Gastric cancer: a primer on the epidemiology and biology of the disease and an overview of the medical management of advanced disease

Targeted Therapies for Advanced Oesophagogastric Cancer: Recent Progress and Future Directions

The genomic landscape of oesophagogastric (OG) cancer is highly complex. The recent elucidation of some of the pathways involved has suggested a number of novel targets for therapy. This therapy is urgently required as with conventional chemotherapy regimens patients with advanced OG cancer still have a median overall survival of under a year. This review outlines the rationale for the current treatment of OG cancer with chemotherapy and describes both previously conducted and ongoing clinical trials of novel agents in this area. The targets and associated treatments discussed include HER-2, EGFR, VEGF, c-Met, FGFR-2, PI3K, mTOR andIGF-1. To date only two targeted treatments, trastuzumab and ramucirumab, have become part of the treatment paradigm for OG cancer, partly due to difficulties in defining predictive biomarkers in this disease. However, there are a number of promising drugs in the pipeline and this article seeks to describe these and other potential novel approaches including targeting DNA repair deficiencies and the immune system.

The safety and efficacy of ramucirumab in combination with paclitaxel for the treatment of advanced gastric or gastro-esophageal junction adenocarcinoma

INTRODUCTION

Gastric cancer (GC) is a health problem. Platinum and fluoropyrimidine-based combinations have been established as first-line drugs used worldwide. However, there are no other options for treatment if first-line therapy fails. Therefore, second-line treatment options are needed. Targeted therapies have optimized the results of chemotherapy, specifically trastuzumab as a first-line and ramucirumab in second-line.

AREAS COVERED

Vascular endothelial growth factor (VEGF) and VEGF receptor-2 (VEGFR-2) are involved in the pathogenesis of GC. Clinical studies have evaluated VEGFR-2 blocked in second line. Two phase III trials using ramucirumab alone or associated to paclitaxel have demonstrated that second-line therapy could improve the survival of patients with GC. Expert commentary: VEGF-2 receptor blockade is effective at treating GC. The combination of paclitaxel with ramucirumab can be used to establish an angiogenic blockade in second-line therapy. The magnitude of the treatment effect suggests that this combination should be used as the current standard.

Improved survival in resected oesophageal and gastric adenocarcinomas over a decade: the Royal Marsden experience 2001-2010

BACKGROUND

Oesophageal and gastric adenocarcinoma (OGA) treatment remains challenging. Improvements in early diagnosis, staging and management might have contributed to survival prolongation. To examine this hypothesis, we assessed outcomes of resected OGA patients in our institution over 10 years, comparing two time periods, 2001-2005 and 2006-2010.

METHODS

Records from patients who had undergone surgery with radical intent and follow-up for OGA were retrospectively reviewed. Patients followed up at hospitals other than the Royal Marsden Hospital were excluded. Two different cohorts were identified: patients with oesophageal and type I or type II oesophagogastric junction (OGJ) tumours, and patients with gastric and type III OGJ tumours.

RESULTS

We identified 360 patients: 147 from 2001-2005 and 213 from 2006-2010. The characteristics were comparable across the two time periods. Between 2001-2005 and 2006-2010, the percentage of R0 resections increased (from 67.1 to 81.1 % for proximal tumours and from 76.3 to 95.9 % for gastric and type III OGJ tumours). The mean number of lymph nodes retrieved increased over time. The 5-year overall survival rate increased significantly from 42.3 to 56.6 % for proximal tumours and from 38.8 to 55.3 % for gastric and type III OGJ tumours. Similarly, the disease-free survival rate significantly increased from 34.6 to 53.5 % for proximal tumours and from 35.9 to 51.1 % for gastric and type III OGJ tumours.

CONCLUSION

This study comprehensively describes the improvement in survival outcomes in a major UK referral centre over a 10-year period, identifying potentially relevant factors such as increased number of R0 resections and higher lymph node yield.

Immunotherapy for Gastroesophageal Cancer

Survival for patients with advanced oesophageal and stomach cancer is poor; together these cancers are responsible for more than a million deaths per year globally. As chemotherapy and targeted therapies such as trastuzumab and ramucirumab result in modest improvements in survival but not long-term cure for such patients, development of alternative treatment approaches is warranted. Novel immunotherapy drugs such as checkpoint inhibitors have been paradigm changing in melanoma, non-small cell lung cancer and urothelial cancers. In this review, we assess the early evidence for efficacy of immunotherapy in patients with gastroesophageal cancer in addition to considering biomarkers associated with response to these treatments. Early results of Anti- Programmed Cell Death Protein-1 (anti-PD-1), anti-PD-L1 and anti-Cytotoxic T-lymphocyte assosciated protein-4 (anti-CTLA4) trials are examined, and we conclude with a discussion on the future direction for immunotherapy for gastroesophageal cancer patients.

Novel long non-coding RNA GACAT3 promotes gastric cancer cell proliferation through the IL-6/STAT3 signaling pathway

Long non-coding RNAs (lncRNAs) play an important role in cancer occurrence and development. We previously demonstrated that lncRNA gastric cancer-associated transcript 3 (GACAT3) was positively correlated with TNM stages, tumor size, and distant metastasis of patients with gastric cancer. However, the role of GACAT3 in gastric cancer remains unclear. In this study, to investigate its function, we synthesized small interference RNAs (siRNAs) against GACTA3 and developed a GACAT3 overexpression vector (pcDNA3-GACAT3), respectively. The siRNA-mediated knockdown of GACAT3 significantly decreased cell proliferation of the gastric cancer HGC-27 cells, in which GACAT3 is overexpressed. Furthermore, GACAT3 overexpression in gastric cancer SGC-7901 cells promoted cell growth. Moreover, GACAT3 expression in HGC-27 cells was greatly upregulated by IL-6 treatment in a concentration-dependent manner. In contrast, siRNA-mediated knockdown of STAT3 decreased GACAT3 expression even in the presence of IL-6. These results demonstrated that as a downstream target of the IL6/STAT3 signaling, lncRNA GACAT3 promotes gastric cancer cell growth suggesting that GACAT3 is an inflammatory response gene and may be served as a valuable potential target for the treatment of gastric cancer.

Histologic types of gastric cancer among migrants from the former Soviet Union and the general population in Germany: what kind of prevention do we need?

OBJECTIVE

The incidence of gastric cancer (GC) is high among migrants from Eastern Europe and Asia, but a detailed picture of disease characteristics is missing. Our study examined the incidence of histologic types among resettlers from the former Soviet Union and the general population in Germany to draw conclusions on risk factors and possible prevention strategies.

METHODS

Between 1990 and 2009, all GC diagnoses among a cohort of 18 619 resettlers residing in the Saarland were identified in the Saarland Cancer Registry database. Age-standardized incidence rates (ASRs) of the entire Saarland population and standardized incidence ratios (SIRs) of resettlers compared with the Saarland population were calculated for types according to Laurén. In addition, ASRs and SIRs were modeled using Poisson's regression to investigate time trends.

RESULTS

The ASR of intestinal GC in the Saarland population decreased over time, whereas the ASR of diffuse GC remained unchanged. Resettlers' incidence of intestinal GC was elevated among men [SIR: 3.04, 95% confidence interval (CI): 2.05-4.50] and women (SIR: 2.78, 95% CI: 1.61-4.79), whereas diffuse GC was elevated only among women (SIR: 1.98, 95% CI: 1.07-3.69). No time trends for SIRs could be observed in regression analysis.

CONCLUSION

Different trends of diffuse GC incidence in Germany and the USA underline the importance of environmental risk factors. The continuously elevated risk of GC among male resettlers is probably associated with risk factors affecting exclusively the intestinal type such as a low intake of fruit and vegetables and heavy alcohol consumption. Future prevention programs for resettlers should include dietary measures.

Clinical role of ramucirumab alone or in combination with paclitaxel for gastric and gastro-esophageal junction adenocarcinoma

Cancers of the stomach and gastro-esophageal junction represent a significant challenge in oncology. Despite some recent advances in genetic categorization and the development of novel agents, outcomes remain poor. The vascular endothelial growth factor receptor 2 monoclonal antibody ramucirumab is the first targeted therapy to improve survival in a molecularly unselected population, and represents a valuable new treatment option. This review describes the current treatment landscape for advanced disease, evaluates existing and ongoing research into ramucirumab, and discusses its current and potential future therapeutic role.

Immunotherapy for oesophagogastric cancer

INTRODUCTION

Gastric and oesophageal cancers are a pressing global health problem with high mortality rates and poor outcomes for advanced disease. The mainstay of treatment in the palliative setting has traditionally been chemotherapy, which accrues only modest survival benefits. As with other cancer types, there is increasing interest in the use of immunotherapy approaches to improve outcomes.

AREAS COVERED

This paper reviews the aetiological and genetic characteristics of oesophagogastric (OG) cancers relevant to the application of immunotherapy and outlines the historical, present-day and potential future applications of immunotherapy in their management.

EXPERT OPINION

The use of agents targeting the PD1 pathway have led to impressive and durable responses in a minority of OG cancer patients and it would be expected that combinatorial approaches with chemotherapy, radiotherapy and other biological agents will improve responses further. Identification of clinically robust biomarkers is crucial in refining such approaches moving forwards. The application of modern sequencing technology to the development of personalized neoantigen-based vaccines represents an exciting amalgamation of genomics and immunotherapy, with potentially important clinical implications in OG cancer.

Decreased expression of Calpain-9 predicts unfavorable prognosis in patients with gastric cancer

Calpain-8 and calpain-9 belong to the family of calcium-dependent cysteine proteases, which are highly expressed in the stomach. However, the roles of calpain-8 and calpain-9 in gastric tumorigenesis remain little understood. Herein, we demonstrated that calpain-9 was generally decreased in gastric cancer cell lines and primary tumor tissues, while calpain-8 expression was not significantly altered. Calpain-9, but not calpain-8, induced cell cycle arrest in the G1 phase and cellular apoptosis in vitro, and it attenuated the growth of subcutaneous tumor xenografts in vivo. Low expression of calpain-9 was positively associated with male sex, late T stage, lymph node metastasis, and advanced TNM stage. Further analysis identified calpain-9 as an independent prognostic factor for poor prognosis, and combining calpain-9 with TNM stage generated a better predictive model for patient outcomes. In conclusion, calpain-9 is a tumor suppressor that can be regarded as a potential prognosis indicator for clinical outcomes in gastric cancer.

Rho GTPase RhoJ is Associated with Gastric Cancer Progression and Metastasis

Rho GTPases play a pivotal role in tumor progression by regulating tumor cell migration and invasion. However, the role of Rho GTPases in gastric cancer (GC) remains unexplored. This study aimed to investigate the clinical implications of RhoJ, which is an uncharted member of Rho family. RhoJ expression in human GC cell lines and surgical specimens from GC patients were analyzed. Moreover, in vitro gain-of-function analysis was performed to evaluate the malignant phenotypes of RhoJ-overexpressing GC cells. The extent of RhoJ expression varied among GC cell lines and GC patients. YCC-9 cell line displayed the strongest expression, while YCC-10, -11, and -16 showed scant expressions. Of the 70 GC patients, 34 (48.6%) had RhoJ expression in their GC tissue, and patients with high RhoJ expression had more diffuse type GC (73.5% vs. 41.7%), were at more advanced stages (stage III, IV: 85.3% vs. 58.4%), and had more frequent metastasis (47.1% vs. 11.1%), denoting that RhoJ has a potential role in GC progression and metastasis. High RhoJ expression significantly correlated with poor overall survival and recurrence-free survival after surgical resection of gastric cancer. Finally, In vitro gain-of-function experiments showed 41.3% enhanced motility and 60.4% enhanced invasiveness in RhoJ-overexpressing GC cells compared to control, with negligible difference in cell proliferation. Collectively, high RhoJ expression is an independent negative prognostic factor for the survival outcome of GC and correlated with the increased cell motility and invasiveness.

Primary Tumor Resection and Survival in Patients with Stage IV Gastric Cancer

Purpose

The aim of this study was to determine whether surgical resection of the primary tumor contributes to survival in patients with metastatic gastric cancer.

Materials and Methods

A total of 288 patients with metastatic gastric cancer from the Akdeniz University, Antalya Training and Research Hospital, and the Meram University of Konya database were retrospectively analyzed. The effect of primary tumor resection on survival of patients with metastatic gastric cancer was investigated using the log-rank test. Kaplan-Meier survival estimates were calculated. Multivariate analysis was performed using Cox proportional hazards regression modeling.

Results

The median overall survival was 12.0 months (95% confidence intewrval [CI], 10.4~13.6 months) and 7.8 months (95% CI, 5.5~10.0 months) for patients with and without primary tumor resection, respectively (P<0.001). The median progression-free survival was 8.3 months (95% CI, 7.1~9.5 months) and 6.2 months (95% CI, 5.8~6.7 months) for patients with and without primary tumor resection, respectively (P=0.002).

Conclusions

Non-curative gastrectomy in patients with metastatic gastric cancer might increase their survival rate regardless of the occurrence of life-threatening tumor-related complications.

Efficacy and toxicity of salvage weekly paclitaxel chemotherapy in non-Asian patients with advanced oesophagogastric adenocarcinoma

OBJECTIVES

Survival for oesophagogastric adenocarcinoma (OGA) patients varies globally and clinical trial results are seldom replicated in clinical practice. We sought to examine the efficacy and toxicity of salvage paclitaxel chemotherapy for patients with advanced OGA at our institution.

METHODS

Advanced OGA patients treated with paclitaxel between June 2011 and February 2014 were identified from the electronic record at the Royal Marsden Hospital (RMH), London. Chart review was performed to obtain demographics, performance status (PS), laboratory parameters, radiological response and dates of progression, death and last follow up. Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan-Meier method. Multivariate Cox regression analysis examined the interaction between clinical and laboratory parameters and survival.

RESULTS

Fifty-seven patients were identified; OS and PFS were 5.8 and 2.6 months respectively. From first-line chemotherapy, median OS was 14.3 months. Two-year and three-year survival rates from diagnosis were 26% and 13%. More than or equivalent to Grade 3 neutropenia occurred in 13% of patients. In multivariate analysis, PS more than or equal to 2, alkaline phosphatase (ALP) more than or equal to100 U/L, and previous rechallenge with platinum were independent prognostic factors for OS.

CONCLUSIONS

OGA cancer patients treated at RMH with salvage paclitaxel had an OS equivalent to patients in clinical trials with more (33%) PS = 2 patients treated and less haematological toxicity than Asian patients. Eastern Cooperative Oncology Group (ECOG) PS more than or equal to 2, ALP more than or equal to 100 U/L, and prior platinum rechallenge were associated with poor survival. However, the proportion of patients surviving more than or equal to two years from diagnosis demonstrates a clinically relevant improvement from historical controls.

Subgroup analysis of East Asians in RAINBOW: A phase 3 trial of ramucirumab plus paclitaxel for advanced gastric cancer

BACKGROUND AND AIM

East Asia has higher gastric cancer incidence and mortality rates than other regions. We present a subgroup analysis of East Asians in the positive study RAINBOW.

METHODS

Patients with advanced gastric or gastroesophageal junction adenocarcinoma previously treated with platinum and fluoropyrimidine received ramucirumab 8 mg/kg or placebo on days 1 and 15 plus paclitaxel 80 mg/m(2) on days 1, 8, and 15 of a 28-day cycle.

RESULTS

Of 665 intention-to-treat patients, 223 were East Asian. Median overall survival was 12.1 months for ramucirumab plus paclitaxel and 10.5 months for placebo plus paclitaxel (hazard ratio: 0.986, 95% confidence interval: 0.727-1.337, P = 0.929). Median progression-free survival was 5.5 months for ramucirumab plus paclitaxel and 2.8 months for placebo plus paclitaxel (hazard ratio: 0.628, 95% confidence interval: 0.473-0.834, P = 0.001). Objective response rates were 34% for ramucirumab plus paclitaxel and 20% for placebo plus paclitaxel. Grade ≥ 3 neutropenia (60% vs 28%) and leukopenia (34% vs 13%) were higher for ramucirumab plus paclitaxel. The rate of febrile neutropenia was low (4% vs 4%). Special interest adverse events included any grade bleeding/hemorrhage (55% vs 25%), proteinuria (27% vs 7%), and hypertension (22% vs 2%).

CONCLUSIONS

Ramucirumab plus paclitaxel significantly improves progression-free survival and response rate, with prolonged median overall survival and an acceptable safety profile in East Asians with advanced gastric cancer.

Evaluation of HER2 by automated FISH and IHC in gastric carcinoma biopsies

PURPOSE

The use of trastuzumab (Herceptin) to target HER2 has been applied in breast carcinoma and gastric carcinoma (GC). Previous studies have tested trastuzumab's effectiveness by assessing HER2 expression or HER2 amplification by means of immunohistochemistry (IHC) or fluorescence in situ hybridization (FISH). In this work we aimed to evaluate automated FISH and IHC technologies for HER2 detection in GC biopsies to be used in routine pathology practice.

METHODS

The study used an Oracle HER2 IHC System and an LSI HER2/CEP17 Dual Probe on an automated Bond system (Leica Microsystems). One hundred GC biopsies were evaluated including 44 intestinal type, 38 diffuse type and 18 indeterminate type according to Lauren's classification.

RESULTS

The overall concordance rate between the automated FISH and IHC methods was 94% (κ = 0.87), as 6 samples were scored as equivocal (4 in IHC and 2 in FISH). Moreover, HER2 positivity was significantly different between the 3 types of GC (p<0.05), being more frequent in intestinal-type GC (23%) than in the other 2 histological types (5% and 0%). Finally, the HER2/CEP17 FISH ratio was significantly different (p<0.01) between disomic and polysomic samples, being higher in polysomic samples (mean 1.633 ± 0.509) than in disomic samples (mean 1.231 ± 0.675).

CONCLUSIONS

Automated HER2 testing of GC biopsies using the Leica Bond system was useful and efficient. This method allowed us to improve normal routine procedures, minimizing time and costs as well as handling and observation errors.

Repertaxin, an inhibitor of the chemokine receptors CXCR1 and CXCR2, inhibits malignant behavior of human gastric cancer MKN45 cells in vitro and in vivo and enhances efficacy of 5-fluorouracil

Chemokine-mediated activation of G protein-coupled receptors CXCR1/2 promotes tumor growth, invasion, inflammation and metastasis. Repertaxin, a CXCR1/2 small-molecule inhibitor, has been shown to attenuate many of these tumor-associated processes. The present study aimed to investigate the effects of repertaxin alone and in combination with 5-fluorouracil (5-FU) on the malignant behavior of gastric cancer and the potential mechanisms. Gastric cancer MKN45 cells were treated in vitro with repertaxin and 5-FU, either alone or in combination. MTT and colony formation assay were performed to assess proliferation. Cell cycle progression and apoptosis was completed by flow cytometry. Migration and invasion were also assessed by Transwell and wound-healing assay. Western blot analysis and quantitative RT-PCR were performed to determine expression of signaling molecules. MKN45 cells were also grown as xenografts in nude mice. Mice were treated with repertaxin and 5-FU, and tumor volume and weight, angiogenesis, proliferation and apoptosis were monitored. Combination of repertaxin and 5-FU inhibited MKN45 cell proliferation and increased apoptosis better than either agent alone. Similarly, enhanced effect of the combination was also observed in migration and invasion assays. The improved effect of repertaxin and 5-FU was also observed in vivo, as xenograft models treated with both compounds exhibited significantly decreased tumor volume and increased apoptosis. In conclusion, repertaxin inhibited malignant behavior of human gastric cancer MKN45 cells in vitro and in vivo and enhances efficacy of 5-fluorouracil. These data provide rationale that targeting CXCR1/2 with small molecule inhibitors may enhance chemotherapeutic efficacy for the treatment of gastric cancer.

MEF2D/Wnt/β-catenin pathway regulates the proliferation of gastric cancer cells and is regulated by microRNA-19

The underlying molecular pathogenesis in gastric cancer remains poorly unknown. The transcription factor myocyte enhancer factor 2D (MEF2D) participates in the initiation and development of many human cancers. However, its potential roles in gastric cancer have surprisingly not been studied. In present study, we first explored MEF2's expression in gastric cancer, finding that only MEF2D rather than MEF2A, 2B, or 2C was elevated in gastric cancer clinical specimens. Furthermore, immunohistochemical analysis on the tissue samples obtained from 260 patients with gastric cancer revealed that MEF2D expression was significantly associated with the clinical stage, vascular invasion, metastasis, and tumor size. Gastric cancer patients with MEF2D expression showed a significantly shorter overall survival time compared with that of patients lacking of MEF2D. Multivariate analysis revealed that MEF2D expression was an independent prognostic factor for overall survival. These results indicated that MEF2D was a prognostic marker for gastric cancer. Notably, MEF2D silencing was able to reduce the proliferation and survival of gastric cancer cells. Further study revealed that MEF2D suppression significantly inactivated the oncogenic Wnt/β-catenin pathway. Downregulation of MEF2D inhibited the tumorigenesis of gastric cancer cells in nude mice. Finally, MEF2D is a direct target of miR-19, which was found to be decreased in gastric cancer clinical specimens. Collectively, we found that miR-19/MEF2D/Wnt/β-catenin regulatory network contributes to the growth of gastric cancer, hinting a new promising target for gastric cancer treatment.

The descriptive epidemiology of gastric cancer in Central America and comparison with United States Hispanic populations

PURPOSE

The aims of this study were to delineate the epidemiology of gastric adenocarcinoma in Central America and contrast it with Hispanic-Latino populations in the USA.

METHODS

Published literature and Central America Ministry of Health databases were used as primary data sources, including national, population-based, and hospital-based registries. US data was obtained from the National Cancer Institute (NCI)-Epidemiology End Results Program (SEER) registry. Incident gastric adenocarcinoma cases were analyzed for available data between 1985 and 2011, including demographic variables and pathology information.

RESULTS

In Central America, 19,741 incident gastric adenocarcinomas were identified. Two thirds of the cases were male, 20.5 % were under age 55, and 58.5 %were from rural areas. In the SEER database (n = 7871), 57.8 % were male and 28.9 % were under age 55. Among the US Hispanics born in Central America with gastric cancer (n = 1210), 50.3 % of cases were male and 38.1 % were under age 55. Non-cardia gastric cancer was more common in Central America (83.3 %), among US Hispanics (80.2 %), and Hispanics born in Central America (86.3 %). Cancers of the antrum were more common in Central America (73.6 %), whereas cancers of the corpus were slightly more common among US Hispanics (54.0 %). Adenocarcinoma of the diffuse subtype was relatively common, both in Central America (35.7 %) and US Hispanics (69.5 %), although Lauren classification was reported in only 50 % of cases.

CONCLUSIONS

A significant burden of gastric adenocarcinoma is observed in Central America based upon limited available data. Differences are noted between Central America and US Hispanics. Strengthening population-based registries is needed for improved cancer control in Central America, which may have implications for the growing US Hispanic population.

Identification of low abundance microbiome in clinical samples using whole genome sequencing

Identifying the microbiome composition from primary tissues directly affords an opportunity to study the causative relationships between the host microbiome and disease. However, this is challenging due the low abundance of microbial DNA relative to the host. We present a systematic evaluation of microbiome profiling directly from endoscopic biopsies by whole genome sequencing. We compared our methods with other approaches on datasets with previously identified microbial composition. We applied this approach to identify the microbiome from 27 stomach biopsies, and validated the presence of Helicobacter pylori by quantitative PCR. Finally, we profiled the microbial composition in The Cancer Genome Atlas gastric adenocarcinoma cohort.

Endoscopic ultrasonography for staging depth of invasion in early gastric cancer: A meta-analysis

BACKGROUND AND AIM

Endoscopic ultrasonography (EUS) is a widely used imaging modality for detecting the depth of early gastric cancer (EGC) invasion. However, the studies pertaining to EUS for staging early gastric cancer have reported widely varied sensitivities and specificities. This study was conducted to estimate the overall diagnostic accuracy of EUS for staging the depth in EGCs.

METHODS

The literatures were identified by searching in PubMed, Embase, and Web of Knowledge databases. Two reviewers independently extracted the information from the literatures for constructing 2 × 2 table. A random-effect model or a fixed-effect model was used to estimate the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio. A summary receiver operating characteristic curve also was constructed. Meta-regression and subgroup analysis were used to explore the sources of heterogeneity.

RESULTS

The pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of EUS for M staging were 76% (95% confidence interval [CI], 74-78%), 72% (95% CI, 69-75%), 3.67 (95% CI, 2.48-5.44), and 0.31 (95% CI, 0.24-0.40), respectively. For SM staging, these results were 62% (95% CI, 59-66%), 78% (95% CI, 76-80%), 2.99 (95% CI, 2.26-3.96), and 0.43 (95% CI, 0.32-0.57), respectively. For M/SM1 staging, they were 90% (95% CI, 88-92%), 67% (95% CI, 61-72%), 3.14 (95% CI, 2.08-4.73), and 0.12 (95% CI, 0.07-0.22), respectively. The area under the curve for mucosal, submucosal, and mucosal/minimal submucosal invasion staging were 0.85, 0.82, and 0.81, respectively.

CONCLUSIONS

Endoscopic ultrasonography only has a relatively low accuracy for staging the depth of invasion in EGCs. Accordingly, EUS may be not indispensable in the staging of EGCs.

Ramucirumab for advanced gastric cancer or gastro-oesophageal junction adenocarcinoma

Ramucirumab, a fully humanized monoclonal antibody directed against vascular endothelial growth factor receptor 2, is the first targeted agent to have demonstrated an improvement in survival, as a single agent or in combination, in a molecularly unselected population in gastro-oesophageal cancer. Now that second-line treatment is routinely considered for patients with advanced gastro-oesophageal cancer, ramucirumab, with its favourable toxicity profile compared with cytotoxic treatment, provides a valuable additional treatment option.

Clinical Relevance of the Tumor Location-Modified Lauren Classification System of Gastric Cancer

Purpose

The Lauren classification system is a very commonly used pathological classification system of gastric adenocarcinoma. A recent study proposed that the Lauren classification should be modified to include the anatomical location of the tumor. The resulting three types were found to differ significantly in terms of genomic expression profiles. This retrospective cohort study aimed to evaluate the clinical significance of the modified Lauren classification (MLC).

Materials and Methods

A total of 677 consecutive patients who underwent curative gastrectomy from January 2005 to December 2007 for histologically confirmed gastric cancer were included. The patients were divided according to the MLC into proximal non-diffuse (PND), diffuse (D), and distal non-diffuse (DND) type. The groups were compared in terms of clinical features and overall survival. Multivariate analysis served to assess the association between MLC and prognosis.

Results

Of the 677 patients, 48, 358, and 271 had PND, D, and DND, respectively. Their 5-year overall survival rates were 77.1%, 77.7%, and 90.4%. Compared to D and PND, DND was associated with significantly better overall survival (both P<0.01). Multivariate analysis showed that age, differentiation, lympho-vascular invasion, T and N stage, but not MLC, were independent prognostic factors for overall survival. Multivariate analysis of early gastric cancer patients showed that MLC was an independent prognostic factor for overall survival (odds ratio, 5.946; 95% confidence intervals, 1.524~23.197; P=0.010).

Conclusions

MLC is prognostic for survival in patients with gastric adenocarcinoma, in early gastric cancer. DND was associated with an improved prognosis compared to PND or D.

Upregulation of HOXB7 promotes the tumorigenesis and progression of gastric cancer and correlates with clinical characteristics

Several examples of aberrant homeobox gene expression have been found across a range of cancers, and it is also confirmed that homeobox genes play a critical roles in tumorigenesis and progression. Notwithstanding homeobox B7 (HOXB7) has been documented that its deregulation promotes carcinogenesis and development in gastrointestinal tract, its function in gastric cancer has not been investigated. In this study, HOXB7 expression was examined to be distinctly upregulated in gastric carcinoma GC cell lines and in the tumor relative to normal gastric tissue. High HOXB7 expression was correlated with tumor differentiation (P = 0.025) and TNM stage (P = 0.008). HOXB7 knockdown in BGC-823 and SGC-7901 resulted in decreased migration and invasion with alteration of epithelial-mesenchymal transition (EMT) proteins and influenced proliferation, apoptosis, and cell cycle. Furthermore, complementary DNA (cDNA) microarray, qPCR, and Western blotting were performed to explore potential downstream target genes of HOXB7. HOXB7 is generally overexpressed in GC, associated with patient clinical characteristics, and specifically promotes GC cell malignant biological properties through PIK3R3/AKT signaling pathways, indicating HOXB7 as a causal factor in promoting tumor progression.

Metastatic gastric cancer (MGC) patients: Can we improve survival by metastasectomy? A systematic review and meta-analysis

BACKGROUND

Prognosis with current management strategies continues to be dismal in metastatic gastric cancer (MGC) patients. We aimed to evaluate the role of metastasectomy in improving survival.

METHODS

A comprehensive search of MEDLINE, EMBASE, SCOPUS, and Cochrane central databases (1965 to present) was performed. All comparative studies measuring survival in MGC patients undergoing metastasectomy versus other therapies were included. Pooled risk ratios with corresponding 95% confidence intervals (CI) were calculated for survival at 1, 3, and 5 years.

RESULTS

Sixteen studies with 1712 patients (378 patients in metastasectomy, 1334 patients in other therapies) were eligible for the final meta-analysis. Median age was 63 years. For patients undergoing metastasectomy, a significant survival advantage was observed at 1 year (RR 0.52, CI 0.43-0.62), 3 year (RR 0.75 CI 0.67-0.83), and 5 year (RR 0.82, CI 0.74-0.91); mean increased difference in survival conferred by metastasectomy averaged between 9.3 and 15.7 months; P < 0.001 for all results. Age, ECOG status, and STROBE score did not contribute to differences in survival.

CONCLUSION

Metastasectomy is associated with increased survival at 1, 3, and 5 years in MGC patients. Large prospective randomized controlled trials are critically needed to evaluate the role of metastasectomy in MGC.

Relationship between expression of IGFBP7 and clinicopathological variables in gastric cancer

Aims

Insulin-like growth factor binding protein 7 (IGFBP7) is reported to have tumour suppressor function through an IGF-dependent pathway in various malignant tumours. However, the expression of IGFBP7 in adenocarcinoma and its relationship with tumour progression and survival differs among studies. Our aims were to investigate the relationship between the expression of IGFBP7 and clinicopathological variables and outcomes of patients with gastric cancer.

Methods

Tumour samples were obtained from 219 patients with gastric cancer who underwent gastrectomy. The expression of IGFBP7 protein was examined by immunohistochemical staining. IGFBP7 mRNA levels were analysed using real-time quantitative reverse-transcriptase PCR in 24 of the gastric cancer tumours and in adjacent non-tumour tissues. Correlation of IGFBP7 expression with clinicopathological features was analysed.

Results

The protein expression of IGFBP7 was positively correlated with depth of invasion, lymph node metastasis, distant metastasis or recurrence and pathological stage. High expression of IGFBP7 protein was associated with a significantly worse disease-specific survival (p<0.001) and was an independent prognostic factor in multivariable analysis (HR, 4.8; 95% CI 2.1 to 10.6; p<0.001). The IGFBP7 mRNA level was significantly higher in advanced gastric cancer than in early gastric cancer, in tumours with lymph node metastasis than in tumours without lymph node metastasis, and in tumours with distant metastasis or recurrence than in tumours without distant metastasis or recurrence.

Conclusions

Overexpression of IGFBP7 was associated with tumour progression and poor survival in gastric cancer. IGFBP7 may play a role in tumour progression in gastric cancer.

Licochalcone A-induced human gastric cancer BGC-823 cells apoptosis by regulating ROS-mediated MAPKs and PI3K/AKT signaling pathways

Both phosphatidylinositol 3-kinase (PI3K)/AKT and mitogen activated protein kinase (MAPK) signaling cascades play an important role in cell proliferation, survival, angiogenesis, and metastasis of tumor cells. In the present report, we investigated the effects of licochalcone A (LA), a flavonoid extracted from licorice root, on the PI3K/AKT/mTOR and MAPK activation pathways in human gastric cancer BGC-823 cells. LA increased reactive oxygen species (ROS) levels, which is associated with the induction of apoptosis as characterized by positive Annexin V binding and activation of caspase-3, and cleavage of poly-ADP-ribose polymerase (PARP). Inhibition of ROS generation by N-acetylcysteine (NAC) significantly prevented LA-induced apoptosis. Interestingly, we also observed that LA caused the activation of ERK, JNK, and p38 MAPK in BGC-823 cells. The antitumour activity of LA-treated BGC-823 cells was significantly distinct in KM mice in vivo. All the findings from our study suggest that LA can interfere with MAPK signaling cascades, initiate ROS generation, induce oxidative stress and consequently cause BGC cell apoptosis.

Update on metastatic gastric and esophageal cancers

Cancers of the stomach and esophagus are among the most challenging cancers of the GI tract to treat, associated with poor median survivals for metastatic disease and significant, sometimes prolonged, deteriorations in patient performance status as the diseases progress. However, in the past decade, we have begun to better understand disease biology and carcinogenesis, leading to the identification of subtypes of these diseases. There is also an increasing awareness of the global heterogeneity of disease and its impact on drug development. Our improved understanding of the molecular underpinnings of gastric and esophageal cancers has been accompanied with the development of novel therapeutic strategies. Recent actively investigated targets in this disease include human epidermal growth factor receptor 2, angiogenesis, MET, and immune checkpoint inhibition, with approvals of two new targeted agents, trastuzumab and ramucirumab. Improvements in our ability to deliver cytotoxic therapy, which is better tolerated and allows patients an opportunity to benefit from second- and more advanced lines of therapy, have also been observed. In this review, the current state-of-the-art management of advanced and metastatic gastric and esophageal adenocarcinomas, specifically highlighting the development of targeted therapies in these diseases, is described.

Establishment and characterization of GCSR1, a multi-drug resistant signet ring cell gastric cancer cell line

Signet ring cell gastric cancer (SRCGC) has very poor prognosis worldwide, and studying its molecular characteristics is urgent for improving the outcome. However, few well-characterized SRCGC cell lines are available for research. Therefore, we established a novel cell line GCSR1, from a Chinese male SRCGC patient. Cell morphology of GCSR1 in culture, maintained in vitro for over 90 passages, is similar to the cells from the patient. GCSR1 cells proliferated in vitro with a doubling time of 67.65 h. Karyotyping showed they were aneuploid. Missense mutation occurred in codon 193 of P53 and deletion occurred in exons 1 and 3 of P16. Results of CCK8 assay revealed that GCSR1 was more resistant to 5-fluorouracil (5-FU) and mitomycin (MMC) than other gastric cancer cell lines. Stem cell marker assay by flow cytometry showed that GCSR1 had high proportion of CD44+ and/or CD133+ cells. It formed colonies easily in soft agar and generated xenograft tumors in nude mice. In conclusion, GCSR1 is a well-established, well-characterized multi-drug resistant cell line with abundant cancer stem cells.

Molecular classification of gastric adenocarcinoma: translating new insights from the cancer genome atlas research network

Gastric cancer is a heterogenous cancer, which may be classified into several distinct subtypes based on pathology and epidemiology, each with different initiating pathological processes and each possibly having different tumor biology. A classification of gastric cancer should be important to select patients who can benefit from the targeted therapies or to precisely predict prognosis. The Cancer Genome Atlas (TCGA) study collaborated with previous reports regarding subtyping gastric cancer but also proposed a refined classification based on molecular characteristics. The addition of the new molecular classification strategy to a current classical subtyping may be a promising option, particularly stratification by Epstein-Barr virus (EBV) and microsatellite instability (MSI) statuses. According to TCGA study, EBV gastric cancer patients may benefit the programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) antibodies or phosphoinositide 3-kinase (PI3K) inhibitors which are now being developed. The discoveries of predictive biomarkers should improve patient care and individualized medicine in the management since the targeted therapies may have the potential to change the landscape of gastric cancer treatment, moreover leading to both better understanding of the heterogeneity and better outcomes. Patient enrichment by predictive biomarkers for new treatment strategies will be critical to improve clinical outcomes. Additionally, liquid biopsies will be able to enable us to monitor in real-time molecular escape mechanism, resulting in better treatment strategies.

Learning curve for EUS in gastric cancer T staging by using cumulative sum analysis

BACKGROUND

EUS is an operator-dependent procedure and requires more technical and cognitive skills than a routine endoscopic procedure. The learning curve for the staging of gastric cancer, however, has not been evaluated.

OBJECTIVE

To evaluate the threshold number of EUS examinations for gastric cancer T staging.

DESIGN

Retrospective study.

SETTING

University-affiliated tertiary care hospital in the Republic of Korea.

PATIENTS

Four trainees with no previous EUS experience.

INTERVENTION

Analyzing performance of EUS trainees in gastric cancer T staging by using cumulative sum (CUSUM) analysis.

MAIN OUTCOME MEASUREMENTS

CUSUM plot and a minimal number of procedures for reaching a plateau.

RESULTS

A total of 553 initial EUS examinations for treatment-naïve gastric cancers, performed by trainees, were enrolled in the study. The final T stage was determined by experts by using EUS in 332 gastric cancer cases, whereas the T stage of the other 221 lesions was determined by trainees by using EUS. The accuracy of EUS examinations performed by trainees and experts was 72.6% and 84.3%, respectively. The number of EUS examinations required to reach the first plateau in each trainee was 20, 41, 60, and 65.

LIMITATIONS

Retrospective study with a relatively small number of trainees.

CONCLUSION

The CUSUM scores of all of 4 trainees in the study reached a plateau by the 65th examination.

Evaluation of Trastuzumab Anti-Tumor Efficacy and its Correlation with HER-2 Status in Patient-Derived Gastric Adenocarcinoma Xenograft Models

The aim of the study was to investigate trastuzumab anti-tumor efficacy and its correlation with HER-2 status in primary xenograft models derived from Chinese patients with gastric adenocarcinoma. Patient-derived gastric adenocarcinoma xenograft (PDGAX) mouse models were firstly generated by implanting gastric adenocarcinoma tissues from patients into immune deficient mice. A high degree of histological and molecular similarity between the PDGAX mouse models and their corresponding patients’ gastric adenocarcinoma tissues was shown by pathological observation, HER-2 expression, HER-2 gene copy number, and mutation detection. Based on Hoffmann’s criteria in gastric cancer, three models (PDGAX001, PDGAX003 and PDGAX005) were defined as HER-2 positive with fluorescence in situ hybridization (FISH) amplification or immunohistochemistry (IHC) 2+/ 3+, while two models (PDGAX002, PDGAX004) were defined as HER-2 negative. Upon trastuzumab treatment, significant tumor regression (105 % TGI) was observed in model PDGAX005 (TP53 wt), while moderate sensitivity (26 % TGI) was observed in PDGAX003, and resistance was observed in PDGAX001, 002 and 004. A significant increase in HER-2 gene copy number was only observed in PDGAX005 (TP53 wt). Interestingly, trastuzumab showed no efficacy in PDGAX001 (HER2 IHC 3+ and FISH amplification, but with mutant TP53). Consistent with this finding, phosphor-HER2 modulation by trastuzumab was observed in model PDGAX005, but not in PDGAX001.

Diagnostic accuracy of endoscopic ultrasonography (EUS) for the preoperative locoregional staging of primary gastric cancer

BACKGROUND

Endoscopic ultrasound (EUS) is proposed as an accurate diagnostic device for the locoregional staging of gastric cancer, which is crucial to developing a correct therapeutic strategy and ultimately to providing patients with the best chance of cure. However, despite a number of studies addressing this issue, there is no consensus on the role of EUS in routine clinical practice.

OBJECTIVES

To provide both a comprehensive overview and a quantitative analysis of the published data regarding the ability of EUS to preoperatively define the locoregional disease spread (i.e., primary tumor depth (T-stage) and regional lymph node status (N-stage)) in people with primary gastric carcinoma.

SEARCH METHODS

We performed a systematic search to identify articles that examined the diagnostic accuracy of EUS (the index test) in the evaluation of primary gastric cancer depth of invasion (T-stage, according to the AJCC/UICC TNM staging system categories T1, T2, T3 and T4) and regional lymph node status (N-stage, disease-free (N0) versus metastatic (N+)) using histopathology as the reference standard. To this end, we searched the following databases: the Cochrane Library (the Cochrane Central Register of Controlled Trials (CENTRAL)), MEDLINE, EMBASE, NIHR Prospero Register, MEDION, Aggressive Research Intelligence Facility (ARIF), ClinicalTrials.gov, Current Controlled Trials MetaRegister, and World Health Organization International Clinical Trials Registry Platform (WHO ICTRP), from 1988 to January 2015.

SELECTION CRITERIA

We included studies that met the following main inclusion criteria: 1) a minimum sample size of 10 patients with histologically-proven primary carcinoma of the stomach (target condition); 2) comparison of EUS (index test) with pathology evaluation (reference standard) in terms of primary tumor (T-stage) and regional lymph nodes (N-stage). We excluded reports with possible overlap with the selected studies.

DATA COLLECTION AND ANALYSIS

For each study, two review authors extracted a standard set of data, using a dedicated data extraction form. We assessed data quality using a standard procedure according to the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) criteria. We performed diagnostic accuracy meta-analysis using the hierarchical bivariate method.

MAIN RESULTS

We identified 66 articles (published between 1988 and 2012) that were eligible according to the inclusion criteria. We collected the data on 7747 patients with gastric cancer who were staged with EUS. Overall the quality of the included studies was good: in particular, only five studies presented a high risk of index test interpretation bias and two studies presented a high risk of selection bias.For primary tumor (T) stage, results were stratified according to the depth of invasion of the gastric wall. The meta-analysis of 50 studies (n = 4397) showed that the summary sensitivity and specificity of EUS in discriminating T1 to T2 (superficial) versus T3 to T4 (advanced) gastric carcinomas were 0.86 (95% confidence interval (CI) 0.81 to 0.90) and 0.90 (95% CI 0.87 to 0.93) respectively. For the diagnostic capacity of EUS to distinguish T1 (early gastric cancer, EGC) versus T2 (muscle-infiltrating) tumors, the meta-analysis of 46 studies (n = 2742) showed that the summary sensitivity and specificity were 0.85 (95% CI 0.78 to 0.91) and 0.90 (95% CI 0.85 to 0.93) respectively. When we addressed the capacity of EUS to distinguish between T1a (mucosal) versus T1b (submucosal) cancers the meta-analysis of 20 studies (n = 3321) showed that the summary sensitivity and specificity were 0.87 (95% CI 0.81 to 0.92) and 0.75 (95% CI 0.62 to 0.84) respectively. Finally, for the metastatic involvement of lymph nodes (N-stage), the meta-analysis of 44 studies (n = 3573) showed that the summary sensitivity and specificity were 0.83 (95% CI 0.79 to 0.87) and 0.67 (95% CI 0.61 to 0.72), respectively.Overall, as demonstrated also by the Bayesian nomograms, which enable readers to calculate post-test probabilities for any target condition prevalence, the EUS accuracy can be considered clinically useful to guide physicians in the locoregional staging of people with gastric cancer. However, it should be noted that between-study heterogeneity was not negligible: unfortunately, we could not identify any consistent source of the observed heterogeneity. Therefore, all accuracy measures reported in the present work and summarizing the available evidence should be interpreted cautiously. Moreover, we must emphasize that the analysis of positive and negative likelihood values revealed that EUS diagnostic performance cannot be considered optimal either for disease confirmation or for exclusion, especially for the ability of EUS to distinguish T1a (mucosal) versus T1b (submucosal) cancers and positive versus negative lymph node status.

AUTHORS' CONCLUSIONS

By analyzing the data from the largest series ever considered, we found that the diagnostic accuracy of EUS might be considered clinically useful to guide physicians in the locoregional staging of people with gastric carcinoma. However, the heterogeneity of the results warrants special caution, as well as further investigation for the identification of factors influencing the outcome of this diagnostic tool. Moreover, physicians should be warned that EUS performance is lower in diagnosing superficial tumors (T1a versus T1b) and lymph node status (positive versus negative). Overall, we observed large heterogeneity and its source needs to be understood before any definitive conclusion can be drawn about the use of EUS can be proposed in routine clinical settings.

Association of variants in genes encoding for macrophage-related functions with clinical outcome in patients with locoregional gastric cancer

BACKGROUND

Nuclear factor-kappaB (NF-κB) and CCL2/CCR2 chemokine axis play a central role in tumor progression such as stimulation of angiogenesis, acceleration of tumor invasion and migration, and suppression of innate immunosurveillance in the macrophage-related functions. There have been few reports regarding association of the macrophage function-related genes with the clinical outcome in gastric cancer. We hypothesized that variants in genes encoding for NF-κB and CCL2/CCR2 axis may predict prognosis in gastric cancer and tested whether the functional single-nucleotide polymorphisms (SNPs) will be associated with clinical outcome in patients with gastric cancer across two independent groups.

PATIENTS AND METHODS

This study enrolled two cohorts which consisted of 160 Japanese patients and 104 US patients with locoregional gastric cancer. Genomic DNA was analyzed for association of 11 SNPs in NFKB1, RELA, CCL2, and CCR2 with clinical outcome using PCR-based direct DNA sequencing.

RESULTS

The univariable analysis showed four SNPs had significant association with clinical outcome in the Japanese cohort, NFKB1 rs230510 remained significant upon multivariable analysis. The patients with the A allele of the NFKB1 rs230510 had significantly longer overall survival (OS) compared with those with the T/T genotype in both the Japanese and US cohort in the univariable analysis. In contrast, genotypes with the T allele of CCL2 rs4586 were significantly associated with shorter OS compared with the C/C genotype in the US cohort [hazard ratio (HR) 2.43; P = 0.015] but longer OS in the Japanese cohort (HR 0.58; P = 0.021), resulting in the statistically significant opposite impact on OS (P = 0.001).

CONCLUSIONS

Our study provides the first evidence that the NFKB1 rs230510 and CCL2 rs4586 are significantly associated with the clinical outcome in patients with locoregional gastric cancer. These results also suggest that the genetic predisposition of the host may dictate the immune-related component of the tumor for progression in gastric cancer.

Capecitabine metronomic chemotherapy inhibits the proliferation of gastric cancer cells through anti-angiogenesis

To evaluate the inhibitory effect and mechanism of capecitabine metronomic chemotherapy on gastric cancer cells. In vitro, the effects of 5-fluorouracil (Fu) metronomic chemotherapy on proliferation, apoptosis, tube formation ability, and angiogenesis were detected. In vivo, Ki-67, CD34 and VEGF were detected by immunohistochemical staining (IHC). Flow cytometry was used to detect the percentage of circulating endothelial progenitors (CEPs), and VEGF and PDGF were detected by ELISA in the peripheral blood of nude mice. The proliferation of the SGC-7901 and AGS gastric cancer cell lines in the metronomic 5-Fu group was decreased compared with the control group in vitro. The total length of the small tubes and tubular junction numbers were significantly lower in the metronomic group than the control group. The VEGF and PDGF levels in the cell culture supernatants were lower in the metronomic group than the control group. Compared with the control group, the CEP percentage was decreased in the peripheral blood of tumor-bearing nude mice following treatment with metronomic 5-Fu or capecitabine chemotherapy. No significant changes were found in the conventional or control group. In the peripheral blood of tumor-bearing nude mice, the VEGF and PDGF levels were decreased in the metronomic groups. Metronomic 5-Fu inhibited the proliferation of gastric cancer cells in vitro and in vivo, and their antitumor effects were non-inferior to those of conventional dose chemotherapy, with mild side effects. Thus, tumor inhibition may be attributed to anti-angiogenesis.

The downregulation of miR-200c/141 promotes ZEB1/2 expression and gastric cancer progression

Gastric cancer is the fourth most common malignancy in the world. Although microRNA-200 (miR-200) family members are thought to play roles in tumorigenesis, their functions in carcinogenesis are tumor specific, and the underlying mechanism of action still remains elusive. Few studies to date have addressed the dysregulation and function of miR-200 family members in gastric cancer progression. Here, we report that the miR-200 family members, miR-200c and miR-141, were significantly downregulated in gastric cancer specimens and gastric cancer cell lines. Importantly, on clinical samples, the expression of miR-200c and miR-141 was inversely correlated with TNM stage, tumor invasion depth (T), tumor embolus and disease-free survival. Wound-healing assay results showed that co-transfected miR-200c/141 could inhibit the migration and invasion capability of the gastric cell line SGC-7901. We also found that miR-200c and miR-141 directly targeted zinc finger E-box-binding homeobox 1/2 (ZEB1/2) and upregulated E-cadherin expression. In specimens from gastric cancer patients, reduced expression of miR-200c/141 was associated with increased expression of ZEB1 and/or ZEB2. In addition, the downregulation of miR-200c and miR-141 was found to be due to a highly methylated CpG island located upstream of their genomic sequence and/or upregulated TGF-β signaling. Treatment with the chemotherapeutic agent decitabine, a known DNA methyltransferase inhibitor, increased miR-200c/141 expression and ameliorated decreased expression of miR-200c/141 induced by TGF-β in SGC-7901 cells. Our study revealed that miR-200c/141 was downregulated by CpG island methylation and TGF-β signaling, which decreased ZEB1/2 expression and increased E-cadherin expression to inhibit migration and invasion of gastric cancer cells and provides powerful evidence for the application of decitabine in gastric cancer treatment.

Urushiol Induces Apoptosis via a p53-dependent Pathway in Human Gastric Cancer Cells

BACKGROUND

Urushiols are mixtures of olefinic catechols which is isolated from the sap of Korean lacquer tree (Rhus vernicifera Stokes). The aim of this study was to determine the anticancer effects of urushiol in human gastric adenocarcinoma cell lines.

METHODS

The cytotoxicity of urushiols was assessed by MTT assays on the two gastric adenocarcinoma cell lines, MKN-45 (wild type of p53) and MKN-28 (mutant type of p53). We also examined the action mechanisms of urushiol by analyzing its effects on cell cycle progression and apoptosis induction.

RESULTS

The cytotoxic results from MTT assays indicated that urushiol inhibited human gastric cancer cell growth in a dose-dependent manner, with IC50 values of approximately 15 and 20 μg/ml on MKN-45 and MKN-28 cells, respectively. Urushiol mediated cell death on these two cancer cell lines through different pathways. Urushiol induced apoptosis on MKN-45 cells, concomitant with apoptotic nuclear change, DNA fragmentation, poly (ADP-ribose) polymerase cleavage and apoptotic body formation via extrinsic pathway of apoptosis. However, no apoptotic features were induced by urushiol treatment on MKN-28 cells. Urushiol induced cytostatic cell growth inhibition via upregulation of the cyclin-dependent kinase inhibitors, p21 (WAF1/CIP1) and p27 (KIP1) proteins and down-regulation of cyclin-dependent kinase 2 and 4 proteins in a p53-independent manner.

CONCLUSIONS

These data provide evidence that urushiol has the potential to be used as a chemotherapeutic agent in human gastric cancer.

Curcumin induced human gastric cancer BGC-823 cells apoptosis by ROS-mediated ASK1-MKK4-JNK stress signaling pathway

The signaling mediated by stress-activated MAP kinases (MAPK), c-Jun N-terminal kinase (JNK) has well-established importance in cancer. In the present report, we investigated the effects of curcumin on the signaling pathway in human gastric cancer BGC-823 cells. Curcumin induced reactive oxygen species (ROS) production and BGC-823 cells apoptosis. Inhibition of ROS generation by antioxidant (NAC or Trion) significantly prevented curcumin-mediated apoptosis. Notably, we observed that curcumin activated ASK1, a MAPKKK that is oxidative stress sensitive and responsible to phosphorylation of JNK via triggering cascades, up-regulated an upstream effector of the JNK, MKK4, and phosphorylated JNK protein expression in BGC-823 cells. However, curcumin induced ASK1-MKK4-JNK signaling was attenuated by NAC. All the findings confirm the possibility that oxidative stress-activated ASK1-MKK4-JNK signaling cascade promotes the apoptotic response in curcumin-treated BGC-823 cells.

The role of hepatectomy in the management of metastatic gastric adenocarcinoma: a systematic review

BACKGROUND

Gastric cancer has a high mortality, with many patients presenting with advanced disease. Many patients who undergo curative gastrectomy will subsequently develop metastatic disease. Hepatectomy has an established place in treating metastases from a variety of cancers but its role in gastric cancer is not clear. This review sought to systematically appraise the literature to establish the role of hepatectomy in treating gastric cancer metastases.

METHOD

Medline and EMBASE were searched for all papers publishing data on survival of patients with metastatic gastric adenocarcinoma who underwent hepatectomy.

RESULTS

Seventeen studies with 438 patients were included. There were no randomised controlled trials. Perioperative mortality was 2%, with morbidity between 17 and 60%. Patients with solitary metastases appeared to have better survival. Other favourable survival characteristics included unilobar disease, and metachronous presentation. No advantage was demonstrated with either adjuvant or neoadjuvant chemotherapy.

DISCUSSION

Few patients with hepatic metastases from gastric cancer are suitable for hepatectomy, but for those suitable there appears to be survival benefit. Patients with synchronous, multiple or bilobar metastases have worse survival.

CONCLUSION

The evidence supporting the role of hepatectomy in the treatment of hepatic metastases from gastric cancer is weak. However in a selected group there appears to be a survival advantage; patients with solitary metastases had better survival outcomes than those with multiple metastases and metachronous presentation was associated with a better prognosis than synchronous presentation. Hepatectomy should be considered in these patients in the setting of a randomised trial.

Neoadjuvant Therapy of Gastric Cancer: A Decisive Step Forward

BACKGROUND

Although its incidence has been steadily decreasing in Western countries, gastric cancer remains a leading cause of cancer deaths worldwide. The detection rate of early-stage cancers is improving; nevertheless, the majority of cases is still diagnosed at later stages with a poor prognosis. Furthermore, the results that can be achieved with surgery have reached a plateau of effectiveness.

SUMMARY

Neoadjuvant chemotherapy was successfully introduced first in patients with non-curatively resectable disease. In the last decade, neoadjuvant chemotherapy has also been established in potentially curatively resectable cases and has become the state-of-the-art treatment. Esophagogastric junction (EGJ) tumors are not optimally treated with chemotherapy alone, and combined radiochemotherapy (RCT) seems to yield superior outcomes.

KEY MESSAGE

The use of neoadjuvant therapy has been successfully established in patients with curatively resectable disease. Neoadjuvant chemotherapy is now a cornerstone in the treatment of gastric cancer and cancer of the EGJ, although further work is needed in order to define the optimal combination regimen.

PRACTICAL IMPLICATIONS

Neoadjuvant chemotherapy is currently the gold standard for the treatment of gastric cancer and cancer of the EGJ. Several independent studies have shown the benefits of using combination regimens that included cisplatin and 5-fluorouracil, though recently the use of the EOX (epirubicin, oxaliplatin and capecitabine) regimen has been widely accepted in this setting. Tumors of the EGJ benefit from neoadjuvant treatment with combined RCT. It should be noted that the optimal neoadjuvant regimen in EGJ tumors has not yet been defined, and the survival advantage of neoadjuvant RCT over neoadjuvant chemotherapy remains to be established in this patient population.

Imagine a world without cancer

Background

Since the “War on Cancer” was declared in 1971, the United States alone has expended some $300 billion on research, with a heavy focus on the role of genomics in anticancer therapy. Voluminous data have been collected and analyzed. However, in hindsight, any achievements made have not been realized in clinical practice in terms of overall survival or quality of life extended. This might be justified because cancer is not one disease but a conglomeration of multiple diseases, with widespread heterogeneity even within a single tumor type.

Discussion

Only a few types of cancer have been described that are associated with one major signaling pathway. This enabled the initial successful deployment of targeted therapy for such cancers. However, soon after this targeted approach was initiated, it was subverted as cancer cells learned and reacted to the initial treatments, oftentimes rendering the treatment less effective or even completely ineffective. During the past 30 plus years, the cancer classification used had, as its primary aim, the facilitation of communication and the exchange of information amongst those caring for cancer patients with the end goal of establishing a standardized approach for the diagnosis and treatment of cancers. This approach should be modified based on the recent research to affect a change from a service-based to an outcome-based approach. The vision of achieving long-term control and/or eradicating or curing cancer is far from being realized, but not impossible. In order to meet the challenges in getting there, any newly proposed anticancer strategy must integrate a personalized treatment outcome approach. This concept is predicated on tumor- and patient-associated variables, combined with an individualized response assessment strategy for therapy modification as suggested by the patient’s own results. As combined strategies may be outcome-orientated and integrate tumor-, patient- as well as cancer-preventive variables, this approach is likely to result in an optimized anticancer strategy.

Summary

Herein, we introduce such an anticancer strategy for all cancer patients, experts, and organizations: Imagine a World without Cancer.

Leucine-rich repeat-containing G-protein-coupled receptor 5 is associated with invasion, metastasis, and could be a potential therapeutic target in human gastric cancer

Background:

Leucine-rich repeat-containing G-protein-coupled receptor 5 (Lgr5), which is identified as a novel intestinal stem cell marker, is overexpressed in various tumours. In this study, we explore Lgr5 expression in gastric carcinoma and analyse its role in invasion, metastasis, and prognosis in carcinoma.

Methods:

A combination of immunohistochemistry, western blotting, and quantitative reverse transcription–polymerase chain reaction were used to detect mRNA and protein expression levels of Lgr5 and matrix metalloproteinase 2 (MMP2). Small interfering RNA against Lgr5 was designed, synthesised, and transfected into AGS cells. The effects of Lgr5 siRNA on cell invasion were detected by transwell invasion chamber assay and wound healing assay.

Results:

Leucine-rich repeat-containing G-protein-coupled receptor 5 expression was significantly higher in gastric carcinomas than in normal mucosa. Leucine-rich repeat-containing G-protein-coupled receptor 5 expression positively correlated with the depth of invasion, lymph node metastasis, distance of metastasis, and MMP2 expression levels. Multivariate analysis showed that Lgr5 had an independent effect on survival, and that it positively correlated with MMP2. Leucine-rich repeat-containing G-protein-coupled receptor 5 siRNAs inhibited Lgr5 mRNA and protein expression. Transwell assays indicated that these siRNAs resulted in significantly fewer cells migrating through the polycarbonate membrane, and wound healing assay also indicated that siRNAs decreased the migration of cells. Inhibition of Lgr5 resulted in a significant decrease in MMP2 and β-catenin levels compared with those in controls.

Conclusions:

Leucine-rich repeat-containing G-protein-coupled receptor 5 was correlated with invasion and metastasis. Leucine-rich repeat-containing G-protein-coupled receptor 5 inhibition could serve as a novel therapeutic approach.

Long non-coding RNA GHET1 promotes gastric carcinoma cell proliferation by increasing c-Myc mRNA stability

Long non-coding RNAs (lncRNAs), a recently characterized class of non-coding RNAs, have been shown to have important regulatory roles and are de-regulated in a variety of tumors. However, the contributions of lncRNAs to gastric carcinoma and their functional mechanisms remain largely unknown. In this study, we found that lncRNA gastric carcinoma high expressed transcript 1 (lncRNA-GHET1) was up-regulated in gastric carcinoma. The over-expression of this lncRNA correlates with tumor size, tumor invasion and poor survival. Gain-of-function and loss-of-function analyses demonstrated that GHET1 over-expression promotes the proliferation of gastric carcinoma cells in vitro and in vivo. Knockdown of GHET1 inhibits the proliferation of gastric carcinoma cells. RNA pull-down and immunoprecipitation assays confirmed that GHET1 physically associates with insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1) and enhances the physical interaction between c-Myc mRNA and IGF2BP1, consequently increasing the stability of c-Myc mRNA and expression. The expression of GHET1 and c-Myc is strongly correlated in gastric carcinoma tissues. Depletion of c-Myc abolishes the effects of GHET1 on proliferation of gastric carcinoma cells. Taken together, these findings indicate that GHET1 plays a pivotal role in gastric carcinoma cell proliferation via increasing c-Myc mRNA stability and expression, which suggests potential use of GHET1 for the prognosis and treatment of gastric carcinoma.

Ramucirumab: targeting angiogenesis in the treatment of gastric cancer

Gastroesophageal cancer is responsible for over 1 million deaths annually worldwide; for patients with advanced disease treatment options are limited. Angiogenesis is an attractive therapeutic target that has been successfully exploited in other cancers. Ramucirumab, a fully humanized monoclonal antibody targeting VEGFR-2 has demonstrated efficacy as a single agent and in combination with paclitaxel in two large randomized trials (REGARD and RAINBOW) for the treatment of advanced previously treated gastroesophageal cancer. In combination with paclitaxel chemotherapy ramucirumab treated patients demonstrated increased rates of neutropenia, and ramucirumab is also associated with hypertension consistent with other antiangiogenic agents. Ramucirumab has been US FDA approved for patients with advanced gastroesophageal cancer who have progressed during or after treatment with fluoropyrimidine- or platinum-containing chemotherapy.

New directions in perioperative management of locally advanced esophagogastric cancer

Cancers of the esophagus arise as adenocarcinomas and squamous cell carcinomas; these represent distinct diseases, with differing prognosis, yet they are often studied in common trials. With surgery alone, 5 year survival for T2-T3N0 disease is less than 30% to 40%, and declines to less than 25% with nodal involvement. The CROSS randomly assigned patients to surgery alone or to weekly carboplatin/paclitaxel X 5 and 41.4 Gy concurrent radiotherapy, followed by surgery. Seventy-five percent of enrolled patients had adenocarcinoma. Preoperative combined-modality therapy improved R0 resection from 69% to 92% (p &lt; 0.001 and improved median survival from 24 months to 49.4 months (p &lt; 0.003). This regimen reduced both locoregional recurrence (34% to 14%; p &lt; 0.001) and the development of peritoneal carcinomatosis (14% to 4%; p &lt; 0.001). Systemic perioperative therapy may have a greater effect on distant disease, the predominant mode of failure for these patients, and current trials compare preoperative chemoradiation with periooperative systemic therapy. PET scan response during preoperative chemotherapy without radiotherapy correlates with improvements in pathologic response and with improved survival. Nonresponse on early PET scan allows identifıcation of patients for earlier surgery and discontinuation of ineffective preoperative chemotherapy, without survival detriment. There is no predictive benefıt for early PET scan during the course of chemotherapy followed by chemoradiotherapy. The use of early PET scan during induction chemotherapy is being evaluated in CALGB/Alliance trial (NCT01333033). Molecular profıling has identifıed somatic gene mutations and pathways that may be oncogenic in upper gastrointestinal cancers. Potential targets include the epidermal growth factor receptor (EGFR), vascular endothelial growth factor receptor (VEGFR), HER2, mammalian target of rapamycin (mTOR), fıbroblast growth factor receptor (FGFR), MEK, and others. Targeted therapies with known survival benefit in esophagogastric cancer are currently limited to trastuzumab for HER2 overexpressing cancers, or ramicirumab.

A pilot study assessing the incidence and clinical significance of circulating tumor cells in esophagogastric cancers

BACKGROUND

Circulating tumor cells (CTCs) have been found to be of clinical utility in predicting response to treatment and prognosis in several malignancies. Less is known of the prevalence and clinical relevance of CTCs in esophagogastric adenocarcinoma, with the available data arising from heterogeneous patient populations using varied detection methods.

PATIENTS AND METHODS

A pilot study was undertaken to assess the prevalence of CTCs in patients with advanced esophageal or gastric adenocarcinoma. Patients were eligible if they had advanced disease and either had received no prior therapy or had progressed after prior chemotherapy. Blood samples for CTC analysis were obtained at baseline and during the course of treatment. The CellSearch immunomagnetic CTC detection platform was used.

RESULTS

Twenty-two patients with metastatic esophageal or gastric adenocarcinoma were enrolled. Eighteen received first-line EOX (epirubicin/oxaliplatin/capecitabine) chemotherapy (± panitumumab) and had baseline samples suitable for CTC analysis. At baseline, ≥ 2 CTCs were detected in 8 patients (44%). Overall tumor response rate was 60% in patients with < 2 CTCs and 37.5% in patients with ≥ 2 CTCs. Median progression-free and overall survival were 6.1 and 10.5 months and 5.2 and 6.1 months in the groups of patients with < 2 CTCs and ≥ 2 CTCs, respectively. The study was prematurely discontinued, owing to the withdrawal of commercial support.

CONCLUSION

The incidence of CTCs in locally advanced or metastatic esophagogastric cancer may be clinically relevant. Investigation of the potential clinical utility of CTCs is warranted in a larger cohort of patients with esophagogastric cancer.