplasia. Using 250K SNP-chips, we examined the neoplastic progression of BE to EAC, studying 11 matched sample sets: 6 sets of normal esophagus (NE), BE and EAC, 4 of NE and BE and 1 of NE and EAC. Six (60%) of 10 total BE samples and 4 (57%) of 7 total EAC samples exhibited 1 or more genomic abnormalities comprising deletions, duplications, amplifications and copy-number-neutral loss of heterozygosity (CNN-LOH). Several shared abnormalities were identified, including chromosome 9p CNN-LOH [2 BE samples (20%)], deletion of CDKN2A [4 BE samples (40%)] and amplification of 17q12-21.2 involving the ERBB2, RARA and TOP2A genes [3.1 Mb, 2 EAC (29%)]. Interestingly, 1 BE sample contained a homozygous deletion spanning 9p22.3-p22.2 (1.2 Mb): this region harbors only 1 known gene, basonuclin 2 (BNC2). Real-time PCR analysis confirmed the deletion of this gene and decreased the expression of BNC2 mRNA in the BE sample. Furthermore, transfection and stable expression of BNC2 caused growth arrest of OE33 EAC cells, suggesting that BNC2 functions as a tumor suppressor gene in the esophagus and that deletion of this gene occurs during the development of EAC. Thus, this SNP-chip analysis has identified several early cytogenetic events and novel candidate cancer-related genes that are potentially involved in the evolution of BE to EAC.

In vivo cancer biomarkers of esophageal neoplasia

The emergence of in vivo cancer biomarkers is promising tool for early detection, risk stratification, and therapeutic intervention in the esophagus, where adenocarcinoma is increasing at a rate that is faster than any other in industrialized nations. Exciting advances in target identification, probe development, and optical instrumentation are creating tremendous new opportunities for advancing techniques of molecular imaging. Progress in these areas is being made with small animal models of esophageal cancer using surgical approaches to induce reflux of acid and bile, and these findings are beginning to be evaluated in the clinic. Further identification of relevant targets, characterization of specific probes, and development of endoscopic imaging technologies are needed to further this direction in the field of molecular medicine. In the future, new methods that use in vivo cancer biomarkers for the early detection of neoplastic changes in the setting of Barrett's esophagus will become available.

Activation of growth factor receptors in esophageal cancer--implications for therapy

Esophageal cancer is a highly aggressive disease and is the seventh most common cause of cancer-related death in the western world. Worldwide, it ranks as the sixth most frequent cause of cancer death. Despite advances in surgical techniques and treatment, the prognosis of esophageal cancer remains poor, with very few long-term survivors. The need for novel strategies to detect esophageal cancer earlier and to improve current therapy is urgent. It is well established that growth factors and growth factor receptor-mediated signaling pathways are important components of the transformation process in many forms of cancer, including esophageal cancer. With the recent advances in drug development, there are emerging possibilities to use growth factor signal transduction pathways in targeted therapy. This review provides a summary of the role of growth factors and their receptors in esophageal cancer and discusses their potential roles as biomarkers and as targets in therapy.

Significance of HER2 low-level copy gain in Barrett's cancer: implications for fluorescence in situ hybridization testing in tissues

PURPOSE

HER2 may be a relevant biomarker in Barrett's cancer. We compared three HER2 laboratory methods, standard fluorescence in situ hybridization (FISH), image-based three-dimensional FISH in thick (16 microm) sections, and immunohistochemistry, to predict patient outcome.

EXPERIMENTAL DESIGN

Tissue microarray sections from 124 Barrett's cancer patients were analyzed by standard FISH on thin (4 microm) sections and by image-based three-dimensional FISH on thick (16 microm) sections for HER2 and chromosome-17, as well for p185(HER2) by immunohistochemistry. Correlations with clinical and follow-up data were examined.

RESULTS

Only three-dimensional FISH on thick (16 microm) sections revealed HER2 gene copy gain to be associated with increased disease-specific mortality (relative risk, 2.1; 95% confidence interval, 1.06-4.26; P = 0.033). In contrast, standard FISH on thin (4 microm) sections and immunohistochemistry failed to predict clinical outcome. Low-level gain of HER2 occurred frequently in Barrett's cancer (>or=2.5-4.0 HER2 copies, 59.7%; HER2-to-chromosome-17 ratio, >or=1.1-2.0; 61.2%) and defined a subpopulation for patient outcome as unfavorable as HER2 gene amplification [disease-free survival, P = 0.017 (HER2 copies)]. This low-level group was neither definable by standard FISH nor immunohistochemistry. No prognostic significance was found for chromosome-17 aneusomy.

CONCLUSIONS

Low-level copy gains of HER2 define a biologically distinct subpopulation of Barrett's cancer patients. Importantly, these subtle copy number changes are not reliably detected by standard FISH in thin (4 microm) tissue sections, highlighting a thus far unrecognized weakness in HER2 FISH testing. These results should be taken into account for accurate evaluation of biomarkers by FISH and for HER2 FISH testing in tissue sections.

Frequent homogeneous HER-2 amplification in primary and metastatic adenocarcinoma of the esophagus

HER-2 is the target for antibody based treatment of breast cancer (Herceptin). In order to evaluate the potential role of such a treatment in esophageal cancers, HER-2 amplification and overexpression was investigated in primary and metastatic cancers of the esophagus. A tissue microarray was constructed from 255 primary esophageal cancers (110 adenocarcinomas and 145 squamous cell carcinomas), 89 nodal and 33 distant metastases. Slides were analyzed by immunohistochemistry (HercepTest; DAKO) and fluorescence in situ hybridization (FISH; PathVysion; Vysis-Abbott) for HER-2 amplification and overexpression. Amplification was seen in 16/110 (15%) adenocarcinomas and in 7/145 (5%) squamous cell carcinomas. There was a strong association between HER-2 amplification and overexpression, especially in adenocarcinomas (P<0.0001, log rank). There was a 100% concordance of the HER-2 results in primary tumor and corresponding metastases in 84 analyzed pairs. Amplification was typically high-level with more than 10-15 HER-2 copies per tumor cell. Amplification was unrelated to survival, grading, pT, pN, pM or UICC stage. We conclude that esophageal adenocarcinomas belong to those cancer types with relevant frequency high-level HER-2 gene amplification clinical trials or individual case studies investigating the response of metastatic HER-2-positive esophageal cancers to Herceptin((R)) should be undertaken. The strong concordance of the HER-2 status in primary and metastatic cancers argues for a possible response of metastases from patients with HER-2-positive primary tumors to Herceptin.

Phase I/II study of trastuzumab, paclitaxel, cisplatin and radiation for locally advanced, HER2 overexpressing, esophageal adenocarcinoma

PURPOSE

To determine the overall survival for patients with locally advanced, HER2 overexpressing, esophageal adenocarcinoma receiving trastuzumab, paclitaxel, cisplatin, and radiation on a Phase I-II study.

METHODS AND MATERIALS

Patients with adenocarcinoma of the esophagus without distant organ metastases and 2+/3+ HER2 overexpression by immunohistochemistry (IHC) were eligible. All patients received cisplatin 25 mg/m2 and paclitaxel 50 mg/m2 weekly for 6 weeks with radiation therapy (RT) 50.4 Gy. Patients received trastuzumab at dose levels of 1, 1.5, or 2 mg/kg weekly for 5 weeks after an initial bolus of 2, 3, or 4 mg/kg.

RESULTS

Nineteen patients were entered: 7 (37%) had celiac adenopathy, and 7 (37%) had retroperitoneal, portal adenopathy, or scalene adenopathy. Fourteen of 19 patients (74%) had either 3+ HER2 expression by immunohistochemistry, or an increase in HER2 gene copy number by HER2 gene amplification or high polysomy by fluorescence in situ hybridization. The median survival of all patients was 24 months and the 2-year survival was 50%.

CONCLUSIONS

Assessment of the effect of trastuzumab in the treatment of patients with esophageal adenocarcinoma overexpressing HER2 is limited by the small number of patients in this study. Overall survival, however, was similar to prior studies without an increase in toxicity. Evaluation of HER2 status should be performed in future trials for patients with adenocarcinoma of the esophagus that investigate therapies targeting the HER family.

Her-2/neu in barrett esophagus: a comparative study between histology, immunohistochemistry, and fluorescence in situ hybridization

Her-2/neu is a protooncogene frequently overexpressed in breast cancer, recently found to be also overexpressed in carcinoma arising on Barrett esophagus (BE). Immunohistochemistry and fluorescence in situ hybridization (FISH) are conventionally used for Her-2 testing in carcinomas, but a single assay is not yet accepted as a "gold standard" in BE. To evaluate the correlation between histopathology variables and gene expression/amplification in the sequence BE-low grade dysplasia-high grade dysplasia-adenocarcinoma, fifty esophageal specimens from patients with a diagnosis of BE (21 BE, 4 low-grade dysplasia, 12 high-grade dysplasia, and 13 adenocarcinomas) were evaluated. Histopathologic evaluation was carried out using hematoxylin and eosin staining. Paraffin-embedded tissues were investigated for Her-2 by immunohistochemistry (HercepTest) and FISH. HercepTest was scored 0, 1+, 2+, and 3+ depending on the percentage (cut off 10%) of membrane staining, whereas gene assessment evaluated by FISH was based on the ratio between Her-2/neu and the 17 chromosome copy number. There was a positive correlation between gene amplification and protein overexpression. No case with HercepTest scoring 0 or 1+ displayed gene amplification, but this was present in 20% of cases scoring 2+ and in all cases scoring 3+. Her-2/neu amplification or overexpression was never observed in BE. Gene amplification and overexpression was observed in more than 50% of dysplasias and adenocarcinomas. Her-2/neu amplification/overexpression might be considered as a marker of progression from BE to dysplasia. FISH may represent a useful diagnostic tool to integrate the result of HercepTest for selecting patients for more targeted therapeutic approaches.

Molecular biology of esophageal cancer in the genomics era

The incidence of esophageal adenocarcinoma is rising in the United States and Western countries. Significant differences exist between esophageal adenocarcinoma and squamous cell carcinoma in the molecular mechanisms responsible for the tumorigenesis process. State-of-the-art techniques such as gene microarrays and proteomics will greatly aid in the development of new therapies targeting specific molecular pathways,ultimately leading to improved survival in patients who have esophageal cancer.

ERBB2 amplifications in esophageal adenocarcinoma

BACKGROUND

ERBB2 (v-erb-b2 erythroblastic leukemia viral oncogene homolog 2, Her-2-neu) gene amplification and overexpression has been reported in several types of cancer. The purpose of this study was to (1) determine the frequency of ERBB2 amplification (in comparison to other proto-oncogenes) in tumors from patients with esophageal adenocarcinoma, (2) characterize structural details of an ERBB2 amplicon in the esophageal adenocarcinoma cell line OE19 (contains a 100-fold ERBB2 amplification), and (3) test whether growth of the OE19 cell line is sensitive to the ERBB2 inhibitor trastuzumab (Herceptin; Genetech, Inc, San Francisco, CA).

METHODS

First, we determined the frequency, by Southern blotting techniques, of amplification of ERBB2 and 13 other proto-oncogenes in a panel of 25 esophageal adenocarcinoma tumors. Then, in a second panel of 10 tumor specimens, expression levels of the ERBB2 gene and of several other genes that flank ERBB2 on chromosome 17 were determined by microarray analysis. Next we characterized the ERBB2 amplicon in the esophageal adenocarcinoma cell line OE19 using cytogenetic methods and a Rec-A protein assisted restriction endonuclease mapping technique. Finally, an in vitro growth inhibition assay was used to measure the sensitivity of OE19 and OE33 cells to treatment with trastuzumab (humanized antibody to ERBB2).

RESULTS

ERBB2 was the most frequently amplified proto-oncogene among 25 esophageal adenocarcinoma tumors tested (greater than 10-fold amplification in 3 of 25 (12%) tumors tested). The OE19 cell line contains a 100-fold amplification of the ERBB2 gene, and highly expresses its messenger ribonucleic acid. Transcripts from genes that flank ERBB2 including GRB7, a protein linked to metastasis in esophageal cancer, also showed high levels of expression. In OE19 cells, the ERBB2 amplicon was localized to a homogeneously staining region of chromosome 14. Southern blots from the Rec-A protein assisted restriction endonuclease cleavage mapping experiments in OE19 showed a strong band of 210 kilobases in size, demonstrating that the main amplicon was a tandem repeat. In the in vitro growth inhibition assay, trastuzumab inhibited the OE19 and OE33 cells growth by 49% and 20%, respectively, at a saturating concentration of 20 microg/mL.

CONCLUSIONS

ERBB2 is the most frequently amplified proto-oncogene in esophageal adenocarcinoma among the genes that we tested. In the OE19 esophageal adenocarcinoma cell line, the ERBB2 amplicon is translocated onto chromosome 14, is amplified 100-fold at the deoxyribonucleic acid level, and is highly overexpressed at the messenger ribonucleic acid level. Finally, the growth of this cell line was inhibited by incubation with trastuzumab. These results demonstrate that a substantial number of esophageal adenocarcinomas have amplified copies of the ERBB2 gene, and that they may be responsive to ERBB2 targeted therapies such as trastuzumab.

The molecular biology of esophageal adenocarcinoma

BACKGROUND

Barrett's esophagus is an acquired metaplastic change that occurs in the distal esophagus secondary to chronic gastroesophageal reflux. This premalignant condition forms the most important risk factor for developing esophageal adenocarcinoma, which is an extremely aggressive tumor with a 5-year survival rate of less than 25%. Carcinomas that arise in the setting of Barrett's esophagus are thought to develop as part of the metaplasia-dysplasia-carcinoma sequence.

OBJECTIVE

To review the current knowledge on the genomic alterations involved in the development of Barrett's esophagus and its progression to dysplasia and/or cancer.

RESULTS

Several changes in gene structure, gene expression, and protein structure are associated with the progression of Barrett's esophagus to adenocarcinoma. Accumulation of these changes seems to be essential, rather than the exact sequence of these changes. Multiple molecular pathways are involved and interact with each other. Alterations in tumor suppressor genes, amongst which p53 and p16, are early events in the metaplasia-dysplasia-adenocarcinoma sequence, followed by loss of cell cycle checkpoints. Ongoing genomic instability leads to cumulative genetic errors and thereby the generation of multiple clones of transformed cells.

CONCLUSIONS

Within the multistep process of esophageal adenocarcinogenesis, to date no single molecular marker came forward able to predict who will and who will not develop cancer in the setting of Barrett's esophagus. Instead, panels of markers need to be developed in the future allowing to indicate disease progression. Identification of crucial molecular pathways involved in esophageal adenocarcinogenesis would ultimately improve therapy and facilitate development of new treatment strategies.

The pathogenesis of Barrett's esophagus

Significant progress has been made in clinicians' understanding of the molecular pathogenesis of BE, and the laboratory findings are beginning to lead to hypothesis-driven clinical studies; however, the following questions remain unanswered: (1) how can clinicians identify the persons most at risk for the development of esophageal adenocarcinoma, (2) what are the environmental gene interactions in esophageal carcinogenesis, and (3) can clinicians prevent the development of esophageal adenocarcinoma in the population at risk? As esophageal adenocarcinoma starts to reach epidemic proportions, further research in these areas is urgently required. With the advent of the genomic era and an explosion in studies in BE, significant progress can be made.

The role of receptor tyrosine kinase inhibition in treating gastrointestinal malignancy

Tyrosine kinase receptors are proteins that transduce the signal from many growth factor and cytokine ligands to produce intracellular responses. As such they can activate multiple signalling cascade pathways and influence cell division, migration and survival. Many show upregulation in certain malignancies, including those of the gastrointestinal tract, and are thought to play key roles in carcinogenesis. This makes them attractive targets for drug therapy and in recent years many inhibitors have been developed. This review discusses the current situation regarding the development of inhibitors with particular reference to the erbB family, the insulin-like growth factor receptor, the Met receptor, the receptor for vascular endothelial growth factor and the Kit receptor. The evidence will be related back to cancers of the gut lumen. Clinical effectiveness in this area seems to lie in using a combinatorial approach that inhibits multiple key signalling points, and the reasons for this will be discussed.

Gene amplification and protein overexpression of c-erb-b2 in Barrett carcinoma and its precursor lesions

We examined 39 samples of metaplastic specialized epithelium (SE), 27 of low-grade dysplasia (LGD), 27 of high-grade dysplasia (HGD), and 46 of adenocarcinoma (CA) derived from Barrett esophagus for c-erb-b2 gene amplification using differential polymerase chain reaction and for overexpression of c-erb-b2 protein using immunohistochemical analysis. Amplification of the c-erb-b2 gene was as follows: SE, 0.0%; LGD, 0.0%; HGD, 11.1%; and CA, 13.6%; and protein overexpression was as follows: SE, 0.0%; LGD, 7.4%; HGD, 18.5%; and CA, 21.7%. In 8 (89%) of 9 samples, c-erb-b2 gene amplification correlated with protein overexpression. The reverse was true in 8 (47%) of 17 samples: c-erb-b2 protein overexpression was proved with simultaneous gene amplification. Amplification of c-erb-b2 is a late event in the carcinogenesis of Barrett esophagus. In contrast, protein overexpression appears more often and earlier Besides gene amplification, other mechanisms to induce protein overexpression must exist.

Genetic pathways involved in the progression of Barrett's metaplasia to adenocarcinoma

BACKGROUND

The prediction of which patients with Barrett's metaplasia will develop cancer is difficult. Better genetic characterization of the condition may aid clinicians in devising more effective management and follow-up strategies.

METHODS

A review was undertaken of the accumulated genetic data relating to the progression of squamous epithelium to adenocarcinoma. The normal functions of a number of cancer-related genes are described and an explanation is given of how alterations in these genes interfere with normal cell processes and lead to cancer.

RESULTS AND CONCLUSION

The main genetic alterations accompanying the progression through dysplasia to adenocarcinoma were collated from 135 papers. The principal genetic changes implicated are the loss of p16 gene expression (by deletion or hypermethylation), the loss of p53 expression (by mutation and deletion), the increase in cyclin D1 expression, the induction of aneuploidy and the losses of the Rb, DCC and APC chromosomal loci.

Cellular and molecular mechanisms responsible for progression of Barrett's metaplasia to esophageal carcinoma

Barrett's metaplasia is found in approximately 12% to 18% of patients undergoing upper endoscopy for symptoms of reflux. Barrett's metaplasia is a premalignant condition and remains the number one risk factor for developing esophageal adenocarcinoma. There has been an increase in the incidence of esophageal adenocarcinoma in the past two decades, making it the most rapidly rising cancer in the United States and Western Europe. This article describes the progression from Barrett's metaplasia to esophageal adenocarcinoma and predictors for the development of adenocarcinoma in Barrett's metaplasia. Barrett's metaplasia represents a histological mosaic, with dysplastic tissue adjacent to non-dysplastic tissue. The histologic changes leading to adenocarcinoma are accompanied by alterations at the molecular level, including the accumulation of gene mutations and changes in gene expression. The determination of the molecular events that occur in the transition from normal esophageal squamous mucosa to dysplasia and to esophageal adenocarcinoma have lead to a better understanding of the process of the transformation to adenocarcinoma. This knowledge will lead to better biomarkers to diagnose and assess cancer risk.

Expression of CD44v5 and -v6 in Barrett's carcinoma is not increased compared to that in nondysplastic Barrett's mucosa

Barrett's adenocarcinoma currently shows the highest increase in the incidence of all malignant tumors. Reliable molecular markers to identify Barrett's patients at risk are still missing. Our own results demonstrate that the expression of CD44v6 correlates with the development of dysplasia in colorectal neoplasms. Therefore, we examined the expression of CD44 variants v5 and v6 in normal esophageal mucosa, non-dysplastic Barrett's mucosa, and Barrett's carcinoma. mRNA from biopsy specimens of patients with Barrett's esophagus (n = 19) or Barrett's carcinoma (n = 15) and patients without esophageal diseases (controls; n = 9) were extracted and used as templates for cDNA synthesis. CD44 variants were detected by RT-PCR with primers hybridizing with CD44 sequences up- and downstream of variable exons. CD44v6 expression was found in 36 of 56 biopsy specimens (64%) of non-dysplastic Barrett's mucosa, in 100% of squamous epithelium, and in none of the gastric mucosa specimens. Eleven of 15 specimens (73%) of Barrett's carcinoma tested positive for v6 expression. The identification of v5 expression did not give additional information. There was no correlation between CD44v5 or -v6 expression and staging or grading of the tumors. Expression of CD44v5 and -v6 seems to be independent of the development of cancer in Barrett's mucosa.

Role of molecular biology in the follow-up of patients who have Barrett's esophagus

At present, the follow-up of patients who have Barrett's esophagus (BE) should occur within the setting of an endoscopic biopsy surveillance program and with the frequency of surveillance as proposed by the American College of Gastroenterology. In the future, patients who have BE will be further stratified according to their risk for progression to invasive carcinoma. This stratification will permit the development of more rational surveillance programs. Models that incorporate epidemiologic risk factors, reflux symptoms, and endoscopic and histologic findings will likely include panels of biomarkers for further stratification of patients as low, intermediate, or high risk. Therefore, the challenge over the next decade will be to define the role of molecular markers in endoscopic surveillance strategies and to identify additional clinically relevant molecular markers for prognosis as intermediate markers for chemoprevention and as molecular targets for novel gene therapies.

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.

Her-2/neu gene amplification, elevated mRNA expression, and protein overexpression in the metaplasia-dysplasia-adenocarcinoma sequence of Barrett's esophagus

SUMMARY

The importance of alterations of the Her-2/neu oncogene in the tumorigenesis of Barrett's adenocarcinoma (BCA) is discussed controversially. In the present study, we evaluated for the first time the Her-2/neu status in the metaplasia-dysplasia-adenocarcinoma sequence of BCA simultaneously at the DNA, mRNA, and protein level using resection specimens of 25 patients. The locus-specific Her-2/neu gene status was quantified by performing fluorescence in situ hybridization, and information about the ploidy status of chromosome 17 was obtained. Tissue sections from the same areas were used for quantitative RT-PCR (TaqMan RT-PCR) of laser-microdissected tumor cells and for immunohistochemistry to quantify Her-2/neu mRNA and oncoprotein expression. Her-2/neu gene amplification was observed in 35% of BCA, and all of these samples showed strong overexpression of both mRNA and oncoprotein. A polysomy 17 without Her-2/neu gene amplification was observed in 52% of BCA, showing a normal or moderately elevated mRNA expression and no or weak immunopositivity. From 13 areas of high-grade dysplasia (HGD) we found four to be amplified for the Her-2/neu locus, whereas five showed a polysomy 17. All four samples of HGD areas with Her-2/neu gene amplification displayed mRNA and strong oncoprotein overexpression; however, lower mRNA levels were seen than in the amplified BCA areas. None of the samples with low-grade dysplasia (LGD) showed a locus-specific Her-2/neu amplification, but polysomy 17 was present in four of eight cases. No changes were detected in BCA-associated intestinal metaplasia and squamous epithelium. In summary, only a locus-specific Her-2/neu gene amplification was associated with strong mRNA overexpression and strong membranous Her-2/neu immunostaining in BCA and HGD. A chromosome 17 polysomy, as found in the majority of BCA, led to no or weak mRNA overexpression and no or weak immunopositivity. In the metaplasia-dysplasia-adenocarcinoma sequence, a chromosome 17 polysomy without Her-2/neu gene amplification was already present in LGD. This may be a result of an early polyploidization, preceding the later genetic events, such as Her-2/neu gene amplification in HGD and BCA.

Molecular biology of Barrett's adenocarcinoma

OBJECTIVE

To review the current knowledge on the genetic alterations involved in the development and progression of Barrett's esophagus-associated neoplastic lesions.

SUMMARY BACKGROUND DATA

Barrett's esophagus (BE) is a premalignant condition in which the normal squamous epithelium of the esophagus is replaced by metaplastic columnar epithelium. BE predisposes patients to the development of esophageal adenocarcinoma. Endoscopic surveillance can detect esophageal adenocarcinomas when they are early and curable, but most of the adenocarcinomas are detected at an advanced stage. Despite advances in multimodal therapy, the prognosis for invasive esophageal adenocarcinoma is poor. A better understanding of the molecular evolution of the Barrett's metaplasia to dysplasia to adenocarcinoma sequence may allow improved diagnosis, therapy, and prognosis.

METHODS

The authors reviewed data from the published literature to address what is known about the molecular changes thought to be important in the pathogenesis of BE-associated neoplastic lesions.

RESULTS

The progression of Barrett's metaplasia to adenocarcinoma is associated with several changes in gene structure, gene expression, and protein structure. Some of the molecular alterations already showed promise as markers for early cancer detection or prognostication. Among these, alterations in the p53 and p16 genes and cell cycle abnormalities or aneuploidy appear to be the most important and well-characterized molecular changes. However, the exact sequence of events is not known, and probably multiple molecular pathways interact and are involved in the progression of BE to adenocarcinoma.

CONCLUSIONS

Further research into the molecular biology of BE-associated adenocarcinoma will enhance our understanding of the genetic events critical for the initiation and progression of Barrett's adenocarcinoma, leading to more effective surveillance and treatment.

Endoscopic mapping and surrogate markers for better surveillance in Barrett esophagus. A study of 700 biopsy specimens

Surveillance methods in Barrett esophagus (BE) using light microscopic examination of random biopsy specimens may miss focal dysplasia. In addition, dysplastic foci identified initially may not be relocated subsequently, making chemoprevention studies difficult. By using a special gastroscope, systematic mapping (4-quadrant biopsy specimens at 1-cm intervals) was performed in 22 patients (33 total mappings yielding 700 biopsy specimens). H&E, immunohistochemistry, and DNA ploidy analysis were performed. c-erbB-2 and positive Ki-67 were detected only in dysplastic sites; thus, their detection did not precede morphologically identifiable dysplasia. On the other hand, aneuploidy and p53 were detected in dysplastic and nondysplastic areas. p53 was correlated with dysplasia, and S-phase narrowly missed correlation, while aneuploidy was not correlated. PCNA and bcl-2 were ubiquitous, limiting their usefulness. On second maps, epithelial type was reidentified with 81% accuracy. A significant correlation was found between p53 and dysplasia. Sites of dysplasia and abnormal biomarkers could be relocated accurately by using endoscopic mapping. Therefore, mapping combined with biomarker studies may provide better surveillance and serve as a useful technique in chemoprevention studies.

Molecular genetic changes in metastatic primary Barrett's adenocarcinoma and related lymph node metastases: comparison with nonmetastatic Barrett's adenocarcinoma

Lymph node metastasis is one of the strongest negative prognostic factors for patients with Barrett's adenocarcinoma (BCA). However, despite the importance of the metastatic process in BCA, the molecular basis of it remains poorly understood. To search for cytogenetic events associated with metastasis in regional or distant lymph nodes in BCA, we investigated 8 primary BCA and their lymph node metastases and compared them with 18 nonmetastatic BCA. In metastatic primary BCA, we observed significantly more DNA gains on 3q (P = .013), 17q (P = .019), and 22q (P = .021) compared with nonmetastatic primary BCA. No statistically significant correlation could be observed between DNA copy number changes and the histopathologic stage, grade, or survival (P > .05). The most frequent alteration observed only in lymph node metastases but not in the related primary tumor was loss of 2q (5 of 8). Coamplification of 7p and chromosome 17 was found in 6 of 8 lymph node metastases. A comparison of DNA copy number changes between primary tumors and their corresponding metastases indicated a high degree of genetic heterogeneity. Fluorescence in situ hybridization analysis demonstrated the involvement of the Her-2/neu gene in primary BCA and its related lymph node metastases. Each of the investigated primary tumors and related lymph node metastases also showed striking heterogeneity with respect to Her-2/neu, with several areas displaying different levels of amplification. In summary, our data indicate that DNA copy number changes on 2q, 3q, 7p, 17q, and 22q may be involved in the metastatic process in BCA. Furthermore, the striking genetic heterogeneity that we found between primary BCA and its lymph node metastases may underlie BCA's poor responsiveness to therapy and could help explain why prognostic biomarkers measured exclusively in primary tumors give an incomplete view of the biologic potential of BCA.

Intestinal and pancreatic metaplasia at the esophagogastric junction in patients without Barrett's esophagus

OBJECTIVES

A distinctive type of columnar epithelium with intestinal metaplasia is considered diagnostic for Barrett's esophagus. The neoplastic potential of pancreatic metaplasia at the esophagogastric junction is unknown. The aims of the present study were: 1) to characterize both forms of metaplasia at the esophagogastric junction, and to estimate their prevalence; 2) to investigate c-erbB-2 expression and K-ras mutations in pancreatic metaplasia; and 3) to study the relationship between metaplasia, inflammatory changes in the cardiac mucosa, and presence of H. pylori.

METHODS

A total of 76 esophagogastrectomy specimens of patients with a normally located squamocolumnar junction, were investigated immunohistochemically. K-ras mutations were evaluated using PCR.

RESULTS

Intestinal metaplasia in the cardia was found in 12% of patients: six complete-type, and three incomplete-type. Pancreatic metaplasia was demonstrated in 14% of patients, and neither c-erbB-2 expression nor K-ras mutations were found. Intestinal and pancreatic metaplasia were associated with mucosal inflammation. In contrast to generalized gastritis, isolated "carditis" was not associated with H. pylori infection.

CONCLUSIONS

When intestinal metaplasia occurs in a biopsy from the esophagogastric junction, it is not necessarily a marker for Barrett's esophagus. No indication was found that pancreatic metaplasia has neoplastic potential. Both forms of metaplasia reflect mucosal inflammation. Carditis may be a distinct inflammatory condition of the gastric mucosa that is not related to H. pylori infection.

HER-2/neu gene amplification by FISH predicts poor survival in Barrett's esophagus-associated adenocarcinoma

The HER-2/neu oncogene is localized to chromosome 17q and shares significant homology with the epidermal growth factor receptor. HER-2/neu protein overexpression has been associated with poor prognosis in a variety of tumors, but its significance in Barrett's esophagus-associated adenocarcinoma (BEAd) is unknown. Therefore, the aim of this study was to evaluate the prevalence and prognostic value of HER-2/neu gene amplification by fluorescence in situ hybridization (FISH) in 63 cases of BEAd. Routinely processed tissue sections from resection specimens of 63 patients with BEAd (M/F ratio, 10:1; mean age, 63 years) were assayed for HER-2/neu gene amplification by FISH using the Ventana unique sequence probe (Ventana Medical Systems, Inc, Tuscon, AZ). FISH results were correlated with the pathological features of the tumors and with patient survival. Clinical follow-up data were available for 54 patients (mean follow-up, 31 months [range, 1 to 152 months]). The HER-2/ neu gene was amplified in 12 of 63 (19%) cases. The presence of HER-2/neu gene amplification showed a trend toward a correlation with depth of tumor invasion (P = .07), lymph node metastasis (P = .13), and pathological stage (P = .14), but did not correlate with any of the other pathological features, such as degree of differentiation or tumor size. On both univariate and multivariate analysis, HER-2/neu gene amplification was associated with shortened survival (P = .03). HER-2/neu oncogene amplification, as determined by FISH, correlates with shortened patient survival and independently predicts poor outcome in patients with BEAd.

Complete regression of Barrett's esophagus with heat probe thermocoagulation: mid-term results

BACKGROUND

Barrett's esophagus is a premalignant condition. It has been reported that several methods of endoscopic ablation in combination with acid suppression result in replacement of specialized columnar epithelium by squamous epithelium. The aim of this study was to assess whether ablation of Barrett's mucosa by means of heat probe and acid suppression restores normal esophageal mucosa.

METHODS

Thirteen patients with Barrett's epithelium but not dysplasia were enrolled in the study. Helicobacter pylori was eradicated when discovered. Thermal energy was applied using a heat probe (pulses of 5 to 10 joules). Four-quadrant biopsies were obtained at 1 to 2 cm intervals 1 to 3 months after the last treatment session. All patients continuously took omeprazole, 40 mg/day.

RESULTS

Macroscopically, ablation of Barrett's mucosa was achieved in all patients after 1 to 5 sessions. Three of the 13 patients had residual specialized columnar epithelium beneath the restored mucosa but not overexpression of p53 and c-erbB-2. During follow-up (6 to 36 months) two patients in whom the length of Barrett's mucosa was greater than 2.5 cm relapsed after omeprazole discontinuation, whereas another two with length of less than 2.5 cm did not. One patient with residual Barrett's islands developed low-grade dysplasia.

CONCLUSIONS

Heat probe is an effective and inexpensive method for Barrett's ablation. Islands of residual specialized columnar epithelium were found in 23% of patients. The length of Barrett's epithelium determines relapse after omeprazole discontinuation. (Gastrointest Endosc 1999;50:165-72).

Prognostic value of Laurén classification and c-erbB-2 oncogene overexpression in adenocarcinoma of the esophagus and gastroesophageal junction

BACKGROUND

The prognostic value of the Laurén classification and of c-erbB-2 oncogene overexpression has been described for gastric cancer. The aim of this study was to investigate the clinical significance of these factors in adenocarcinoma of the esophagus and/or gastroesophageal junction (GEJ).

METHODS

Forty-one adenocarcinomas of the esophagus and/or GEJ were reviewed for tumor stage, lymph node status, Laurén classification, and c-erbB-2 overexpression, as assessed by immunohistochemical analysis.

RESULTS

According to the Laurén classification, tumors were classified as intestinal-, mixed-, or diffuse-type (54%, 32%, and 15%, respectively). Diffuse-type tumors were associated with a significantly worse prognosis than were intestinal-type tumors (P = .018; log-rank test). The prognostic value of the Laurén classification was independent of stage (P = .048; Cox regression model). Overexpression of c-erbB-2 was detected in 24% of the tumors and was present exclusively in intestinal-type tumors and in intestinal-type areas of mixed-type tumors. Ten of the 30 stage III/IV tumors (33%) were c-erbB-2-positive, whereas none of the 11 stage I/II tumors (0%) overexpressed the oncogene product (P = .04; Fisher exact test). The prognostic value of c-erbB-2 overexpression was not independent of stage (P = .7; Cox regression model).

CONCLUSIONS

(1) The Laurén classification is an independent prognostic factor in adenocarcinoma of the esophagus and GEJ. (2) c-erbB-2 overexpression is limited to (areas of) intestinal-type tumors, indicating that intestinal- and diffuse-type tumors differ oncogenetically. (3) c-erbB-2 overexpression is associated with the stage of disease, indicating that it is a late event during tumor progression.

The histopathology and biologic prognostic factors of Barrett's esophagus: a review

In Barrett's esophagus, stratified squamous mucosa of the lower third of the esophagus is replaced by columnar mucosa, as a complication of chronic gastroesophageal reflux. The presence of Barrett's esophagus appears to be a major factor in the progression to adenocarcinoma of the lower third of the esophagus. Therefore it is crucial to identify the subset of patients at risk for the development of adenocarcinoma. Dysplasia is an important histologic feature to evaluate because it identifies those patients who require follow-up. The diagnosis of biopsies with lesser degrees of abnormalities, however, makes microscopic evaluation less helpful in identifying patients who need more frequent endoscopic biopsy surveillance. DNA ploidy and the use of monoclonal antibodies, such as suppressor gene product p53, oncogene cerbB-2, and Ki-67, have added dramatically to our understanding of the biology of Barrett's metaplasia and have given us objective indicators to predict the presence of an increased risk of developing cancer.

The molecular basis for carcinogenesis in metaplastic columnar-lined esophagus

A wide variety of biologic events and mechanisms appear to have roles in the development and progression of Barrett's esophagus-associated neoplastic lesions. Figure 5 is a schematic depiction of these events. This is known as an infernogram (named after Dante's Inferno) (S. Kern, unpublished presentations, 1996). Events at the bottom rings of the inferno are high-frequency mutations; nearer to the top of the inferno are the less common events. The next several years promise many further discoveries of not only high-frequency and low-frequency events, but also their application. Some of the molecular alterations already studied show promise as markers for early cancer detection or prognostication. Eventually, applications of these discoveries should yield new and more effective means of preventing and treating the deadly complications of this troublesome premalignant condition.

Expression of c-erbB-2 protein in keratinocytes of oral mucosal lichen planus and subsequent squamous cell carcinoma

Oral mucosal lichen planus (OMLP) is a well recognized mucosal disease with unknown etiology. Considerable controversy exists as to whether OMLP is intrinsically premalignant, or if the disorder facilitates the development of oral mucosal squamous cell carcinoma (OMSCC) by external factors. The aim of the present study was to investigate the expression of c-erbB-2 protein in the keratinocytes of initial biopsies or oral mucosal disorders diagnosed as OMLP with no evidence of epithelial dysplasia, and to compare the results with the expression of c-erbB-2 protein in subsequent biopsies obtained from the same patients. These results were compared with the findings from control groups (patients with dysplasia with no evidence of OMLP, patients with OMSCC with no evidence of OMLP and normal oral mucosa). The expression of the c-erbB-2 protein was evaluated by immunohistochemical staining of the gene product with the avidin-biotin-complex method using paraffin-embedded tissues sections. Five of the initial biopsies from patients with OMLP expressed the c-erbB-2 protein and one did not. None of the OMLP cases that subsequently showed evidence of dysplasia expressed the c-erbB-2 protein, and of the three OMSCC specimens from the patients with OMLP, two were negative and one expressed c-erbB-2 protein. The specimens from the control groups all expressed the c-erbB-2 protein. The results indicated the probability of the absence of c-erbB-2 staining being an indication of a potential for neoplastic transformation in OMLP with dysplastic changes.