The prognostic impact of epidermal growth factor receptor in patients with metastatic gastric cancer

Targeting CD24 in Cancer Immunotherapy

Immunotherapy is a hot area in cancer treatment, and one of the keys to this therapy is the identification of the right tumour-associated or tumour-specific antigen. Cluster of differentiation 24 (CD24) is an emerging tumour-associated antigen that is commonly and highly expressed in various tumours. In addition, CD24 is associated with several cancer-related signalling pathways and closely interacts with other molecules and immune cells to influence tumour progression. Monoclonal antibodies, antibody-drug conjugates (ADCs), chimeric antigen receptor (CAR) T-cell therapy, and CAR-NK cell therapy are currently available for the treatment of CD24. In this review, we summarise the existing therapeutic approaches and possible future directions targeting CD24.

Evodiamine Inhibits Gastric Cancer Cell Proliferation via PTEN-Mediated EGF/PI3K Signaling Pathway

Aims

In this study, the pharmacological effects and potential molecular mechanisms of evodiamine in treating gastric cancer (GC) were investigated.

Methods

GC cells lines of AGS and BGC-823 were treated with evodiamine at various concentrations for different times (24, 48, and 72 h). Inhibition of the proliferation of AGS and BGC-823 cells was assessed using a CCK-8 assay. The morphology of gastric cancer cells was detected by high-content screening (HCS). The apoptosis-inducing effect of evodiamine on AGS and BGC-823 cells was detected by flow cytometric analysis. Cell migration and invasion were detected by Transwell assay. The relative mRNA and protein expression levels of PTEN-mediated EGF/PI3K signaling pathways were investigated via RT-qPCR or western blotting, respectively.

Results

Evodiamine substantially inhibited AGS and BGC-823 cells proliferation in a dose- and time-dependent manner. Flow cytometric analysis revealed that evodiamine could induce apoptosis of AGS and BGC-823 cells in a dose-dependent manner. In addition, evodiamine inhibited AGS and BGC-823 cell migration and invasion. Mechanistically, the results demonstrated that evodiamine promoted the relative mRNA and protein expression of PTEN and decreased expression of EGF, EGFR, PI3K, AKT, p-AKT, and mTOR. Most importantly, evodiamine could effectively increase the mRNA and protein expression of PTEN and decrease the protein expression of EGF/PI3K pathway, indicating that evodiamine downregulated EGF/PI3K through the activation of PTEN pathway.

Conclusion

Evodiamine inhibited the directional migration and invasion of GC cells by inhibiting PTEN-mediated EGF/PI3K signaling pathway. These findings revealed that evodiamine might serve as a potential candidate for the treatment or prevention of GC.

Gallic acid suppresses colon cancer proliferation by inhibiting SRC and EGFR phosphorylation

The aim of the present study was to investigate the effects of gallic acid (GA) on the proliferation and apoptosis of colon cancer cells and to further clarify the mechanism of GA function associated with SRC and EGFR phosphorylation. HCT116 and HT29 cells were treated with different concentrations of GA for 24 h. Cell proliferation and apoptosis were analyzed using plate clone formation and flow cytometry assays, respectively. In addition, the expression of apoptosis-related proteins was examined by western blotting. Furthermore, the level of STAT3, AKT, SRC and EGFR phosphorylation was analyzed by western blotting and immunofluorescence. Subsequently, the SRC inhibitor PP2 and the EGFR inhibitor gefitinib were used to analyze the GA-associated mechanisms. In addition, a xenograft tumor model was established to confirm the effects of GA in vivo. The results indicated that GA inhibited cell proliferation and promoted cell apoptosis by upregulating the ratio of cleaved caspase-3/pro-caspase-3 and cleaved caspase-9/pro-caspase-9. Concurrently, GA decreased the level of phosphorylated (p)-SRC, p-EGFR, p-AKT and p-STAT3. Following treatment with PP2 and gefitinib in both cancer cell lines and animal model, GA was demonstrated to inhibit EGFR and SRC phosphorylation to downregulate STAT3 and AKT phosphorylation. In vivo, GA prevented tumor growth, promoted tumor apoptosis and decreased the level of p-SRC, p-EGFR, p-STAT3 and p-AKT. In conclusion, GA was indicated to suppress colon cancer proliferation by inhibiting SRC and EGFR phosphorylation.

Differential prognostic implications of gastric adenocarcinoma based on Lauren's classification: a Surveillance, Epidemiology, and End Results (SEER)-based cohort study

Background

Our study aims to analyze the association between Lauren's classification and gastric adenocarcinoma prognosis using comprehensive statistical analyses.

Methods

According to the selection criteria, patients were included from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate Cox regression, propensity score matching, and a multivariate competing risk model were used to investigate the association between Lauren's classification and prognosis. Subgroup analysis was used to investigate the role of confounding factors on the association between Lauren types and prognosis.

Results

After exclusion, a total of 20,218 patients from the SEER database were included, with 14,374 intestinal types and 5,844 diffuse types. The univariate Cox regression analysis revealed that the diffuse type had a poorer cancer-specific survival (CSS) rate [hazard ratio (HR), 1.44; 95% confidence interval (CI), 1.38-1.50]. After adjusting for confounding variables, the diffuse type also showed a higher risk of cancer-specific death (HR, 1.20; 95% CI, 1.15-1.20). Sensitivity analysis showed that after propensity score matching, the diffuse type had a poorer CSS rate (HR, 1.23; 95% CI, 1.10-1.36), and the competing risk model further validated these results [subdistribution HR (SHR), 1.32; 95% CI, 1.23-1.41]. Moreover, subgroup analysis demonstrated stable results in the subgroups, except for patients with T1 stage (HR, 1.06; 95% CI, 0.87-1.28) and a tumor size <2 cm (HR, 1.00; 95% CI, 0.83-1.21).

Conclusions

Diffuse-type gastric adenocarcinoma had an overall poorer prognosis compared to the intestinal type. However, in patients with T1 stage and tumor size <2 cm, the diffuse type had a comparable survival rate with the intestinal type.

A cohort study and meta-analysis of the evidence for consideration of Lauren subtype when prescribing adjuvant or palliative chemotherapy for gastric cancer

Background

The association between the survival or efficacy of chemotherapy and the Lauren subtype of gastric cancer (GC) remains unclear. We aimed to clarify whether patients with different Lauren subtypes have different survival after treatment with systemic chemotherapy: intestinal gastric cancer (IGC) patients survived better than patients with mixed type gastric cancer (MGC) or diffuse gastric cancer (DGC) after treatment with systemic chemotherapy.

Patients & methods

Relevant studies for the meta-analysis were identified through searching Pubmed, Embase, Cochrane and Ovid up to March 2020. We also included our own prospectively collected cohort of patients that were followed over a 10-year period. Sub-group and sensitivity analyses were also performed.

Results

In our prospective cohort, the overall survival (OS) of IGC patients receiving systemic chemotherapy (chemoIGC) [median OS 5.01 years, interquartile range (IQR) 2.63-6.71] was significantly higher than that of DGC patients receiving the same chemotherapy (chemoDGC) (median OS 1.33 years, IQR 0.78-3.33, p = 0.0001). After adjusting for age, gender and cancer stage, there was a significant difference in OS in patients treated with chemotherapy based on the Lauren classification of GC {hazard ratio (HR) for OS of the IGC versus DGC 0.33, [95% confidence interval (CI), 0.17-0.65; p < 0.001]}. In the IGC patients, the adjusted HR associated with chemotherapy was 0.26 (95% CI, 0.12-0.56; p = 0.001), whereas the association was 0.64 (95% CI, 0.30-1.33; p = 0.23) in the DGC patient group.In our meta-analysis, 33 studies comprising 10,246 patients treated with systemic chemotherapy (chemoIGC n = 4888, chemoDGC n = 5358) met all the selection criteria. While we accounted for much of the heterogeneity in these studies, we found that chemoIGC patients showed significantly improved OS [HR, 0.76 (95% CI, 0.71-0.82); p < 0.00001] when compared with similarly treated chemoDGC patients.

Conclusion

Our results support the consideration of Lauren subtype when prescribing systemic chemotherapy for GC, particularly for MGC or DGC, which may not benefit from chemotherapy. Lauren classification should be considered to stratify chemotherapy regimens to GC patients in future clinical trials, with particular relevance to MGC or DGC, which is more difficult to treat with current regimens.

Epidermal Growth Factor Receptor Family and its Role in Gastric Cancer

Despite the gradual decrease in incidence, gastric cancer is still the third leading cause of cancer death worldwide. Although chemotherapy enhances overall survival and quality of life in advanced disease, the median overall survival is < 12 months. In recent years, the human epidermal growth factor receptor (ErbB) family has been extensively investigated in gastric cancer. The ErbB family is composed of four closely-related members: ErbB-1 (HER1 or epidermal growth factor receptor, EGFR), ErbB-2 (HER2), ErbB-3 (HER3), and ErbB-4 (HER4), all of which play a critical role in regulating cell growth, proliferation and migration of tumors. It is well known that gastric cancer overexpresses HER in a heterogeneous pattern, especially EGFR, and HER2. HER3 is another important member of the ErbB family that preferentially activates the phosphatidylinositol 3-kinase (PI3K) pathway. Furthermore, its heterodimerization with HER2 seems fundamental for steering HER2-overexpressing breast cancer tumor growth. Less is known about the impact of HER4 on gastric cancer. Improved survival from the use of trastuzumab has paved the way for ErbB receptor family-targeted treatments in gastric cancer. However, unlike trastuzumab, ErbB receptor-targeted drugs have not consistently maintained the encouraging results obtained in preclinical and early clinical trials. This may be attributable to the intrinsic heterogeneity of gastric cancer and/or to the lack of standardized test quality for established biomarkers used to evaluate these biological targets. This review presents an overview of the most recent clinical studies on agents targeting the ErbB family in gastric cancer.

Prognostic importance of PTEN, EGFR, HER-2, and IGF-1R in gastric cancer patients treated with postoperative chemoradiation

Background/aim

This study aimed to describe the prognostic importance of epidermal growth factor (EGFR), phosphatase and tensin homolog (PTEN), human EGF receptor-2 (HER-2), and insulin-like growth factor 1 receptor (IGF-1R) in gastric cancer patients treated with postoperative chemoradiation therapy.

Materials and methods

Sixty-nine patients treated with adjuvant chemoradiation therapy were retrospectively evaluated. Tumor samples were stained immunohistochemically.

Results

All patients were treated with 3D conformal radiation therapy with concomitant and adjuvant chemotherapy. Perineural invasion (PNI) (P = 0.042), prechemoradiation therapy albumin levels below 3.5 mg/dL (P = 0.011), and EGFR positivity (P = 0.008) had negative effects on overall survival (OS). The median OS was 26 months for patients with PNI (+), 34.9 months for those with PNI (–), 19.5 months for those with albumin levels below 3.5 mg/dL, and 33.2 months for those with albumin levels above 3.5 mg/dL. IGF-1R (+) (P = 0.035) and history of cigarette smoking (P = 0.033) were observed to have a statistically significantly negative effect on disease-free survival (DFS). The median DFS was 29.2 months for IGF-1R (+) patients, 37.9 months for those with IGF-1R (-), and 26.3 and 40.59 months for smokers and nonsmokers, respectively.

Conclusion

IGF-1R and EGFR may be used for patient selection in future prospective studies that evaluate the prognostic importance of these receptors.

Relationship between EGFR expression and subcellular localization with cancer development and clinical outcome

Epidermal growth factor receptor (EGFR) as a prevalent oncogene regulates proliferation, apoptosis and differentiation and thereby contributes to carcinogenesis. Even though, the documentation on its clinical relevance is surprisingly heterogeneous in the scientific literature. Here, we systematically investigated the correlation of mRNA to survival time and pathological parameters by analyzing 30 datasets in silico. Furthermore, the prognostic value of membrane-bound, cytoplasmic (mcEGFR) and nuclear expression (nEGFR) of EGFR was experimentally analyzed by immunohistochemical staining of 502 biopsies from 27 tumor types. We found that protein expression of EGFR showed better prognostic efficiency compared to mRNA, and that mcEGFR expression was positively correlated with nEGFR expression (p < 0.001). Unexpectedly, both mcEGFR and nEGFR expression were associated with low T stage (p < 0.001 and p = 0.004; respectively). Moreover, positive mcEGFR was significantly related to high differentiation (p = 0.027). No significant correlation was found with any other pathological parameters. Collectively, our results imply that the oncogenic function of EGFR may be more related to nascent stages of carcinogenesis than to advanced and progressive tumors, which may as well explain at least partially the occurrence of secondary resistance against EGFR-directed therapy.

Stimulation of natural killer cells with rhCD137 ligand enhances tumor-targeting antibody efficacy in gastric cancer

Although many anticancer agents for gastric cancer have been developed, the prognosis for many patients remains poor. Recently, costimulatory immune molecules that reactivate antitumor immune responses by utilizing the host immune system have attracted attention as new therapeutic strategies. CD137 is a costimulatory molecule that reportedly potentiates the antitumor activity of tumor-targeting monoclonal antibodies (mAbs) by enhancing antibody-dependent cellular cytotoxicity. However, it remains unclear whether CD137 stimulates tumor-regulatory activity in gastric cancer. In this study, we investigated the antitumor effects of CD137 stimulation on gastric cancer cells administered tumor-targeting mAbs. Our results showed that human natural killer (NK) cells were activated by expressing CD137 after encountering trastuzumab-coated gastric cancer cells, and that stimulation of activated NK cells in the presence of trastuzumab and recombinant human CD137 ligand (rhCD137L) enhanced cytotoxicity and release of cytokines (IFN-γ, TNF, granzyme A, or granzyme B) as compared with activated NK cells with trastuzumab alone (p < 0.05). By combination treatment with rhCD137L, similar effects were obtained regarding cancer cell cytotoxicity in the presence of cetuximab (p < 0.01). Moreover, we revealed that CD137 expression was dependent upon the affinity between the Fc portion of the antibodies and FcγRIIIa of NK cells based on results indicating that human IgG1 and IgG3 subclasses enhanced CD137 expression (p < 0.001). These results confirmed that FcγRIIIA polymorphisms (158 V/V) enhanced CD137 expression to a greater degree than 158 F polymorphisms (p = 0.014). Our results suggested that CD137 stimulation could promote the effects of tumor-targeting mAbs in gastric cancer, and that further investigation of antibody binding affinity and in vivo activities might improve therapeutic strategies related to the treatment of gastric cancer patients.

CT textural analysis of gastric cancer: correlations with immunohistochemical biomarkers

To investigate the ability of CT texture analysis to assess and predict the expression statuses of E-cadherin, Ki67, VEGFR2 and EGFR in gastric cancers, the enhanced CT images of 139 patients with gastric cancer were retrospectively reviewed. The region of interest was manually drawn along the margin of the lesion on the largest slice in the arterial and venous phases, which yielded a series of texture parameters. Our results showed that the standard deviation, width, entropy, entropy (H), correlation and contrast from the arterial and venous phases were significantly correlated with the E-cadherin expression level in gastric cancers (all P < 0.05). The skewness from the arterial phase and the mean and autocorrelation from the venous phase were negatively correlated with the Ki67 expression level in gastric cancers (all P < 0.05). The width, entropy and contrast from the venous phase were positively correlated with the VEGFR2 expression level in gastric cancers (all P < 0.05). No significant correlation was found between the texture features and EGFR expression level. CT texture analysis, which had areas under the receiver operating characteristic curve (AUCs) ranging from 0.612 to 0.715, holds promise in predicting E-cadherin, Ki67 and VEGFR2 expression levels in gastric cancers.

Nomograms predicting survival of patients with unresectable or metastatic gastric cancer who receive combination cytotoxic chemotherapy as first-line treatment

BACKGROUND

Some clinicopathological variables are known to influence the survival of patients with advanced gastric cancer. A comprehensive model based on these factors is needed for prediction of an individual's survival and appropriate patient counseling.

METHODS

A nomogram for predicting 1-year survival in patients with advanced gastric cancer in the palliative chemotherapy setting was developed using clinicopathological data from 949 patients with unresectable or metastatic gastric cancer who had received first-line doublet cytotoxic chemotherapy from 2001 to 2006 at the National Cancer Center, Korea (Baseline Nomogram). For 836 patients whose initial response to chemotherapy is known, another nomogram (ChemoResponse-based Nomogram) was constructed using the response to chemotherapy as additional variable. Nomogram performance in terms of discrimination and calibration ability was evaluated using the C statistic and Hosmer-Lemeshow-type χ ² statistics.

RESULTS

Two different nomograms were developed and subjected to internal validation. The baseline nomogram incorporated 13 baseline clinicopathological variables, whereas the chemoresponse-based nomogram was composed of 11 variables including initial response to chemotherapy. Internal validation revealed good performance of the two nomograms in discrimination: C statistics = 0.656 (95% confidence interval, 0.628-0.673) for the baseline and 0.718 (95% confidence interval, 0.694-0.741) for the chemoresponse-based nomogram, which showed significantly better discrimination performance than the baseline nomogram (Z statistics = 3.74, p < 0.01).

CONCLUSION

This study suggests that individual 1-year survival probability of patients receiving first-line doublet cytotoxic chemotherapy for advanced gastric cancer can be reliably predicted by a nomogram-based method incorporating clinicopathological variables and initial response to chemotherapy.

Gene mutations in stool from gastric and colorectal neoplasia patients by next-generation sequencing

AIM

To study cancer hotspot mutations by next-generation sequencing (NGS) in stool DNA from patients with different gastrointestinal tract (GIT) neoplasms.

METHODS

Stool samples were collected from 87 Finnish patients diagnosed with various gastric and colorectal neoplasms, including benign tumors, and from 14 healthy controls. DNA was isolated from stools by using the PSP^® Spin Stool DNA Plus Kit. For each sample, 20 ng of DNA was used to construct sequencing libraries using the Ion AmpliSeq Cancer Hotspot Panel v2 or Ion AmpliSeq Colon and Lung Cancer panel v2. Sequencing was performed on Ion PGM. Torrent Suite Software v.5.2.2 was used for variant calling and data analysis.

RESULTS

NGS was successful in assaying 72 GIT samples and 13 healthy controls, with success rates of the assay being 78% for stomach neoplasia and 87% for colorectal tumors. In stool specimens from patients with gastric neoplasia, five hotspot mutations were found in APC, CDKN2A and EGFR genes, in addition to seven novel mutations. From colorectal patients, 20 mutations were detected in AKT1, APC, ERBB2, FBXW7, KIT, KRAS, NRAS, SMARCB1, SMO, STK11 and TP53. Healthy controls did not exhibit any hotspot mutations, except for two novel ones. APC and TP53 were the most frequently mutated genes in colorectal neoplasms, with five mutations, followed by KRAS with two mutations. APC was the most commonly mutated gene in stools of patients with premalignant/benign GIT lesions.

CONCLUSION

Our results show that in addition to colorectal neoplasms, mutations can also be assayed from stool specimens of patients with gastric neoplasms.

The Prognostic Significance of c-MET and EGFR Overexpression in Resected Gastric Adenocarcinomas

OBJECTIVES

Epidermal growth factor receptor (EGFR) and c-MET are tyrosine kinase growth factor receptors implicated in gastric cancer (GC), and their pathways appear to be interdependent. The aim of this study was to investigate the prognostic value of EGFR and c-MET protein overexpression by immunohistochemistry in Canadian patients with resected GC and correlate it with clinicopathologic characteristics and overall survival (OS).

MATERIALS AND METHODS

Tissue microarray blocks were constructed from 120 resected GCs stained with EGFR and c-MET and scored semiquantitatively (0 to 3+). Each receptor's expression was compared with clinicopathologic characteristics and survival. Descriptive statistics, Kaplan-Meyer, and Cox regression were used for statistical analyses.

RESULTS

Of the 113 interpretable cases, overexpression of EGFR and c-MET was noted in 17 (15%) and 65 (57%), respectively; coexpression of EGFR and c-MET was observed in 12 (10%) of GC. EGFR and c-MET overexpression correlated with poor OS: median 13 versus 30 months in EGFR positive versus negative GC (hazard ratio [HR]=1.67, P=0.11); 27 versus 49 months in c-MET positive versus negative GC (HR=1.17, P=0.49), respectively. GC coexpressing EGFR and c-MET was significantly correlated with poor survival: 12 versus 29 months in double-positive versus rest of tumors both in univariate (HR=2.62, P=0.003) and multivariate analyses (HR=2.58, P=0.01).

CONCLUSIONS

This study describes the prevalence and prognostic value of EGFR and c-MET in a Canadian population of patients undergoing curative intent resection for GC. Both c-MET and EGFR overexpression trended toward poor OS, but only the group with EGFR+/c-MET+ GC reached statistical significance on multivariate analysis.

Does the discrepancy in histologic differentiation between a forceps biopsy and an endoscopic specimen necessitate additional surgery in early gastric cancer?

AIM

To investigate the clinicopathological variables in early gastric cancer (EGC) patients in relation to differentiation discrepancy.

METHODS

The data of 265 specimens from 240 patients with EGC, who had undergone radical operation at Hallym University Sacred Heart Hospital from 2010 to 2015, were retrospectively analyzed. We evaluated clinical, endoscopic, and histopathological data according to histological discrepancy.

RESULTS

Clinically significant discrepancy rate showed the difference in differentiated type (well and moderately differentiated) and undifferentiated type (poorly differentiated and signet ring cell) between endoscopic biopsies and postoperative specimens was 9.4% (25/265). There were no differences in tumor location, size, gross pattern, and number of biopsies. Specimens having histological discrepancy showed more submucosal invasion (72.0% vs 49.6%, P = 0.033) and lymph node involvement (24.0% vs 7.9%, P = 0.009) than specimens having non-discrepancy. The rate of a positive epidermal growth factor receptor status was higher in specimens having discrepancy than in specimens having non-discrepancy (81.0% vs 55.4%, P = 0.035).

CONCLUSION

The discordance of histologic differentiation is associated with higher submucosal invasion and lymph node metastases in EGC. Patients have histological discrepancy may require additional surgical treatments.

Clinicopathologic and prognostic significance of human epidermal growth factor receptor in patients with gastric cancer: An updated meta-analysis

Purpose

The aim of this update meta-analysis was to clarify the clinicopathologic and prognostic significance of human epidermal growth factor receptor(EGFR) expression in gastric cancer patients.

Experimental Design

Several electronic databases were searched from January 1970 to May 2016. The odds ratio (OR) was calculated to assess the association between EGFR expression and pathological parameters. The hazard ratio (HR) and 95% CI were calculated to explore the relationship between EGFR expression and overall survival.

Results

Finally 7229 patients with gastric cancer from 25 eligible studies were included in the present meta analysis. High EGFR expression was found to be significantly related with tumor differentiation (OR=1.96, 95%CI: 1.14-3.34, Z=2.43, P=0.015), lymph node metastasis (OR=2.20, 95% CI: 1.63-2.96, Z=5.17, P=0.001), and tumor stage (OR=2.13, 95% CI: 1.35-3.36, Z=3.25, P=0.001). However, high EGFR expression was not significantly associated with invasion depth (OR=2.09, 95% CI: 0.4-11.05, Z=0.87, P=0.385). The pooled HR suggested that high EGFR expression was significantly correlated with overall survival (HR=1.19, 95% CI 1.04-1.37, Z=2.44, P=0.015).

Conclusions

The present meta-analysis demonstrated that high EGFR expression significantly predicts poor prognosis, suggesting that high EGFR expression may serve as a predictive biomarker for poor prognosis in patients with gastric cancer.

Second-line treatments: moving towards an opportunity to improve survival in advanced gastric cancer?

Gastric cancer is the third leading cause of cancer-related death globally with approximately 723 000 deaths every year. Most patients present with advanced unresectable or metastatic disease, only amenable to palliative systemic treatment and a median survival uncommonly exceeding 12 months. Over the last years, the efficacy of chemotherapy combination has plateaued and the introduction of the anti-human epidermal growth factor receptor 2 trastuzumab has resulted in a limited survival gain in the upfront setting. After this positive experience, first-line treatment with new targeted therapies failed to improve the outcome of advanced gastric cancer. On the contrary, second-line options, including monochemotherapy with taxanes or irinotecan and the anti-vascular endothelial growth factor receptor 2 ramucirumab, either alone or combined with paclitaxel, opened new therapeutic rooms for an ever-increasing number of patients who maintain an acceptable performance status across multiple lines. This article provides an updated overview on the current management of advanced gastric cancer and discusses how the different treatment options available may be best combined to favourably impact the outcome of patients following the logic of a treatment strategy.

Prognostic value of diffuse versus intestinal histotype in patients with gastric cancer: a systematic review and meta-analysis

BACKGROUND

There are two distinct types of gastric carcinoma (GC), intestinal, more frequently sporadic and linked to environmental factors, and diffuse (undifferentiated) that is highly metastatic and characterized by rapid disease progression and a poor prognosis. However, there are many conflicting data in the literature concerning the association between histology and prognosis in GC. This meta-analysis was performed to provide demonstration if histology according to Lauren classification is associated with different prognosis in patients with GC.

METHODS

We searched PubMed, the Cochrane Library, SCOPUS, Web of Science, CINAHL, and EMBASE for all eligible studies. The combined hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) in terms of overall survival (OS) were evaluated.

RESULTS

A total of 73 published studies including 61,468 patients with GC were included in this meta-analysis. Our analysis indicates that GC patients with diffuse-type histology have a worst prognosis than those with intestinal subgroup in all studies (HR 1.23; 95% CI, 1.17-1.29; P<0.0001), in both loco-regional confined (HR 1.21; 95% CI, 1.12-1.30; P<0.0001) and advanced disease (HR 1.25; 95% CI, 1.046-1.50; P=0.014), in Asiatic (HR 1.2; 95% CI, 1.14-1.27; P<0.0001) and Western patients (HR 1.3; 95% CI, 1.19-1.41; P<0.0001), and in those not exposed (HR 1.15; 95% CI, 1.07-1.24; P<0.0001) or exposed (HR 1.27; 95% CI, 1.17-1.37; P<0.0001) to (neo)adjuvant therapy.

CONCLUSIONS

Our results indicated that histology might be a useful prognostic marker for both early and advanced GC patients, with intestinal-type associated with a better outcome. This information could be used for stratification purpose in future clinical trials.

RANKL/RANK pathway abrogates cetuximab sensitivity in gastric cancer cells via activation of EGFR and c-Src

Overexpression of EGFR is commonly seen in gastric cancer (GC). However, patients with GC show resistance to anti-EGFR treatments. RAS mutations are rare in GC and cannot explain de novo resistance to EGFR treatments. Therefore, it is particularly important to explore the mechanisms of resistance to anti-EGFR treatments. The RANKL activates the EGFR pathway in osteoclasts, and the RANK is expressed in gastric carcinoma. Whether the RANKL/RANK pathway has an effect on the EGFR pathway in GC remains unknown. Expressions of EGFR and RANK in GC tissues were detected using immunohistochemical staining. Nineteen patients (28%) showed high-level RANKL expression, and 33 patients (48%) showed high-level RANK expression. There was a positive correlation between expression of EGFR and RANK (P<0.001). In an in vitro study, RANKL induced activation of the EGFR pathway and further abrogated cetuximab sensitivity in GC cells. Knockdown of RANK or use of the RANKL inhibitor enhanced cetuximab effect by decreasing RANKL-induced EGFR activation. Furthermore, we showed that c-SRC mediated the EGFR activation induced by the RANKL/RANK pathway and that c-SRC inhibitor reversed the suppression of RANKL on the effect of cetuximab. In conclusion, our results suggest that in GC cells, the RANKL/RANK pathway activates the EGFR pathway and thereby causes resistance to anti-EGFR treatments.

EGF-Induced VEGF Exerts a PI3K-Dependent Positive Feedback on ERK and AKT through VEGFR2 in Hematological In Vitro Models

EGFR and VEGFR pathways play major roles in solid tumor growth and progression, however, little is known about these pathways in haematological tumors. This study investigated the crosstalk between EGFR and VEGFR2 signaling in two hematological in vitro models: THP1, a human monocytic leukemia, and Raji, a Burkitt's lymphoma, cell lines. Results showed that both cell lines express EGFR and VEGFR2 and responded to EGF stimulation by activating EGFR, triggering VEGF production and phosphorylating ERK, AKT, and p38 very early, with a peak of expression at 10-20min. Blocking EGFR using Tyrphostin resulted in inhibiting EGFR induced activation of ERK, AKT, and p38. In addition, EGF stimulation caused a significant and immediate increase, within 1min, in pVEGFR2 in both cell lines, which peaked at ~5-10 min after treatment. Selective inhibition of VEGFR2 by DMH4, anti-VEGFR2 antibody or siRNA diminished EGF-induced pAKT and pERK, indicating a positive feedback exerted by EGFR-induced VEGF. Similarly, the specific PI3K inhibitor LY294002, suppressed AKT and ERK phosphorylation showing that VEGF feedback is PI3K-dependent. On the other hand, phosphorylation of p38, initiated by EGFR and independent of VEGF feedback, was diminished using PLC inhibitor U73122. Moreover, measurement of intracellular [Ca2+] and ROS following VEGFR2 inhibition and EGF treatment proved that VEGFR2 is not implicated in EGF-induced Ca2+ release whereas it boosts EGF-induced ROS production. Furthermore, a significant decrease in pAKT, pERK and p-p38 was shown following the addition of the ROS inhibitor NAC. These results contribute to the understanding of the crosstalk between EGFR and VEGFR in haematological malignancies and their possible combined blockade in therapy.

Rab11-FIP2 promotes the metastasis of gastric cancer cells

Rab11-FIP2 can interact with MYO5B and plays an important role in regulating plasma membrane recycling. Our previous study has shown that MYO5B is epigenetically silenced and associated with c-Met signaling in human gastric cancer. However, little is known of the function of Rab11-FIP2 in gastric cancer. In this study, we investigated Rab11-FIP2 expression by immunohistochemistry in 86 patients with gastric cancer. We found that the expression level of Rab11-FIP2 was significantly increased in gastric cancer tissues and high expression of Rab11-FIP2 was closely correlated with nodal metastasis in gastric cancer patients. Rab11-FIP2 overexpression promoted epithelial-mesenchymal transition (EMT) in a manner associated with gastric cancer metastasis in vitro and in vivo. We also found that hypoxia could enhance the expression of Rab11-FIP2 through HIF-1α. Inactivation of Rab11-FIP2 dramatically decreased hypoxia-induced migration of gastric cancer cells. Suppression of the internalization of EGFR, at least in part, plays an important role in EMT induced by overexpression of Rab11-FIP2 in gastric cancer cells. Finally, we demonstrated that Rab11-FIP2 could regulate actin cytoskeleton dynamics. In conclusion, our findings reveal a novel mechanism underlying the role of Rab11-FIP2 in gastric cancer dissemination, suggesting that Rab11-FIP2 may be a promising candidate target for gastric cancer treatment.

Prognostic significance and frequency of EGFR expression and amplification in surgically resected advanced gastric cancer

OBJECTIVE

The aim of this study is to find the frequency and the role of epidermal growth factor receptor expression as a prognostic biomarker in gastric cancer.

METHODS

We evaluated the prognostic value and frequency of epidermal growth factor receptor expression and amplification using immunohistochemistry and silver in situ hybridization in a large cohort of curatively resected gastric cancer.

RESULTS

Of the total of 935 cases, 294 (31.4%), 101 (10.8%) and 36 (3.9%) patients showed epidermal growth factor receptor 1+, 2+ and 3+ expression on immunohistochemistry, respectively. Epidermal growth factor receptor-positive (2+/3+) patients more frequently had intestinal type than epidermal growth factor receptor-negative (0/1+) patients (82.5 vs. 44.1%, P < 0.001). After adjusting for sex, age, stage and adjuvant chemotherapy, epidermal growth factor receptor-positive patients had a favorable overall survival outcome compared with epidermal growth factor receptor-negative patients (hazard ratio, 0.734; 95% confidence interval, 0.541-0.997; P = 0.047), especially in Stage III disease (hazard ratio, 0.676; 95% confidence interval, 0.472-0.968; P = 0.033). Among the 393 cases available for  in situ hybridization, the correlation between immunohistochemistry and in situ hybridization was statistically significant (P = 0.001). Thirteen patients with gene amplification (3.3%) did not show different survival outcome with others (P = 0.359).

CONCLUSION

Epidermal growth factor receptor positivity was an independent favorable prognostic factor for gastric cancer, especially in Stage III disease.

Targeted therapies in gastric cancer treatment: where we are and where we are going

Gastric cancer (GC) is one of the most common malignancies and a major cause of cancer-related deaths worldwide. Its incidence has significantly declined over the last few decades, probably due to the identification of specific etiologic agents such as Helicobacter pylori and other dietary and environmental risk factors. Nevertheless, most of the cases are unfortunately diagnosed at an advanced stage justifying median overall survival rates frequently not exceeding one year. Palliative combination chemotherapy usually represented by a platinum-based doublet is the mainstay of treatment in the metastatic setting. Adding a third drug such as an anthracycline or a taxane has been shown to improve response rate and provide limited survival benefits in fit selected patients. Unlike other tumors, the introduction of molecularly targeted drugs in the medical armamentarium for GC is relatively recent with trastuzumab and ultimately ramucirumab constituting the only agents approved to date. Recent advances in the understanding of GC biology have led to the development of novel targeted therapies holding the promise to further improve treatment outcomes. The aim of this paper is to review the main available data coming from clinical trials of targeted drugs and to describe some of the most interesting molecules in clinical development in GC. These include drugs targeting EGFR, angiogenesis, c-MET, FGFR2, mTOR and immune checkpoints.

CD24 associates with EGFR and supports EGF/EGFR signaling via RhoA in gastric cancer cells

Background

CD24, a mucin-like membrane glycoprotein, plays a critical role in carcinogenesis, but its role in human gastric cancer and the underlying mechanism remains undefined.

Methods

The contents of CD24 and epidermal growth factor receptor (EGFR) in gastric cancer cells (SGC-7901 and BGC-823) and non-malignant gastric epithelial cells (GES-1) were evaluated by Western blotting assay. Cellular EGFR staining was examined by immunofluorescence assay. Cell migration rate was measured by wound healing assay. The effects of depletion/overexperssion of CD24 on EGFR expression and activation of EGF/EGFR singaling pathways were evaluated by immunofluorescence, qPCR, Western blotting and flow cytometry techniques. RhoA activity was assessed by pulldown assay. CD24 and EGFR expression patterns in human gastric tumor samples were also investigated by immunohistochemistry staining.

Results

CD24 was overexpressed in human gastric cancer cells. Ectopic expression of CD24 in gastric epithelial cells augmented the expression of EGFR, while knockdown of CD24 in gastric cancer cells decreased the level of EGFR and cell migration velocity. To further explore the mechanisms, we investigated the effect of CD24 expression on EGF/EGFR signaling. We noticed that this effect of CD24 on EGFR expression was dependent on promoting EGFR internalization and degradation. Lower ERK and Akt phosphorylations in response to EGF stimulation were observed in CD24-depleted cells. In addition, we noticed that the effect of CD24 on EGFR stability was mediated by RhoA activity in SGC-7901 gastric cancer cells. Analysis of gastric cancer specimens revealed a positive correlation between CD24 and EGFR levels and an association between CD24 expression and worse prognosis.

Conclusion

Thus, these findings suggest for the first time that CD24 regulates EGFR signaling by inhibiting EGFR internalization and degradation in a RhoA-dependent manner in gastric cancer cells.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-016-0787-y) contains supplementary material, which is available to authorized users.

Gene copy number gain of EGFR is a poor prognostic biomarker in gastric cancer: evaluation of 855 patients with bright-field dual in situ hybridization (DISH) method

BACKGROUND

EGFR overexpression is a prognostic biomarker and is expected to be a predictive biomarker for anti-EGFR therapies in gastric cancer. However, few studies have reported the clinical impact of EGFR gene copy number (GCN) and its correlation with EGFR overexpression.

METHODS

We used dual in situ hybridization (DISH) to detect EGFR GCN and chromosome 7 centromere (CEN7) in a set of tissue microarrays representing 855 patients with gastric cancer. These data were compared with those of immunohistochemical (IHC) analysis of EGFR expression to evaluate prognostic value.

RESULTS

EGFR GCN gain (≥ 2.5 EGFR signals per cell) was detected in 194 patients (22.7%) and indicated poor prognosis. Among 194 patients, EGFR amplification (EGFR/CEN7 ≥ 2.0) was observed in 29 patients (14.9%), which was almost identical to the IHC 3+ subgroup and worst prognostic subgroup. Patients with EGFR GCN gain but not amplification, including those exhibiting polysomy, also exhibited poorer prognosis than GCN non-gain patients and were distributed between IHC 0/1+ and 2+ subgroups. GCN gain was frequently observed in patients with more advanced disease, but served as an independent prognostic factor regardless of the pathological stage.

CONCLUSIONS

EGFR GCN gain is a more accurate prognostic biomarker than EGFR overexpression in patients with gastric cancer.

Nanobodies for targeted treatment of gastric cancer

With the development and application of monoclonal antibody-based targeted therapy drugs in recent years, some achievements have been made in the treatment of gastric cancer; however, because their preparation is relatively complex and expensive, their application is limited. Nanobodies have some advantages over conventional molecular targeted drugs, such as small molecular weight and unique structural features, and provide a new treatment strategy for targeted therapy of gastric cancer. In this paper, we review the nanobodies that have the potential for targeted treatment of gastric cancer.

The significance of NTR1 expression and its correlation with β-catenin and EGFR in gastric cancer

BACKGROUND

Several reports indicate the high-affinity receptor of NT (neurotensin), NTR1 (neurotensin receptor 1), in numerous detrimental functions linked to neoplastic progression of several cancer types. Recently, it has also been shown that NTR1 gene is a target of the Wnt/APC oncogenic pathways connected with the β-catenin/Tcf transcriptional complex and NT can stimulate cancer proliferation in an EGFR-dependent mechanism. In this study, we explored NTR1, β-catenin and EGFR expression in gastric cancer. The possible associations of NTR1 expression with clinicopathological factors, prognosis, β-catenin and EGFR were analyzed.

METHODS

NTR1, β-catenin and EGFR expression in gastric cancer tissues and the adjacent normal tissues of 210 cases was detected by Immunohistochemistry. The possible associations of NTR1 expression with clinicopathological data, prognosis, β-catenin and EGFR were analyzed.

RESULTS

1. NTR1 expression in tumor tissues was significantly higher than that in adjacent normal tissues (P <0 .01). 2. Its expression was positively correlated with pathological grade, T stage, N stage and TNM stage and was not correlated with sex, age, tumor size and Lauren's classification. 3. A co-expression of NTR1 and nuclear β-catenin was in 53 (25.2 %) of cases and NTR1 expression was positively correlated with β-catenin nuclear translocation. NTR1 expression was not correlated with EGFR expression, but at a critical value (P = 0.05). 4. By log-rank test, higher expression of NTR1, higher pathological grade, diffusion Lauren's classification and advanced TNM stage showed worse prognosis (P <0 .05). Age, sex, tumor size, β-catenin and EGFR had no prognostic significance. Multivariate Cox analysis showed that NTR1 expression and TNM clinical stage (P <0 .05) were the independent prognostic factors for patients with GC.

CONCLUSION

By immunohistochemistry, we found that a high expression of NTR1 in GC specimens, which showed a bad prognosis, besides, NTR1 expression was related to invasion and migration of GC. These findings provide new and important information on the progression of GC. This study indicated that NTR1 may play an important role in tumor progression of GC and have its potential to be a predictive biomarker or a therapeutic molecular target in GC. The interaction between NTR1 and β-catenin may participate in the development of GC. However, the relationship between NTR1 and EGFR needs to be further investigated.

Single nucleotide polymorphisms in AREG and EREG are prognostic biomarkers in locally advanced gastric cancer patients after surgery with curative intent

OBJECTIVE

Amphiregulin (AREG) and epiregulin (EREG) are important ligands to the epithelial growth factor receptor, which is involved in the regulation of progression and stemness in gastric cancer (GC). This study investigated whether frequent single nucleotide polymorphisms (SNPs) in genes of AREG and EREG are associated with recurrence-free survival and overall survival in patients with locally advanced GC.

METHODS

SNPs with a minor allele frequency of at least 10% were analyzed using direct DNA sequencing in two independent study populations.

RESULTS

The minor allele of AREG rs1615111 was associated with a significantly higher 3-year recurrence rate and lower 3-year survival rate [hazard ratio (HR)=2.21 and 2.35, respectively] compared with patients homozygous for the dominant allele G. The value for overall survival could be validated with a HR of 2.54 (P=0.018) in an independent cohort. Patients homozygous for the minor allele A of EREG rs12641042 had a significantly higher 3-year survival rate than patients with allele C (HR 0.48; P=0.034), but significance was lost in multivariable analysis (P=0.066). The value of rs12641042 could not be validated (P=0.98). Exploratory multivariable subgroup analysis showed the strongest prognostic value for rs1615111 in tumors with a diffuse histology (Pfor interaction=0.004).

CONCLUSION

AREG rs1615111, located in the AREG genomic region, can significantly define different prognostic cohorts in locally advanced GC. This value is most evident in GC patients with diffuse histology, which might be relevant as none of the trials testing epithelial growth factor receptor inhibitors has been enriched for diffuse histology or a molecularly defined population.

The prognostic impact of EGFR, ErbB2 and MET gene amplification in human gastric carcinomas as measured by quantitative Real-Time PCR

PURPOSE

Identification of critical genes which play pivotal roles in controlling tumor growth and survival will establish the basis for developing therapeutic targets. In this study, we focused on frequencies of EGFR, ErbB2 and MET gene amplification in gastric cancer patients to develop personalized medicine to improve the treatment.

METHOD

EGFR, ErbB2 and MET gene amplification, and mRNA expression were analyzed by the quantitative Real-Time PCR in paraffin-embedded samples from 115 patients with gastric cancer.

RESULTS

EGFR, ErbB2 and MET genes were amplified in 11.3 % (13/115), 6.1 % (7/115) and 19.1 % (22/115) of cancerous specimens, respectively. The correlation coefficient test clearly indicated that gene amplification in these three genes was positively correlated with mRNA transcription (EGFR: R = 0.631, p = 0.009; ErbB2: R = 0.652, p = 0.023; MET: R = 0.715, p < 0.001). EGFR and MET gene amplification was significantly associated with Ki-67 MI (p = 0.022 and p = 0.015). MET amplification was also significantly associated with age of ≥60 years (p = 0.021) and tumor size of ≥5 cm (p = 0.032). MET amplification, but not EGFR and ErbB2, was a significant prognostic factor in poor survival among patients with gastric cancer.

CONCLUSIONS

EGFR, ErbB2 and MET genes are frequently amplified in gastric carcinoma. EGFR, ErbB2 and MET gene amplification is positively correlated with mRNA transcription. MET gene amplification correlates with a poor prognosis and poor survival in gastric carcinomas.

Cell Free EGFR mRNA Expression and Implications for Survival and Metastasis in Non-Small Cell Lung Cancer Cases

BACKGROUND

NSCLC is a disease involving uncontrolled cell growth, which could result in metastases into nearby tissues beyond the lungs.

MATERIALS AND METHODS

The aim of the present study was to analyze the influence of epidermal growth factor receptor (EGFR) gene expression on metastasis and survival in NSCLC patients. The present case-control study included 100 cases of NSCLC patients and 100 age and sex matched controls. EGFR gene expression was analyzed by quantitative real time PCR using serum RNA. Association with NSCLC patient survival was analyzed by the Kaplan-Meier method.

RESULTS

We analyzed EGFR gene expression and observed mean increased gene expression of 13.5 fold in NSCLC patients. Values reflected overall survival of patients with a median of 15.8 months in the cases of <13 fold increased gene expression vs 6.7 months with >13 fold increased EGFR gene expression (p=0.005). Distant metastatic patients with <13 fold increased EGFR gene expression had 7.9 months of median survival time while>13 fold increased EGFR gene expression had only 5 months of median survival time (p=0.03). Non metastatic patients with <13 fold increased EGFR gene expression had 18 months of median survival time as compared to only 7.1 months with >13 fold increased expression.

CONCLUSIONS

Higher cell free EGFR mRNA expression may play an important role in causing distant metastases and reducing overall survival of NSCLC patients in the Indian population.

Causes and consequences of microsatellite instability in gastric carcinogenesis

Loss of DNA mismatch repair (MMR) function, due to somatic or germline epi/genetic alterations of MMR genes leads to the accumulation of numerous mutations across the genome, creating a molecular phenotype known as microsatellite instability (MSI). In gastric cancer (GC), MSI occurs in about 15% to 30% of the cases. This review summarizes the current knowledge on the molecular mechanisms underlying the acquisition of MSI in GC as well as on the clinic, pathologic and molecular consequences of the MSI phenotype. Additionally, current therapeutic strategies for GC and their applicability in the MSI subset are also discussed.

Prognostic impact of major receptor tyrosine kinase expression in gastric cancer

BACKGROUND

Various kinds of molecular targeted drugs to inhibit receptor tyrosine kinases (RTKs) have been recently developed. The relationship between the expression status of major RTKs and prognosis in gastric cancer remains unclear. We conducted a multicenter study to evaluate the prognostic impact of the expression of epidermal growth factor receptor (EGFR), c-Met, platelet-derived growth factor receptor (PDGFR), and c-Kit in gastric cancer.

METHODS

This study included 153 gastric cancer patients who underwent gastrectomy at 9 institutions between 2000 and 2006. Expression status of EGFR, c-Met, PDGFR, and c-Kit were evaluated with immunohistochemistry (IHC) centrally. Overall survival based on RTK expression status was statistically compared. Cox multivariate analysis was conducted to adjust for potentially confounding factors.

RESULTS

The positive rates for EGFR, c-Met, PDGFR, and c-Kit were 14.4, 24.8, 41.2, and 11.1 %, respectively. Significant interactions with expression status were observed for pathological N stage with EGFR; HER2-status with c-Met; tumor location, histology, and pathological N stage with PDGFR; and no examined variables with c-Kit. Concomitant HER2 positivity was observed for 0.7 % of tumors positive for EGFR, 3.9 % for c-Met, 4.6 % for PDGFR, and 1.3 % for c-Kit. There were some differences in overall survival between patients with or without RTK expression, but only c-Kit expression showed a significant survival difference in Cox multivariate analysis (P = 0.046).

CONCLUSIONS

Our multicenter study indicated that IHC expression of 4 RTKs had some prognostic impact and that c-Kit-positive status may be a significant indicator of good prognosis in gastric cancer patients.

EGFR protein expression and gene amplification in squamous intraepithelial lesions and squamous cell carcinomas of the cervix

The purpose of this study was to evaluate the protein expression and gene amplification of epithelial growth factor receptor (EGFR) in intraepithelial neoplasias and squamous cell carcinoma of the cervix and to determine the value of EGFR in carcinogenesis, progression, and prognosis of cervical cancer. EGFR protein expression and gene amplification involved gene copy number in 75 cases of cervical various lesions were evaluated using immunohistochemistry and by fluorescence in situ hybridization (FISH) techniques. Expression of EGFR was observed in 76.00% of the high-grade CIN and 79.17% of the invasive carcinomas. In contrast, there were low levels of EGFR expression in chronic cervicitis (1/10) and low-grade CIN (7/16). There were statistically significant differences among them (P<0.05). Gene amplification was detected in 20.51% high-grade CIN and invasive carcinoma, but there only 4.35% EGFR gene amplification was observed in chronic cervicitis and low grade CIN. Among the 42 patients with negative or low levels of EGFR expression, 26 patients (61.90%) were found to have diploidy and 11 patients (26.20%) to have balanced triploidy. However, among the 20 patients with an intermediate and high levels of EGFR protein expression, 13 (65.00%) were found to have balanced polyploidy or gene amplification. All cases of EGFR gene amplification involved intermediate and high levels of protein expression. EGFR may be involved in the carcinogenesis of the cervix and may be an early event during the carcinogenesis. Overexpression of EGFR protein may result from gene amplification and increases in gene copy number.

The role of epidermal growth factor receptor in prognosis and treatment of gastric cancer

Despite tremendous efforts to reduce deaths due to gastric cancer, it represents the second leading cause of cancer-related deaths worldwide. EGF receptor (EGFR) plays important roles in gastric carcinogenesis by regulation of cell cycle, angiogenesis and apoptosis. This review evaluates the functions, mechanisms and clinical uses of EGFR in gastric cancer. Although EGFR targeted single therapy shows limited effect, the combination of EGFR targeted agents with traditional chemotherapy regimens may bring about important progress in cancer therapy. More clinical trials should be performed to clarify both the prognostic and therapeutic value of EGFR in gastric cancer.

Effect of epidermal growth factor receptor status on the outcomes of patients with metastatic gastric cancer: A pilot study

The expression of epidermal growth factor receptor (EGFR) has been linked to clinical outcome in several solid tumors. However, the clinical significance of EGFR (c-erbB1) in gastric cancer remains unclear. The present study was designed to detect the clinical implications of EGFR in the Turkish population. Paraffin-embedded tissue microarrays containing gastric cancer tissue were obtained from 30 patients. EGFR expression was detected using immunohistochemistry. The correlation of this biomarker to the clinicopathological features and survival of patients with gastric cancer was studied. The overall positivity rate of EGFR was 63.3%. EGFR expression was significantly correlated with an improved progression-free survival (PFS) and overall survival (OS) rate (P=0.039 and 0.01, respectively). EGFR expression is a good prognostic marker for patients with gastric cancer.

Relationship between expression of EGFR in gastric cancer tissue and clinicopathological features

OBJECTIVE

To investigate the relationship between the expression of epidermal growth factor receptor (EGFR) in gastric cancer and the clinicopathological features and prognosis.

METHODS

A total of 78 paraffin specimens of gastric cancer operation were collected. The immunohistochemical method was used to detect the expression of EGFR in 78 cases of gastric cancer and 20 cases of adjacent normal tissue. The relationship between the high expression of EGFR and clinicopathological features was analyzed.

RESULTS

EGFR positive expression rate in the 78 cases of gastric cancer tissue was 57.7 % (45/78), while EGFR was not expressed in 20 cases of adjacent normal tissue. The high EGFR expression was positively correlated with the position of gastric cancer, tumor size, cell differentiation, invasive depth, lymph node metastasis and TNM staging, yet having no obvious relation with gender or age.

CONCLUSIONS

EGFR expression level in gastric cancer is closely related to the incidence and development of gastric cancer, which can provide a theoretical basis for the targeted therapy for gastric cancer with EGFR as the target.

Therapeutic targets associated to E-cadherin dysfunction in gastric cancer

INTRODUCTION

Epithelial cadherin (E-cadherin) plays a key role in epithelial cell-cell adhesion, contributing to tissue differentiation and homeostasis. Throughout the past decades, research has shed light on the molecular mechanisms underlying E-cadherin's role in tumor progression, namely in invasion and metastization. Emerging evidence established E-cadherin as a tumor suppressor and suggests that targeting E-cadherin or downstream signaling molecules may constitute effective cancer therapeutics.

AREAS COVERED

This review aims to cover E-cadherin-mediated signaling during cancer development and progression and highlight putative therapeutic targets.

EXPERT OPINION

Reconstitution of E-cadherin expression or targeting of E-cadherin downstream molecules holds promise in cancer therapies. Considering the high frequency of CDH1 promoter hypermethylation as a second hit in malignant lesions from hereditary diffuse gastric cancer patients, histone deacetylase inhibitors are potential therapeutic agents in combination with conventional chemotherapy, specifically in initial tumor stages. Concerning E-cadherin-mediated signaling, we propose that HER receptors (as epidermal growth factor receptor) and Notch downstream targets are clinically relevant and should be considered in gastric cancer therapeutics and control.

Prognostic value of epidermal growth factor receptor in patients with gastric cancer: a meta-analysis

BACKGROUND

The epidermal growth factor receptor (EGFR) plays important roles in the development of gastric cancer. This study aims to analyze the prognostic value of EGFR in patients with gastric cancer.

METHODS

A meta-analysis is performed by searching Cochrane Library, PubMed, EMBASE and Science Direct databases from Jan 1970 to May 2013. Data are extracted from studies evaluating the survival of gastric cancer patients with either positive or negative EGFR expression. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) are calculated.

RESULTS

Totally 1600 cases of gastric cancer patients from five studies are subjected to final analysis. The HR of post-operational survival of patients with positive EGFR expression is 1.16 (95% CI: 0.94-1.43) as compared with those with negative expression, indicating that positive EGFR expression does not significantly predict the poor survival of gastric cancer.

CONCLUSIONS

EGFR expression is not an independent predictor for the survival of gastric cancer patients.