Neoadjuvant treatment for gastric cancer

LncRNA LIFR-AS1 promotes proliferation and invasion of gastric cancer cell via miR-29a-3p/COL1A2 axis

BACKGROUND

LncRNA was known to be closely associated with the progression of human tumors. The role of lncRNA LIFR-AS1 in the pathogenesis and progression of gastric tumor is still unclear. The aim of this study was to investigate the function of LIFR-AS1 and the underlying mechanism in the pathogenesis and progression of gastric cancer.

METHODS

QRT-PCR was used to evaluate the expression of LIFR-AS1, miR-29a-3p and COL1A2 in gastric tumor tissues and cells. Western blotting was used to evaluate the protein expression of COL1A2 in gastric tumor cells. CCK-8 assay, transwell assay and flow cytometry were used to evaluate the roles of LIFR-AS1, miR-29a-3p and COL1A2 in cell proliferation, invasion, migration and apoptosis. The relationship among LIFR-AS1, miR-29a-3p and COL1A2 was assessed by bioinformatics analyses and luciferase reporter assay.

RESULTS

The expression levels of LIFR-AS1 were significantly increased in gastric tumor tissues and cells, while the expression levels of miR-29a-3p were decreased. The expression of miR-29a-3p was negatively correlated with the expression of LIFR-AS1 in gastric cancer tumor tissues. Knocking down of LIFR-AS1 inhibited proliferation, invasion and migration of gastric tumor cells, and induced apoptosis of gastric tumor cells. Bioinformatics analyses and integrated experiments revealed that LIFR-AS1 elevated the expression of COL1A2 through sponging miR-29a-3p, which further resulted in the progression of gastric tumor.

CONCLUSION

LIFR-AS1 plays an important role as a competing endogenous RNA in gastric tumor pathogenesis and may be a potential target for the diagnosis and treatment of gastric tumor.

Neoadjuvant chemoradiotherapy for locally advanced gastric cancer with bulky lymph node metastasis: Five case reports

BACKGROUND

Neoadjuvant chemoradiotherapy (NACRT) has not been accepted as a general therapy for gastric cancer because of its localized effect and toxicity for radiosensitive organs. However, if radiation therapy could compensate for the limited or inadequate treatment choices available for elderly patients and/or those at high risk, the available therapeutic options for advanced gastric cancer might increase. From this perspective, we present our experiences of five patients with advanced gastric cancer in whom we used NACRT therapy with interesting results.

CASE SUMMARY

We admitted five patients with clinical Stage III gastric cancer and bulky lymph node metastasis or adjacent organ invasion at the time of diagnosis. A total of 50 Gy of preoperative intensity modulated radiation therapy was delivered to the patients in doses of 2.0 Gy/d, together with a regimen of concomitant chemotherapy comprising two courses of oral tegafur/gimeracil/oteracil (S-1; 65 mg/m2 per day) for three consecutive weeks followed by two weeks of rest, starting at the same time as radiotherapy. All patients underwent no residual tumor resection and a pathological complete response of the primary tumors was achieved in two patients. The incidence of hematological toxicity was low, although the digestive toxicities of anorexia and diarrhea developed in three of the five patients, necessitating termination of radiation therapy at 30 Gy and S-1 at three weeks. However, even 30 Gy of irradiation and half the dose of S-1 resulted in sufficient downstaging, indicating that even a reduced amount of NACRT could confer considerable effects.

CONCLUSION

Slightly reduced NACRT might be useful and safe for patients with locally advanced gastric cancer.

Quality of life as a fundamental outcome after curative intent gastrectomy for adenocarcinoma: lessons learned from patients

Background

Gastric cancer has an important epidemiologic impact, and the main curative therapeutic modality for gastric cancer is surgical resection. However, even curative intent therapy can have negative effects on the quality of life (QoL) of these patients, which is undesirable; thus, it is difficult to balance the standardized treatment reported in the literature and treatment response to achieve full patient satisfaction. The purpose of our study was to evaluate the QoL and identify the association of scores on the Functional Assessment of Cancer Therapy-Gastric (FACT-Ga) and Short Form 36 Health Survey version 2 (SF36v2) questionnaires with sociodemographic, clinical and anatomopathological aspects of gastric adenocarcinoma patients undergoing curative surgery.

Methods

This was a cross-sectional study involving 104 patients from three regions of Brazil. Inferential analyses were used to compare (multiple regression and Mann-Whitney or Kruskal-Wallis tests) the relationships between these scores and variables (Spearman's coefficient).

Results

In the multiple regression analysis, we found correlations between Helicobacter pylori status and physical well-being (PWB) (P=0.026), between gender and emotional well-being (EWB) (P=0.008), between Lauren's histology and physical functioning (P=0.009), as well as the Short Form 36 Health Survey version 2 (SF-36v2) role-physical (P=0.027), between the tumor site and EWB (P=0.038), between the SF-36v2 mental health and N (the lower the staging, the better the score, P=0.006) and between the SF-36v2 mental health and lymph nodes removed (P=0.029). According to the Mann-Whitney or Kruskal-Wallis test, women had worse FACT-Ga total (P=0.049), PWB (P=0.005), EWB (P=0.007), gastric cancer subscale (GaCS, P=0.011), trial outcome index (TOI, P=0.030) and mental health scores than men (P=0.011). Patients with distal tumors had better scores (FACT-Ga, P=0.018; GaCS, P=0.014; TOI, P=0.020) than patients with proximal tumors. Patients with tumors located in the cardia had better physical functioning than those with proximal tumors (P=0.042). Patients who underwent partial gastrectomy had better FACT-Ga total scores (P=0.011), PWB (P=0.033), GaCS scores (P=0.006) and TOI scores (P=0.008) than those who underwent total gastrectomy. Patients who did not receive adjuvant therapy had worse bodily pain as reported on the SF-36v2 than those who received therapy (P=0.048). According to Spearman's coefficient, a higher lymph node stage corresponded to worse FACT-Ga total (s=-0.200, P=0.034), GaCS (s=-0.206, P=0.037), TOI (s=-0.216; P=0.028) and vitality (s=-0.215, P=0.029) scores. A longer time after treatment corresponded to a better SF-36v2 role-physical domain score (s=0.223; P=0.023).

Conclusions

The type of treatment instituted, postoperative time and sociodemographic and anatomopathological factors influence the QoL.

Treatment in resectable non-metastatic adenocarcinoma of stomach: Changing paradigms

Adjuvant treatment in gastric adenocarcinoma has been a challenge for the treating specialists, and despite several trials, a clear consensus is yet to be defined. The higher propensity for lymph nodal involvement and locoregional recurrences led to the hypothesis that locoregional and systemic treatments need to be equally aggressive to achieve better outcomes in the management of gastric adenocarcinoma. Regional, ethnic, and biological differences between the Eastern and Western population are also found to reflect in the tumor behavior and its response to treatment. The MAGIC (Medical Research Council Adjuvant Gastric Infusional Chemotherapy), Intergroup 0116, ACTS-GC (Adjuvant Chemotherapy Trial of S-1 for Gastric Cancer), CLASSIC (Capecitabine and Oxaliplatin Adjuvant Study in Stomach Cancer), ARTIST (Adjuvant Chemoradiation Therapy in Stomach Cancer), and the recently published CRITICS (Chemoradiotherapy after Induction Chemotherapy in Cancer of the Stomach) trials were a few of the randomized controlled trials that tried to give a clearer perspective of this tumor, though it still remains a dilemma. A study incorporating the tumor and demographic factors along with the availability of skilled talent and resources might generate an answer.

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.

MicroRNA-200c regulates cisplatin resistance by targeting ZEB2 in human gastric cancer cells

This study was specifically designed to confirm the hypothesis that microRNA-200c (miR-200c) affects the development of cisplatin (DDP) resistance in human gastric cancer cells by targeting zinc finger E-box binding homeobox 2 (ZEB2). A total of 50 gastric cancer tissues and their corresponding normal adjacent tissue samples were collected. Then, the expression levels of miR-200c and ZEB2 in both gastric cancer specimens and cells were detected using the quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) and immunohistochemical methods. A dual‑luciferase reporter gene assay was conducted to evaluate the effect of miR-200c on the 3'-untranslated region (3'UTR) luciferase activity of ZEB2. SGC7901/DDP cells were transfected with miR-200c mimics and ZEB2 siRNA, respectively. Subsequently, changes in cellular proliferation and apoptosis were detected through the methyl thiazolyl tetrazolium assay and flow cytometric analysis, respectively. We also carried out a western blot analysis assay in order to detect the expression of apoptosis-related genes and ZEB2. miR-200c was significantly downregulated and ZEB2 was significantly upregulated in both gastric cancer tissues and SGC7901/DDP cells when compared with those in normal tissues and SGC7901 cells (P<0.01). The dual luciferase reporter gene assay showed that miR-200c could specifically bind with the 3'UTR of ZEB2 and significantly suppress the luciferase activity by 42% (P<0.01). Upregulation of miR-200c or downregulation of ZEB2 enhanced the sensitivity of SGC7901/DDP cells to DDP. miR‑200c was significantly downregulated in both gastric cancer tissues and cells, while the expression of ZEB2 exhibited the opposite trend. Our study further demonstrated that miR-200c could enhance the sensitivity of SGC7901/DDP cells to DDP through targeted regulation of ZEB2 expression in gastric cancer tissues.

Peripheral venous blood neutrophil-to-lymphocyte ratio predicts survival in patients with advanced gastric cancer treated with neoadjuvant chemotherapy

Background

Accurate and useful predictors of gastric carcinoma treated with neoadjuvant chemotherapy are lacking at present. We aim to explore the potential prognostic significance of the neutrophil-to-lymphocyte ratio (NLR) in advanced gastric cancer receiving S-1 plus oxaliplatin (SOX) or oxaliplatin and capecitabine (XELOX) regimen.

Methods

We enrolled 91 patients with advanced gastric cancer treated with neoadjuvant chemotherapy from August 2008 to September 2015. The peripheral venous blood samples were collected before neoadjuvant chemotherapy. The NLR was divided into two groups: low NLR <2.17 group and high NLR ≥2.17 group. Univariate analysis on disease-free survival (DFS) and overall survival (OS) were generated using the Kaplan–Meier method and compared using the log-rank test. Prognostic factors were assessed by univariate analyses, and the independent prognostic factors were evaluated using multivariate analysis (Cox’s proportional-hazards regression model).

Results

The univariate analysis showed that median DFS and median OS were worse for high NLR values than low NLR values before neoadjuvant chemotherapy (median DFS: 19.97 and 26.87 months, respectively, P=0.299; median OS: 25.83 and 29.73 months, respectively, P=0.405). Multivariate analysis showed that the NLR before neoadjuvant chemotherapy was not an independent prognostic factor for DFS and OS. However, median DFS and median OS were worse for high neutrophil values than for low neutrophil values (median DFS: 21.03 and 26.87 months, respectively, P=0.396; median OS: 24.43 and 29.37 months, respectively, P=0.534); for low lymphocyte values than for high lymphocyte values before neoadjuvant chemotherapy (median DFS: 22.33 and 26.87 months, respectively, P=0.624; median OS: 26.37 and 27.93 months, respectively, P=0.584). Nevertheless, patients with low NLR had better 1-year, 3-year, and 5-year DFS and OS rates.

Conclusion

NLR may serve as a cheap and convenient prognostic indicator in gastric carcinoma patients receiving SOX or XELOX neoadjuvant chemotherapy. Low NLR may help the doctors to take efficient treatment measures for gastric cancer.

Contribution of diffusion weighted MRI to diagnosis and staging in gastric tumors and comparison with multi-detector computed tomography

Background

Diagnostic performance of Diffusion-Weighted magnetic resonance Imaging (DWI) and Multi-Detector Computed Tomography (MDCT) for TNM (Tumor, Lymph node, Metastasis) staging of gastric cancer was compared.

Patients and methods

We used axial T2-weighted images and DWI (b-0,400 and b-800 s/mm2) protocol on 51 pre-operative patients who had been diagnosed with gastric cancer. We also conducted MDCT examinations on them. We looked for a signal increase in the series of DWI images. The depth of tumor invasion in the stomach wall (tumor (T) staging), the involvement of lymph nodes (nodal (N) staging), and the presence or absence of metastases (metastatic staging) in DWI and CT images according to the TNM staging system were evaluated. In each diagnosis of the tumors, sensitivity, specificity, positive and negative accuracy rates of DWI and MDCT examinations were found through a comparison with the results of the surgical pathology, which is the gold standard method. In addition to the compatibilities of each examination with surgical pathology, kappa statistics were used.

Results

Sensitivity and specificity of DWI and MDCT in lymph node staging were as follows: N1: DWI: 75.0%, 84.6%; MDCT: 66.7%, 82%;N2: DWI: 79.3%, 77.3%; MDCT: 69.0%, 68.2%; N3: DWI: 60.0%, 97.6%; MDCT: 50.0%, 90.2%. The diagnostic tool DWI seemed more compatible with the gold standard method (surgical pathology), especially in the staging of lymph node, when compared to MDCT. On the other hand, in T staging, the results of DWI and MDCT were better than the gold standard when the T stage increased. However, DWI did not demonstrate superiority to MDCT. The sensitivity and specificity of both imaging techniques for detecting distant metastasis were 100%.

Conclusions

The diagnostic accuracy of DWI for TNM staging in gastric cancer before surgery is at a comparable level with MDCT and adding DWI to routine protocol of evaluating lymph nodes metastasis might increase diagnostic accuracy.

Capecitabine plus paclitaxel induction treatment in gastric cancer patients with liver metastasis: a prospective, uncontrolled, open-label Phase II clinical study

AIM

To determine the overall survival rate, radical resection rate, objective response rate and safety of capecitabine plus paclitaxel induction chemotherapy in gastric cancer patients with liver metastases.

PATIENTS & METHODS

A total of 30 patients (median age: 59.5 years) diagnosed as gastric adenocarcinoma with liver metastasis received ≥3 cycles of capecitabine and paclitaxel therapy followed by radical resection 4-6 weeks after termination of chemotherapy.

RESULTS

The median survival time was 11.4 months, and the objective response rate was 53.3%. The radical resection rate was 23.3% (95% CI: 9.9-42.3). Major toxicities included grade 3 neutropenia (10.0%) and grade 3 diarrhea (3.3%).

CONCLUSION

Capecitabine plus paclitaxel chemotherapy may be effective and safe to improve overall survival and the resection rate of gastric cancer patients with liver metastases. ClinicalTrials.gov identifier: NCT0116704.

Chemotherapy-Induced miRNA-29c/Catenin-δ Signaling Suppresses Metastasis in Gastric Cancer

Chemotherapy has improved the survival of patients with gastric cancer by unknown mechanisms. In this study, we showed that cisplatin and docetaxel used in gastric cancer treatment increase the expression of miRNA-29 (miR-29) family members and decrease the expression of their oncogenic targets, mediating a significant part of the efficacious benefits of these chemotherapeutic agents. In particular, patients with gastric cancer who experienced recurrences after chemotherapy tended to exhibit low levels of miR-29c expression in their tumors, suggesting that miR-29c activation may contribute to the chemotherapeutic efficacy. Enforced expression of miR-29s in gastric cancer cells inhibited cell invasion in vitro and in vivo by directly targeting catenin-δ (CTNND1). Drug treatment suppressed gastric cancer cell invasion by restoring miR-29c-mediated suppression of catenin-δ and RhoA signaling. In parallel, drug treatment also activated several tumor-suppressive miRNAs, thereby decreasing expression of their oncogenic effector targets. Overall, our findings defined a global mechanism for understanding the efficacious effects of cytotoxic chemotherapy in gastric cancer.

Blood neutrophil-lymphocyte ratio predicts survival in locally advanced cancer stomach treated with neoadjuvant chemotherapy FOLFOX 4

Accurate predictors of survival for patients with advanced gastric cancer treated with neoadjuvant chemotherapy are currently lacking. In this study, we aimed to evaluate the prognostic significance of the neutrophil-lymphocyte ratio (NLR) in patients with stage III-IV gastric cancer who received neoadjuvant chemotherapy FOLFOX 4 as neoadjuvant chemotherapy. We enrolled 70 patients with stage III-IV cancer stomach in this study. Patients received FOLFOX 4 as neoadjuvant chemotherapy. Blood sample was collected before chemotherapy. The NLR was divided into two groups: high (>3) and low (≤ 3). Univariate analysis on progression-free survival (PFS) and overall survival (OS) was performed using the Kaplan-Meier and log-rank tests, and multivariate analysis was conducted using the Cox proportional hazards regression model. The toxicity was evaluated according to National Cancer Institute Common Toxicity Criteria. The univariate analysis showed that PFS and OS were both worse for patients with high NLR than for those with low NLR before chemotherapy (median PFS 28 and 44 months, respectively, P = 0.001; median OS 30 and 48 months, P = 0.001). Multivariate analysis showed that NLRs before chemotherapy were independent prognostic factors of OS but not for progression-free survival. NLR may serve as a potential biomarker for survival prognosis in patients with stage III-IV gastric cancer receiving neoadjuvant chemotherapy. The FOLFOX 4 demonstrated an acceptable toxicity.

The effects of neoadjuvant chemotherapy on resectability of locally-advanced gastric adenocarcinoma: a clinical trial

INTRODUCTION

Surgical resection is the only curative treatment for gastric cancer. However, the overall prognosis of gastric adenocarcinoma is poor and advanced disease may even make surgical treatment impossible. It has been theoretically proposed that administration of chemotherapy before surgical resection may down-stage the disease state and facilitate resectability especially in locally-advanced tumors.

AIM

We wanted to assess the effect of administration of neoadjuvant chemotherapy on tumor resectability in patients with locally-advances gastric adenocarcinoma.

MATERIALS AND METHODS

During a randomized-controlled trial, we divided 60 patients with locally-advanced gastric adenocarcinoma into two groups of neoadjuvant chemotherapy and surgery (case) versus surgery alone (control). Because of patient dropouts, we analyzed the results for 22 and 29 patients in case and control groups respectively. The study period was March 21, 2011 to March 20, 2014. A non-randomized set of 23 patients were also added to the control group (Multi-center analysis). The analysis was repeated for non-randomized patients (22 case patients versus 52 control patients).

RESULTS

The mean age of patients in case and control groups was 58.3 ± 9.1 and 59.7 ± 8.7 years of age respectively (p > 0.05). Male to female ratio was 15/7 and 41/11 in case and control groups respectively (p > 0.05). In Randomized patients, 19 patients (86.4%) were resectable in case group; while 16 patients (55.2%) were resectable in control group (p < 0.05). Multicenter analysis also revealed resectability in 19 patients (86.4%) and 31 patients (59.6%) of case and control groups respectively (p < 0.05).

CONCLUSION

We conclude that neoadjuvant chemotherapy could increase tumor resectability rate in patients with locally-advanced gastric adenocarcinoma. However, further studies are necessary to confirm the effect of this modality on patients' overall survival.

Psychometric analysis of a Persian version of the European Organization for Research and Treatment of Cancer OG25 Quality of Life Questionnaire in oesophagogastric cancer patients

BACKGROUND

Health-related quality of life (HRQL) is a fundamental outcome in oncology patients and quality of life (QOL) assessment requires clinically relevant questionnaires. The purpose of this study was translation and definition of measurement properties and the clinical validity of Quality of Life Questionnaire (QLQ) -OG25 module in Persian patients with oesophagus, oesophagogastric junction (OGJ) or gastric cancers.

MATERIALS AND METHODS

The translation procedure followed European Organization for Research and Treatment of Cancer (EORTC) guidelines. Both EORTC QLQ-OG25 and a core questionnaire (EORTC QLQ-C30) were administered to patients with oesophagus (150), OG junction (93) and gastric (32) cancer undergoing multi-modal treatments. Convergent and discriminant validity, Cronbach's alpha coefficient and known-groups comparisons were used to examine reliability and validity.

RESULTS

In all, 275 patients (mean age 62 years) completed both questionnaires. Compliance rate was high and the questionnaire module was well accepted. We found good reliability for multi-item subscales of QLQ-OG25 (Cronbach's alpha coefficients 0.76-0.89). About 73% had TNM staging and scales distinguished between clinically distinct groups of patients. However, patients in palliative group experienced compromised functional status and worse treatment-associated symptoms than those in the potentially curative group. Test-retest scores were consistent. Multi-trait scaling analysis demonstrated good convergent and discriminant validity.

CONCLUSIONS

Overall, the Persian version of QLQ-OG25 demonstrated psychometric and clinical validity that supports its application as a supplement to the original tool (EORTC QLQ-C30) when assessing HRQL in patients with upper-gastrointestinal (GI) cancer both in curative and palliative phases.

Prospective comparison of 3T MRI with diffusion-weighted imaging and MDCT for the preoperative TNM staging of gastric cancer

PURPOSE

To compare the diagnostic performance of 3T magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) and multidetector-row computed tomography (MDCT) for the preoperative TNM staging of gastric cancer.

MATERIALS AND METHODS

This prospective study was approved by our Institutional Review Board. Forty-nine consecutive patients with histologically confirmed gastric cancers underwent MDCT and 3T MRI followed by surgery. MRI without DWI, MRI with DWI, and MDCT were reviewed to determine preoperative TNM staging. Using the pathologic stages as the reference standard, the diagnostic performance of each imaging modality was compared.

RESULTS

Diagnostic accuracies of MRI with DWI, MRI without DWI, and MDCT did not show a significant difference (≤T2 vs. ≥T3: 85.1%, 78.7%, and 80.9%; ≤T3 vs. T4: 76.6%, 74.5%, and 72.3%; N-negative vs. N-positive: 76.6%, 66.0%, and 63.8%; M0 vs. M1: all 95.9%, respectively) (P > 0.05). For N staging, MRI with DWI demonstrated higher sensitivity but lower specificity (86.7% and 58.8%, respectively) than MRI without DWI (50.0% and 94.1%) or MDCT (43.3% and 100%) (P < 0.05).

CONCLUSION

The diagnostic accuracy of 3T MRI is comparable to that of MDCT for the preoperative TNM staging of gastric cancer, and for assessing LN metastasis, the addition of DWI to conventional MRI may increase the sensitivity.

Incidence of microscopically positive proximal margins in adenocarcinoma of the gastroesophageal junction

Aim

To investigate the incidence and risk factors of microscopically positive proximal margins in Chinese patients with adenocarcinoma of the gastroesophageal junction.

Methods

The medical records of 483 patients, who underwent surgical treatment with curative intent for adenocarcinoma of the gastroesophageal junction in a single high-volume tertiary medical center, were reviewed. Demographic, radiographic, endoscopic, pathologic, and treatment-related variables were evaluated. All proximal margins were re-evaluated by two experienced pathologists, and a positive proximal margin was defined as the microscopic presence of invasive tumor cells seen at the esophageal transaction margin submitted en face on final paraffin sections.

Results

The incidence of positive proximal margins was 23.81% in this series. Siewert type, depth of tumor invasion, lymph node involvement, presence of vascular or lymphatic invasion, and presence of perineural invasion were significantly associated with positive proximal margins. On multivariate analysis, the presence of vascular or lymphatic invasion and advanced-stage disease were independent risk factors for positive proximal margins in patients with adenocarcinoma of the gastroesophageal junction.

Conclusion

Residual cancer at proximal resection margins remains a major issue for the surgical treatment of adenocarcinoma of the gastroesophageal junction in China.