Wei-Ming Kang

Treatment strategy for early gastric cancer

Gastric cancer ranks the second leading cause of cancer-specific mortality worldwide. With a poor prognosis, 5-year survival rate of gastric cancer is less than 20%-25% in the USA, Europe, and China [1]. However, early gastric cancer(EGC) offers an excellent (over 90%) chance of cure based on surgical resection [2]. As the increasing detection of EGC, more treatment options have been developed both curatively and minimally invasively to maintain a good quality of life(QOL). One of the advanced therapeutic techniques is endoscopic dissection. Improvements in surgical treatment include minimizing lymph node dissection, reconstruction methods, laparoscopy-assisted surgery, and sentinel node navigation surgery(SNNS) [3]. With technological advances, even Natural Orifice Transluminal Endoscopy Surgery (NOTES) and robotic surgery are expected to represent the next revolution [4]. However, there still remains much dispute among these treatments, which arouses further clinical trials to verify. Update of the treatments, controversial indications, prognosis and current strategies for EGC are discussed in this review.

Superiority of a fish oil–enriched emulsion to medium-chain triacylglycerols/long-chain triacylglycerols in gastrointestinal surgery patients: A randomized clinical trial

OBJECTIVE Compared with soybean oil, a fish oil-enriched emulsion can improve the clinical outcomes of patients requiring parenteral nutrition. However, the superiority of fish oil emulsion to medium-chain triacylglycerols/long-chain triacylglycerols for short-term administration has seldom been discussed. METHODS Sixty-four adult patients with gastrointestinal diseases were randomly assigned to receive isocaloric and isonitrogenous total parenteral nutrition with an ω-3 fatty acid-enriched emulsion (Lipoplus; study group, n = 32) or medium-chain triacylglycerols/long-chain triacylglycerols (Lipofundin; control group, n = 32) for 5 d after surgery. Safety and efficacy parameters were assessed on postoperative days 1, 3, and 6. RESULTS Clinical outcomes including infectious complications and systemic inflammatory response syndrome were comparable between the two groups. Total bilirubin decreased over time in the study group versus an increase in the control group (P = 0.017). Activated partial thromboplastin time in the study group was prolonged significantly compared with the control group from days 1 to 3 (P = 0.002), although the prolongation stopped at the study termination. There were no differences in changes of C-reactive protein, interleukin (IL)-1, IL-8, IL-10, vascular endothelial growth factor (VEGF), and the distribution of the T-cell subpopulation between the two groups. However, fish oil consumption led to an increase in leukotriene B5/ leukotriene B4 and significant decreases in IL-6, tumor necrosis factor-α, and nuclear factor-κB. Furthermore, the overall changes in tumor necrosis factor-α and nuclear factor-κB were positively associated (R(2) = 0.295, P < 0.001). CONCLUSIONS Gastrointestinal surgery patients benefited from a fish oil-enriched emulsion rather than medium-chain triacylglycerols/long-chain triacylglycerols in the amelioration of liver function and immune status. The positive association of tumor necrosis factor-α and nuclear factor-κB might be involved in the potential anti-inflammation mechanism of fish oil.

Significance of Serum Pepsinogens as a Biomarker for Gastric Cancer and Atrophic Gastritis Screening: A Systematic Review and Meta-Analysis

Background Human pepsinogens are considered promising serological biomarkers for the screening of atrophic gastritis (AG) and gastric cancer (GC). However, there has been controversy in the literature with respect to the validity of serum pepsinogen (SPG) for the detection of GC and AG. Consequently, we conducted a systematic review and meta-analysis to assess the diagnostic accuracy of SPG in GC and AG detection. Methods We searched PubMed, Embase, and the Chinese National Knowledge Infrastructure (CNKI) for correlative original studies published up to September 30, 2014. The summary sensitivity, specificity, positive diagnostic likelihood ratio (DLR+), negative diagnostic likelihood ratio (DLR-), area under the summary receiver operating characteristic curve (AUC) and diagnostic odds ratio (DOR) were used to evaluate SPG in GC and AG screening based on bivariate random effects models. The inter-study heterogeneity was evaluated by the I2 statistics and publication bias was assessed using Begg and Mazumdar’s test. Meta-regression and subgroup analyses were performed to explore study heterogeneity. Results In total, 31 studies involving 1,520 GC patients and 2,265 AG patients were included in the meta-analysis. The summary sensitivity, specificity, DLR+, DLR-, AUC and DOR for GC screening using SPG were 0.69 (95% CI: 0.60–0.76), 0.73 (95% CI: 0.62–0.82), 2.57 (95% CI: 1.82–3.62), and 0.43 (95% CI: 0.34–0.54), 0.76 (95% CI: 0.72–0.80) and 6.01 (95% CI: 3.69–9.79), respectively. For AG screening, the summary sensitivity, specificity, DLR+, DLR-, AUC and DOR were 0.69 (95% CI: 0.55–0.80), 0.88 (95% CI: 0.77–0.94), 5.80 (95% CI: 3.06–10.99), and 0.35 (95% CI: 0.24–0.51), 0.85 (95% CI: 0.82–0.88) and 16.50 (95% CI: 8.18–33.28), respectively. In subgroup analysis, the use of combination of concentration of PGI and the ratio of PGI:PGII as measurement of SPG for GC screening yielded sensitivity of 0.70 (95% CI: 0.66–0.75), specificity of 0.79 (95% CI: 0.79–0.80), DOR of 6.92 (95% CI: 4.36–11.00), and AUC of 0.78 (95% CI: 0.72–0.81), while the use of concentration of PGI yielded sensitivity of 0.55 (95% CI: 0.51–0.60), specificity of 0.79 (95% CI: 0.76–0.82), DOR of 6.88 (95% CI: 2.30–20.60), and AUC of 0.77 (95% CI: 0.73–0.92). For AG screening, the use of ratio of PGI:PGII as measurement of SPG yielded sensitivity of 0.69 (95% CI: 0.52–0.83), specificity of 0.84 (95% CI: 0.68–0.93), DOR of 11.51 (95% CI: 6.14–21.56), and AUC of 0.83 (95% CI: 0.80–0.86), the use of combination of concentration of PGI and the ratio of PGI:PGII yield sensitivity of 0.79 (95% CI: 0.72–0.85), specificity of 0.89 (95% CI: 0.85–0.93), DOR of 24.64 (95% CI: 6.95–87.37), and AUC of 0.87 (95% CI: 0.81–0.92), concurrently, the use of concentration of PGI yield sensitivity of 0.46 (95% CI: 0.38–0.54), specificity of 0.93 (95% CI: 0.91–0.95), DOR of 19.86 (95% CI: 0.86–456.91), and AUC of 0.86 (95% CI: 0.52–1.00). Conclusion SPG has great potential as a noninvasive, population-based screening tool in GC and AG screening. In addition, given the potential publication bias and high heterogeneity of the included studies, further high quality studies are required in the future.

Laparoscopic-endoscopic cooperative surgery for gastric submucosal tumors.

AIM To assess the feasibility, safety, and advantages of minimally invasive laparoscopic-endoscopic cooperative surgery (LECS) for gastric submucosal tumors (SMT). METHODS We retrospectively analyzed 101 consecutive patients, who had undergone partial, proximal, or distal gastrectomy using LECS for gastric SMT at Peking Union Medical College Hospital from June 2006 to April 2013. All patients were followed up by visit or telephone. Clinical data, surgical approach, pathological features such as the size, location, and pathological type of each tumor; and follow-up results were analyzed. The feasibility, safety and effectiveness of LECS for gastric SMT were evaluated, especially for patients with tumors located near the cardia or pylorus. RESULTS The 101 patients included 43 (42.6%) men and 58 (57.4%) women, with mean age of 51.2 ± 13.1 years (range, 14-76 years). The most common symptom was belching. Almost all (n = 97) patients underwent surgery with preservation of the cardia and pylorus, with the other four patients undergoing proximal or distal gastrectomy. The mean distance from the lesion to the cardia or pylorus was 3.4 ± 1.3 cm, and the minimum distance from the tumor edge to the cardia was 1.5 cm. Tumor pathology included gastrointestinal stromal tumor in 78 patients, leiomyoma in 13, carcinoid tumors in three, ectopic pancreas in three, lipoma in two, glomus tumor in one, and inflammatory pseudotumor in one. Tumor size ranged from 1 to 8.2 cm, with 65 (64.4%) lesions < 2 cm, 32 (31.7%) > 2 cm, and four > 5 cm. Sixty-six lesions (65.3%) were located in the fundus, 21 (20.8%) in the body, 10 (9.9%) in the antrum, three (3.0%) in the cardia, and one (1.0%) in the pylorus. During a median follow-up of 28 mo (range, 1-69 mo), none of these patients experienced recurrence or metastasis. The three patients who underwent proximal gastrectomy experienced symptoms of regurgitation and belching. CONCLUSION Laparoscopic-endoscopic cooperative surgery is feasible and safe for patients with gastric submucosal tumor. Endoscopic intraoperative localization and support can help preserve the cardia and pylorus during surgery.

Combined Detection of CEA, CA 19-9, CA 242 and CA 50 in the Diagnosis and Prognosis of Resectable Gastric Cancer

Our aim was to investigate the value of combined detection of serum carcinoembryonic antigen (CEA), carbohydrate antigen (CA) 19-9, CA 242 and CA 50 in diagnosis and assessment of prognosis in consecutive gastric cancer patients. Clinical data including preoperative serum CEA, CA 19-9, CA 242, and CA 50 values and information on clinical pathological factors were collected and analyzed retrospectively. Univariate and multivariate survival analyses were used to explore the relationship between tumor markers and survival. Positive rates of tumor markers CEA, CA 19-9, CA 242 and CA 50 in the diagnosis of gastric cancer were 17.7, 17.1, 20.4 and 13.8%, respectively, and the positive rate for all four markers combined was 36.6%. Patients with elevated preoperative serum concentrations of CEA, CA 19-9, CA 242 and CA 50, had late clinical tumor stage and significantly poorer overall survival. Five-year survival rates in patients with elevated CEA, CA 19-9, CA 242 and CA 50 were 28.1, 25.8, 27.0 and 24.1%, respectively, compared with 55.0, 55.4, 56.4 and 54.5% in patients with these markers at normal levels (p<0.01). In multivariate Cox proportional hazards analyses, an elevated CA 242 level was determined to be an independent prognostic marker in gastric cancer patients. Combined detection of four tumor markers increased the positive rate for gastric cancer diagnosis. CA 242 showed higher diagnostic value and CA 50 showed lower diagnostic value. In resectable gastric carcinoma, preoperative CA 242 level was associated with disease stage, and was found to be a significant independent prognostic marker in gastric cancer patients.

Effects of Glutamine Supplementation on Patients Undergoing Abdominal Surgery

OBJECTIVE To evaluate the effects of supplementation of glutamine (GLN) on maintaining glutathione (GSH) level, immune system function, liver function, and clinical outcome of patients receiving abdominal operation. METHODS Forty patients undergoing elective abdominal surgical treatment were randomly divided into 2 groups: study group (n = 20) and control group (n = 20). All patients received total parenteral nutrition (TPN) for up to 7 days during perioperative period. The study group received TPN supplemented with GLN dipeptide while the control group received TPN without GLN dipeptide. Patients in both groups received equivalent nitrogen and caloric intake. Blood sample was taken on preoperative day, and the 1st, 3rd, 6th postoperative day to measure GSH level, immune indexes, and liver function indexes. RESULTS The decrease of GSH level in plasma and red blood cell (RBC) in study group was less than that in control group during postoperative period. Ratio of GSH/glutathione disulfide (GSSG) in plasma in study group was higher than that in control group on the 3rd postoperative day (52.53 +/- 11.46 vs. 31.43 +/- 7.27, P = 0.001). Albumin level in study group was higher than that in control group on the 3rd postoperative day (37.7 +/- 3.8 g/L vs. 33.8 +/- 4.2 g/L, P = 0.02). There was no significant difference in the levels of immunoglobin (IgG, IgM, IgA) or T lymphocyte subgroup (CD4, CD8, CD4/CD8) in both groups during postoperative period. There was one case with infectious complication in control group, while none in study group. A trend of shortened hospital stay was observed in study group compared with control group (22.3 +/- 2.1 d vs. 24.9 +/- 1.7 d, P = 0.32). CONCLUSIONS Supplementation of GLN-enriched TPN has beneficial effects on maintaining GSH levels in plasma and RBC, sustaining GSH/GSSG ratio and albumin level, and keeping antioxidant abilities during postoperative period in patients with abdominal operation, with the trends of decreasing incidence of infectious complication and shortening hospital stay.

Overexpression of eukaryotic translation initiation factor 5A2 (EIF5A2) correlates with cell aggressiveness and poor survival in gastric cancer.

Eukaryotic translation initiation factor 5A2 (EIF5A2) plays an important role in tumor progression and prognosis evaluation. However, little information is available about its potential role in gastric cancer. This study aimed to investigate the function of EIF5A2 in tumor progression and its potential mechanisms. EIF5A2 expression was measured in human gastric cancer cell lines, the immortalized gastric mucosal epithelial cell line (GES-1) and human gastric cancer tissues and knocked down by RNA interference or upregulated by EIF5A2 plasmid transfection. Cell proliferation, migration and invasion were assessed in vitro. The downstream targets of EIF5A2 were examined by western blotting. EIF5A2 and its potential target metastasis-associated protein 1 (MTA1) expression were examined in 160 pairs of human gastric cancer and adjacent non-tumor specimens using immunohistochemistry (IHC) staining, and its correlation with clinicopathological features and survival was investigated. Knockdown of EIF5A2 or MTA1 caused an apparent suppression of HGC27 cell proliferation, migration and invasion. After knockdown of EIF5A2 in HGC27 cells, E-cadherin levels were upregulated and vimentin, cyclin D1, cyclin D3, C-MYC and MTA1 levels were downregulated. Upregulation of EIF5A2 in MKN45 cells resulted in the converse. IHC results showed a positive correlation between EIF5A2 and MTA1 expression in gastric cancers (P<0.001). Both EIF5A2 and MTA1 overexpression were correlated with pT stage (P=0.018 and P=0.042), pN stage (P=0.037 and P=0.020) and lymphovascular invasion (P=0.016 and P=0.044). EIF5A2 or MTA1 overexpression was significantly associated with poor overall survival and disease-free survival (All P<0.05). Multivariate analyses identified EIF5A2 as an independent predictor for both overall survival (P=0.012) and disease-free survival (P=0.008) in gastric cancer patients. Our findings indicate that EIF5A2 upregulation plays an important oncogenic role in gastric cancer. EIF5A2 may represent a new predictor for poor survival and is a potential therapeutic target for gastric cancer.

Cadherin-17 induces tumorigenesis and lymphatic metastasis in gastric cancer through activation of NFκB signaling pathway

Cadherin-17 (CDH17), as a structurally unique member of the cadherin superfamily, has been identified to predict a poor prognosis for gastric cancer (GC). Our previous study demonstrated the positive correlation between CDH17 and lymph node micrometastasis in GC. We sought to further identify the role of CDH17 in the tumorigenesis and lymphatic metastasis of GC. Hence, we inhibited the CDH17 expression in MKN-45 gastric cancer cells by using RNA interference. Consequently, the malignant potency of cancer cells was evaluated, and the change in NFκB signaling pathway was also probed. Tumor growth and lymphatic metastasis model were conducted in nude mice to confirm the hypothesis. Downregulation of CDH17 not only suppressed the proliferation, adherence and invasion potency of MKN-45 cells, but also induced cell cycle arrest. Meanwhile, the NFκB signaling pathway was inactivated as well, with the reductions of downstream proteins including VEGF-C and MMP-9. Moreover, silencing CDH17 inhibited tumor growth in vivo significantly, and there was no lymph node metastasis detected in the mice without CDH17 expression, as opposed to the positive nodes found in controls. CDH17 is a novel oncogene in gastric cancer cells, which is associated with lymphatic metastasis and proliferation strongly. The inactivation of NFκB signaling pathway might be involved in targeting CDH17 in GC. On the whole, CDH17 is proposed to serve as a biomarker and attractive therapeutic target in GC.

miR-935 suppresses gastric signet ring cell carcinoma tumorigenesis by targeting Notch1 expression

Gastric signet ring cell carcinoma (GSRCC) is a unique pathological type of gastric carcinoma that is extremely invasive and has a poor prognosis. Expression of microRNAs (miRNAs) has been closely linked to the carcinogenesis of gastric cancer and has been considered as a powerful prognostic marker. The function of miR-935 has never been reported in cancer before. We found, using microRNA array, that expression of miR-935 in GSRCC cell lines is lower than in non-GSRCC cell lines, and enhanced expression of miR-935 in GSRCC cell-lines inhibit cell proliferation, migration and invasion. We also identified Notch1 as a direct target of miR-935. Knockdown of Notch1 reduced proliferation, migration/invasion of GSRCC cells, and overexpression Notch1s activated form (Notch intracellular domain) could rescue miR-935s tumor suppressive effect on GSRCC. Expression of miR-935 was lower in gastric carcinoma tissue than in paired normal tissue samples, and lower in GSRCC than in non-GSRCC. Our results demonstrate the inverse correlation between the expression of miR-935 and Notch1 in gastric tissues. We conclude that miR-935 inhibits gastric carcinoma cell proliferation, migration and invasion by targeting Notch1, suggesting potential applications of the miR-935-Notch1 pathway in gastric cancer clinical diagnosis and therapeutics, especially in gastric signet ring cell carcinoma.

Negative Association of c-fos Expression as a Favorable Prognostic Indicator in Gastric Cancer

BACKGROUND AND AIMS The onco-protein c-fos was previously linked to favorable prognosis of gastric cancer (GC) without further validations. The present study was designed to address the issue based on a cohort of Chinese patients. METHODS Expression of c-fos was determined by immunohistochemical staining in specimens from 58 patients with GC who underwent surgical resection. The relationships between c-fos expression and clinicopathological and prognostic variables were further evaluated. RESULTS Expression of c-fos in tumor epithelia was observed in 39 (67.2%) patients. The protein was also positively expressed in lymphocytes within tumors and para-tumor epithelia. Tumors with positive expression of c-fos in tumor epithelia had a smaller size and marginally earlier T stage in all patients and/or those who underwent curative resection. Univariate analysis showed that patients with positive c-fos expression in tumor epithelia had significantly prolonged overall and tumor-free survival. Cox regression analysis revealed that c-fos expression in tumor epithelia was an independent or potential independent indicator of improved prognosis in different subgroups of patients. Expression of c-fos in para-tumor epithelia and intra-tumor lymphocytes was not associated with clinicopathological variables and long-term outcomes in patients. CONCLUSIONS Our data demonstrated that c-fos expression was negatively associated with tumor progression and was predictive for favorable survival in patients with GC.