Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0024623 (gastric cancer)
 36,219 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The human epidermal growth factor receptor-2 gene (HER-2) encodes for a membrane-bound tyrosine kinase (Her-2), which is overexpressed in various human cancers. Her-2-targeted therapy has recently been shown to be beneficial for patients with advanced gastric cancer. Her-2 protein expression was investigated in 341 esophageal carcinomas [152 squamous cell carcinomas (SCC), 189 adenocarcinomas (AC)], 39 cases of Barrett mucosa, and 11 cases of squamous cell dysplasia. HER-2 gene amplification was assessed by colorimetric in-situ hybridization. Positive Her-2 status was found in 15.3% of ACs and 3.9% of SCCs. Positive Her-2-status was more common in dysplastic Barrett mucosas compared with nondysplastic ones (P=0.04). In 26% of the patients with ACs who had received neoadjuvant chemotherapy (n=39), the Her-2 status of pretherapeutic biopsies was different compared with subsequent surgical specimens. There was no statistically significant correlation between Her-2 status and patients' survival. Although Her-2 overexpression is rare in SCCs, it is found in 15.3% of ACs, where amplification of HER-2 gene and overexpression of Her-2 protein seem to be early events in carcinogenesis. The evaluation of Her-2 status in tumor biopsies and in particular in the context with possible alterations after neoadjuvant treatment can potentially lead to false Her-2-staging. Although Her-2-overexpression in esophageal cancer seems to have no influence on patients' survival, these subtypes of esophageal ACs have to be considered as targets for an anti-Her-2 therapy.
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PMID:Expression of Her-2 in carcinomas of the esophagus. 2110 94

Despite ongoing advances in the treatment of gastroesophageal cancer, prognosis remains poor. The best promise to improve this poor survival is provided by new targeted agents. Of these, human epidermal growth factor receptor 2 (HER2) is currently in the spotlight. In this review, we provide an overview of recent developments in HER2 testing and results of clinical trials targeting HER2 in gastroesophageal adenocarcinoma. Based on the encouraging ToGA trial findings it is now expected that routine HER2 testing will be included in the diagnostic work-up of patients with advanced gastric cancer. With regard to this testing, overexpression of the HER2 protein seems to possess the best predictive properties. However, HER2 immunohistochemistry (IHC) is subject to assay and interobserver variability, so standardization and internal and external proficiency testing is an absolute prerequisite, especially as the IHC scoring system in gastric cancer is different from that of breast cancer. Further study is needed to investigate the clinical meaning of the significant heterogeneity observed in both gene amplification and protein overexpression in gastroesophageal cancer. Highly effective therapies for gastroesophageal cancer can only be accomplished by a multi-targeted approach, considering crosstalk between pathways and continuing to optimize chemotherapy.
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PMID:Her-2/neu testing and therapy in gastroesophageal adenocarcinoma. 2118 13

Cyclooxygenase-2 (COX-2) plays an important role in tumorigenesis through prostaglandin E(2) (PGE(2)) biosynthesis. It has been shown by in vitro studies that PGE(2) signaling transactivates epidermal growth factor receptor (EGFR) through an intracellular mechanism. However, the mechanisms underlying PGE(2)-induced EGFR activation in in vivo tumors are still not fully understood. We previously constructed transgenic mice that develop gastric tumors caused by oncogenic activation and PGE(2) pathway induction. Importantly, expression of EGFR ligands, epiregulin, amphiregulin, heparin-binding EGF-like growth factor, and betacellulin, as well as a disintegrin and metalloproteinases (ADAMs), ADAM8, ADAM9, ADAM10, and ADAM17 were significantly increased in the mouse gastric tumors in a PGE(2) pathway-dependent manner. These ADAMs can activate EGFR by ectodomain shedding of EGFR ligands. Notably, the extensive induction of EGFR ligands and ADAMs was suppressed by inhibition of the PGE(2) receptor EP4. Moreover, EP4 signaling induced expression of amphiregulin and epiregulin in activated macrophages, whereas EP4 pathway was required for basal expression of epiregulin in gastric epithelial cells. In contrast, ADAMs were not induced directly by PGE(2) in these cells, suggesting indirect mechanism possibly through PGE(2)-associated inflammatory responses. These results suggest that PGE(2) signaling through EP4 activates EGFR in gastric tumors through global induction of EGFR ligands and ADAMs in several cell types either by direct or indirect mechanism. Importantly, gastric tumorigenesis of the transgenic mice was significantly suppressed by combination treatment with EGFR and COX-2 inhibitors. Therefore, it is possible that inhibition of both COX-2/PGE(2) and EGFR pathways represents an effective strategy for preventing gastric cancer.
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PMID:Activation of epidermal growth factor receptor signaling by the prostaglandin E(2) receptor EP4 pathway during gastric tumorigenesis. 2120 91

Despite recent improvements in surgical techniques and chemotherapy treatments, locally advanced/metastatic gastroesophageal junction (GEJ) and gastric cancer (GC) are still associated with poor clinical outcome. However, increased understanding of molecular mechanisms underlying carcinogenesis and its implementation in the treatment of breast, colon, lung, and other cancers in recent years have spurred focus on the development and incorporation of targeted agents in current therapeutic options for this difficult-to-treat disease. Such agents have the ability to target a variety of cancer relevant targets, including epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) and its receptor. In this review, we describe the current status of targeted therapies in the treatment of advanced GC and GEJ cancer, focusing on pre-clinical and clinical data available on monoclonal antibodies and tyrosine kinase inhibitors acting in these pathways, including completed and ongoing phase III studies.
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PMID:Advanced gastric cancer (GC) and cancer of the gastro-oesophageal junction (GEJ): focus on targeted therapies. 2125 46

PURPOSE : Treatment effects of advanced gastric cancer (AGC) are unsatisfactory, and novel therapeutic approaches are much needed. The epidermal growth factor receptor (EGFR) monoclonal antibody cetuximab inhibits the growth of several human cancer cells but has been tested rarely for the treatment of GC. The synergy between cetuximab and irinotecan has been reported in colorectal cancer, but the mechanisms are still not fully clarified. Consequently, we hypothesized cetuximab/irinotecan combination should enhance the antitumor activity of irinotecan in GC cells. METHODS : The in vitro antiproliferative, pro-apoptotic, cell cycle arrest effects and induction of senescence were examined in SGC-7901 and MKN-45 GC cell lines. The effects of cetuximab or irinotecan as single agents or the combination on the expression of p53, p16, and EGFR signaling pathways were also studied. RESULTS : The study revealed that cetuximab alone did not show any antiproliferative, pro-apoptotic, cell cycle arrest or cellular senescence effect on GC cells but when combined with irinotecan synergistically inhibits GC cell proliferation and induces apoptosis and G2/M phase arrest. Irinotecan increases phosphorylation of EGFR, MAPK, and AKT and decreases the expression of P27(Kip1), which could be all abrogated by its combination with cetuximab. The combination could also inhibit the expression of Cyclin D1 and phosphorylated mTOR while had no impact on p53, p16, PTEN, and HIF-1alpha. CONCLUSIONS : Cetuximab enhances the activities of irinotecan on GC cells via the downregulation of the EGFR pathway upregulated by irinotecan. Combination therapy with cetuximab and irinotecan, a novel therapeutic approach, warrants further study in GC.
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PMID:Cetuximab enhances the activities of irinotecan on gastric cancer cell lines through downregulating the EGFR pathway upregulated by irinotecan. 2128 18

A 57-year-old female with advanced gastric cancer was referred to our hospital. She underwent neoadjuvant chemotherapy with S-1 plus cisplatin followed by curative gastrectomy. Weekly paclitaxel and combination chemotherapy with irinotecan plus cisplatin were administered for lymph node recurrence, but the tumor progressed. Since the human epidermal growth factor receptor 2 status of her gastric cancer specimen was strongly positive, docetaxel plus trastuzumab was administered for three cycles. However, the lymph node metastasis appeared to enlarge and abdominal pain worsened. Therefore, combination chemotherapy with lapatinib and weekly trastuzumab was initiated. A computed tomographic scan after 3 months of treatment showed stable disease. Although dose reduction of lapatinib was necessary due to Grade 3 diarrhea, the patient has continued this treatment on an outpatient basis without signs of disease progression for 8 months after initiation. In this case, trastuzumab plus lapatinib resulted in durable stable disease, despite the appearance of progression during prior chemotherapy with trastuzumab.
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PMID:Lapatinib plus trastuzumab for a patient with heavily pre-treated gastric cancer that progressed after trastuzumab. 2133 37

Gastric cancer is a prevalent and deadly disease with poor survival of patients with metastatic disease. Although distinct epidemiologic and histologic subtypes of gastric cancer can be identified, the disease is commonly grouped together as a single disease and treated as on entity. However, as molecularly targeted therapies are applied to gastric cancer, this disease heterogeneity has increasingly become clinically relevant. In this review, we summarize the development of agents targeting the human epidermal growth factor receptor (HER) family HER 2 and epidermal growth factor receptor EGFR), vascular endothelial growth factor (VEGF), MET and regulators of cell cycle as they are integrated into therapeutic studies with the goal of improving therapeutic options for this disease. We summarize the rationale for targeting these pathways, in the context of an emerging paradigm of gastric cancer as three unique disease subtypes. The results of the clinical trials evaluating these agents, including completed and ongoing evaluations, are summarized.
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PMID:Molecularly targeted therapies in advanced gastric cancer. 2137 72

Despite recent advances in chemotherapy, the prognosis for patients with advanced gastric cancer (GC) or gastroesophageal junction cancer remains poor. Human epidermal growth factor receptor 2 (HER2) is a novel target for biologic therapy in metastatic GC. We analyzed the association between HER2 overexpression and the clinicopathologic characteristics of advanced GC. Formalin-fixed, paraffin-embedded tumor samples were collected from patients with stage III or to IV (M(0)) GC who subsequently underwent curative surgery followed by adjuvant chemotherapy with 5-fluorouracil and cisplatin. All the samples were analyzed for HER2 status by immunohistochemistry (IHC) and fluorescence in situ hybridization. Of 142 samples analyzed, 7.1% scored IHC 2+ and 8.6% scored IHC 3+, whereas 9.3% were HER2-amplified. Of HER2-amplified cases, 76.9% (10/13) scored IHC 3+, showing the correlation between HER2 amplification and overexpression (P=0.01). HER2 IHC 3+ cases were more common in the intestinal-type tumors compared with diffuse-type tumors (16.7% vs. 5.1%, respectively; P=0.049), and a nonsignificant trend was observed using fluorescence in situ hybridization (14.3% vs. 9.2%, respectively; P=0.399). HER2 gene amplification was more frequent in stage IV (M(0)) than stage III disease (15.4% vs. 4.0%, respectively; P=0.037). Interestingly, HER2-amplified disease was more common than nonamplified disease in patients with nodal stage 3 tumors (76.9% vs. 38.6%, respectively; P=0.009); a similar pattern was observed using IHC. HER2 overexpression correlated with nodal stage, and a lymph node ratio greater than 0.5 was more common in HER2-amplified tumors than HER2-nonamplified tumors (69.2% vs. 43.3%, respectively; P=0.086). These findings suggest that further investigations of adjuvant therapy with HER2-targeted therapy for advanced GC are warranted.
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PMID:Clinicopathologic characteristics of patients with stage III/IV (M(0)) advanced gastric cancer, according to HER2 status assessed by immunohistochemistry and fluorescence in situ hybridization. 2153 92

Patients with metastatic gastric cancer have a poor outcome. The development of new combinations of chemotherapy has led to steady but only modest gains in overall survival with largest effects reported with two- and three-drug regimens. Trastuzumab, a fully humanized monoclonal antibody directed at the human epidermal growth factor receptor-2 (HER2), has been found to improve response rate and survival in patients with advanced gastric cancer. This update will review the role of HER2 and summarize therapeutic advances in the use of trastuzumab in advanced gastric cancer.
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PMID:New developments in the treatment of metastatic gastric cancer: focus on trastuzumab. 2155 12

Advanced or metastatic gastric cancer constitutes the majority of patients in clinical practice. In North America, about 70% of cases are advanced or metastatic when diagnosed, which is higher than the 50% reported in Japan. This difference in presentation is reflected in 5-year overall survival, which is about 20% in North America and 40%-60% in Japan. Despite numerous efforts of randomized studies on advanced gastric cancer, no globally accepted standard regimen has yet been established. Systemic chemotherapy provides palliation and prolongs survival, but the prognosis remains poor. Several monotherapies and combined regimens are currently available and vary around the world. Additionally, several molecular targeting agents are under evaluation in international randomized studies. Human epidermal growth factor receptor-2 (HER-2) is overexpressed or amplified in approximately 22% of patients with gastric cancer. Trastuzumab, a recombinant humanized anti-HER-2 monoclonal antibody, is the first biological therapy that has showed a survival improvement by nearly three months (reduced risk of death by 26%). Therefore, trastuzumab in combination with cisplatin is a reasonable treatment option for patients with advanced gastric cancer who are HER-2 positive. This paper will focus on trastuzumab, its chemical and pharmacological characteristics, and the relevant efficacy, safety, and tolerability studies.
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PMID:Critical appraisal of trastuzumab in treatment of advanced stomach cancer. 2155 17


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