Diagnostic performance of magnifying narrow-band imaging for early gastric cancer: A meta-analysis

AIM: To investigate the performance of magnifying endoscopy with narrow-band imaging(ME-NBI) in the diagnosis of early gastric cancer(EGC).METHODS: Systematic literature searches were conducted until February 2014 in Pub Med, EMBASE, Web of Science, Ovid, Scopus and the Cochrane Library databases by two independent reviewers. Meta-analysis was performed to calculate the pooled sensitivity, specificity and diagnostic odds ratio and to construct a summary receiver operating characteristic(ROC) curve. Subgroup analyses were performed based on the morphology type of lesions, diagnostic standard, the size of lesions, type of assessment, country and sample size to explore possible sources of heterogeneity. A Deeks' asymmetry test was used to evaluate the publication bias.RESULTS: Fourteen studies enrolling 2171 patients were included. The pooled sensitivity, specificity and diagnostic odds ratio for ME-NBI diagnosis of EGC were 0.86(95%CI: 0.83-0.89), 0.96(95%CI: 0.95-0.97) and 102.75(95%CI: 48.14-219.32), respectively, with the area under ROC curve being 0.9623. Among the 14 studies, six also evaluated the diagnostic value of conventional white-light imaging, with a sensitivityof 0.57(95%CI: 0.50-0.64) and a specificity of 0.79(95%CI: 0.76-0.81). When using "VS"(vessel plus surface) ME-NBI diagnostic systems in gastric lesions of depressed macroscopic type, the pooled sensitivity and specificity were 0.64(95%CI: 0.52-0.75) and 0.96(95%CI: 0.95-0.98). For the lesions with a diameter less than 10 mm, the sensitivity and specificity were 0.74(95%CI: 0.65-0.82) and 0.98(95%CI: 0.97-0.98).CONCLUSION: ME-NBI is a promising endoscopic tool in the diagnosis of early gastric cancer and might be helpful in further target biopsy.

Stem cells in gastric cancer

Gastric cancer(GC) is one of the leading causes of cancerrelated mortality worldwide.Cancer stem cells(CSCs),which were first identified in acute myeloid leukemia and subsequently in a large array of solid tumors,play important roles in cancer initiation,dissemination and recurrence.CSCs are often transformed tissue-specific stem cells or de-differentiated transit amplifying progenitor cells.Several populations of multipotent gastric stem cells(GSCs) that reside in the stomach have been determined to regulate physiological tissue renewal and injury repair.These populations include the Villin+ and Lgr5+ GSCs in the antrum,the Troy+ chief cells in the corpus,and the Sox2+ GSCs that are found in both the antrum and the corpus.The disruption of tumor suppressors in Villin+ or Lgr5+ GSCs leads to GC in mouse models.In addition to residing GSCs,bone marrow-derived cells can initiate GC in a mouse model of chronic Helicobacter infection.Furthermore,expression of the cell surface markers CD133 or CD44 defines gastric CSCs in mouse models and in human primary GC tissues and cell lines.Targeted elimination of CSCs effectively reduces tumor size and grade in mouse models.In summary,the recent identification of normal GSCs and gastric CSCs has greatly improved our understanding of the molecular and cellular etiology of GC and will aid in the development of effective therapies to treat patients.

Use of subsequent PET/CT in diffuse large B-cell lymphoma patients in complete remission following primary therapy

Interim 18F-fluorodeoxyglucose(FDG) positron emission tomography/computed tomography(I-PET/CT) is a powerful tool for monitoring the response to therapy in diffuse large B-cell lymphoma(DLBCL). This retrospective study aimed to determine when and how to use I-PET/CT in DLBCL. A total of 197 patients treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone(R-CHOP) were enrolled between October 2005 and July 2011; PET/CT was performed at the time of diagnosis(PET/CT0), after 2 and 4 cycles of chemotherapy(PET/CT2 and PET/CT4, respectively), and at the end of treatment(F-PET/CT). According to the International Harmonization Project for Response Criteria in Lymphoma, 110 patients had negative PET/CT2 scans, and 87 had positive PET/CT2 scans. The PET/CT2-negative patients had significantly higher 3-year progression-free survival rate(75.8% vs. 38.2%) and 3-year overall survival rate(93.5% vs. 55.6%) than PET/CT2-positive patients. All PET/CT2-negative patients remained negative at PET/CT4, but 3 were positive at F-PET/CT. Among the 87 PET/CT2-positive patients, 57 remained positive at F-PET/CT, and 32 progressed during chemotherapy(15 at PET/CT4 and 17 at F-PET/CT). Comparing PET/CT4 with PET/CT0, 7 patients exhibited progression, and 8 achieved partial remission. Comparing F-PET/CT with PET/CT0, 10 patients exhibited progression, and 7 achieved partial remission. In conclusion, our results indicate that I-PET/CT should be performed after 2 rather than 4 cycles of immunochemotherapy in DLBCL patients. There is a limited role for subsequent PET/CT in the detection of relapse in PET/CT2-negative patients, but repeat PET/CT is required if the PET/CT2 findings are positive.

Qualitative visual trichotomous assessment improves the value of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in predicting the prognosis of diffuse large B-cell lymphoma

Introduction:Fluorine-18 fluorodeoxyglucose(18F-FDG)positron emission tomography/computed tomography(PET/CT)is a powerful tool for monitoring the response of diffuse large B-cell lymphoma(DLBCL)to therapy,but the criteria to interpret PET/CT results remain under debate.We investigated the value of post-treatment PET/CT in predicting the prognosis of DLBCL patients when interpreted according to qualitative visual trichotomous assessment(QVTA)criteria compared with the Deauvil e criteria.Methods:In this retrospective study,final PET/CT scans of DLBCL patients treated with rituximab-based regimens between October 2005 and November 2010 were interpreted using the Deauvil e and QVTA criteria.Survival curves were estimated using Kaplan-Meier analysis and compared using the log-rank test.Results:A total of 253 patients were enrol ed.The interpretation according to the Deauvil e criteria revealed that 181patients had negative PET/CT scan results and 72 had positive results.The 3 year overal survival(OS)rate was significantly higher in patients with negative scan results than in those with positive results(91.6%vs.57.5%,P<0.001).The72 patients with positive scan results according to the Deauville criteria were divided into two groups by the interpretation according to the QVTA criteria:29 had indeterminate results,and 43 had positive results.The 3 year OS rate was significantly higher in patients with indeterminate scan results than in those with positive results(91.2%vs.33.5%,P<0.001)but was similar between patients with negative and indeterminate scan results(91.6%vs.91.2%,P=0.921).Conclusions:Compared with the Deauvil e criteria,using the QVTA criteria for interpreting post-treatment PET/CT scans of DLBCL patients is likely to reduce the number of false positive results.The QVTA criteria are feasible for therapeutic outcome evaluation and can be used to guide risk-adapted therapy.

Characteristics of vapor based on complex networks in China

The uneven spatial distribution of stations providing precipitable water vapor(PWV)observations in China hinders the effective use of these data in assimilation,nowcasting,and prediction.In this study,we proposed a complex network framework for exploring the topological structure and the collective behavior of PWV in the mainland of China.We used the Pearson correlation coefficient and transfer entropy to measure the linear and nonlinear relationships of PWV amongst different stations and to set up the undirected and directed complex networks,respectively.Our findings revealed the statistical and geographical distribution of the variables influencing PWV networks and identified the vapor information source and sink stations.Specifically,the findings showed that the statistical and spatial distributions of the undirected and directed complex vapor networks in terms of degree and distance were similar to each other(the common interaction mode for vapor stations and their locations).The betweenness results displayed different features.The largest betweenness ratio for directed networks tended to be larger than that of the undirected networks,implying that the transfer of directed PWV networks was more efficient than that of the undirected networks.The findings of this study are heuristic and will be useful for constructing the best strategy for the PWV data in applications such as vapor observational networks design and precipitation prediction.

A Marked Increase in Obstetric Hysterectomy for Placenta Accreta

Background：Obstetric hysterectomy （OH） as a lifesaving measure to manage uncontrolled uterine hemorrhage appears to be increasing recently.The objective of this study was to determine the etiology and changing trends of OH and to identify those at particular risk of OH to enhance the early involvement of multidisciplinary intensive care.Methods：A retrospective study was carried out in patients who had OH in China-Japan Friendship Hospital from 2004 to 2014.Maternal characteristics,preoperative evaluation,operative reports,and prenatal outcomes were studied in detail.Results：There were 19 cases of OH among a total of 18,838 deliveries.Comparing the study periods between 2004-2010 and 2011-2014,OH increased from 0.8/1000 （10/12,890） to 1.5/1000 （9/5948）.Indications for OH have changed significantly during this study period with uterine atony decreasing from 50.0% （5/10） to 11.1% （1/9） （P 〈 0.05）,and placenta accreta as the indication for OH has increased significantly from 20.0% （2/10） to 77.8% （7/9） （P 〈 0.05）.Ultrasonography and magnetic resonance imaging （MRI） have been used to make an exact antepartum diagnosis of placenta accreta.A multidisciplinary management led to improved outcomes for patients with placenta accreta.Conclusion：As the multiple cesarean delivery rates have risen,there has been a dramatic increase in OH for placenta accreta.An advance antenatal diagnosis of ultrasonography,and MRI,and a multidisciplinary teamwork can maximize patients＇ safety and outcome.