No significant association between PIK3CA mutation and survival of esophageal squamous cell carcinoma: A meta-analysis.

The prognostic value of phosphatidylinositol-4, 5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) in patients with esophageal squamous cell carcinoma (ESCC) is controversial. We aimed to investigate the prognostic significance of PIK3CA mutation in patients with ESCC. EMBASE, PubMed, and Web of Science databases were systematically searched from inception through Oct. 3, 2016. The hazard ratios (HRs) and 95% confidence intervals (CI) were calculated using a random effects model for overall survival (OS) and disease-free survival (DFS). Seven studies enrolling 1505 patients were eligible for inclusion of the current meta-analysis. Results revealed that PIK3CA mutation was not significantly associated with OS (HR: 0.90, 95% CI: 0.63-1.30, P=0.591), with a significant heterogeneity (I 2=65.7%, P=0.012). Additionally, subgroup analyses were further conducted according to various variables, such as types of specimen, the sample size, technique and statistical methodology. All results suggested that no significant relationship was found between PIK3CA mutation and OS in patients with ESCC. For DFS, there was no significant association between PIK3CA mutation and DFS in patients with ESCC (HR: 1.00, 95% CI=0.47-2.11, P=0.993, I 2=73.7%). Publication bias was not present and the results of sensitivity analysis were very stable in the current meta-analysis. Our findings suggest that PIK3CA mutation has no significant effects on OS and DFS in ESCC patients. More well-designed prospective studies with better methodology for PIK3CA assessment are required to clarify the prognostic significance of PIK3CA mutation in ESCC patients.

No Significant Association between PIK3CA Mutation and Survival of Esophageal Squamous Cell Carcinoma: A Meta-analysis / 华中科技大学学报（医学）（英德文版）

The prognostic value of phosphatidylinositol-4,5-bisphosphate 3-kinase,catalytic subunit alpha (PIK3CA) in patients with esophageal squamous cell carcinoma (ESCC) is controversial.We aimed to investigate the prognostic significance of PIK3CA mutation in patients with ESCC.EMBASE,PubMed,and Web of Science databases were systematically searched from inception through Oct.3,2016.The hazard ratios (HRs) and 95％ confidence intervals (CI) were calculated using a random effects model for overall survival (OS) and disease-free survival (DFS).Seven studies enrolling 1505 patients were eligible for inclusion of the current meta-analysis.Results revealed that PIK3CA mutation was not significantly associated with OS (HR:0.90,95％ CI:0.63-1.30,P=0.591),with a significant heterogeneity (I2=65.7％,P=0.012).Additionally,subgroup analyses were further conducted according to various variables,such as types of specimen,the sample size,technique and statistical methodology.All results suggested that no significant relationship was found between PIK3CA mutation and OS in patients with ESCC.For DFS,there was no significant association between PIK3CA mutation and DFS in patients with ESCC (HR:1.00,95％ CI=0.47-2.11,P=0.993,I2=73.7％).Publication bias was not present and the results of sensitivity analysis were very stable in the current meta-analysis.Our findings suggest that PIK3CA mutation has no significant effects on OS and DFS in ESCC patients.More well-designed prospective studies with better methodology for PIK3CA assessment are required to clarify the prognostic significance of PIK3CA mutation in ESCC patients.

[Spatiotemporal variations of natural wetland CH4 emissions over China under future climate change].

Based on a new process-based model, TRIPLEX-GHG, this paper analyzed the spatio-temporal variations of natural wetland CH4 emissions over China under different future climate change scenarios. When natural wetland distributions were fixed, the amount of CH4 emissions from natural wetland ecosystem over China would increase by 32.0%, 55.3% and 90.8% by the end of 21st century under three representative concentration pathways (RCPs) scenarios, RCP2. 6, RCP4.5 and RCP8.5, respectively, compared with the current level. Southern China would have higher CH4 emissions compared to that from central and northern China. Besides, there would be relatively low emission fluxes in western China while relatively high emission fluxes in eastern China. Spatially, the areas with relatively high CH4 emission fluxes would be concentrated in the middle-lower reaches of the Yangtze River, the Northeast and the coasts of the Pearl River. In the future, most natural wetlands would emit more CH4 for RCP4.5 and RCP8.5 than that of 2005. However, under RCP2.6 scenario, the increasing trend would be curbed and CH4 emissions (especially from the Qinghai-Tibet Plateau) begin to decrease in the late 21st century.

[Spatiotemporal variation of vegetation in northern Shaanxi of Northwest China based on SPOT-VGT NDVI].

By using 1998-2010 SPOT-VGT NDVI images, this paper analyzed the spatiotemporal variation of vegetation in northern Shaanxi. In 1998-2010, the NDVI in northern Shaanxi had an obvious seasonal variation. The average monthly NDVI was the minimum (0.14) in January and the maximum (0.46) in August, with a mean value of 0.28. The average annual NDVI presented an overall increasing trend, indicating that the vegetation in this area was in restoring. Spatially, the restoration of vegetation in this area was concentrated in central south part, and the degradation mainly occurred in the north of the Great Wall. Air temperature and precipitation were the important climate factors affecting the variation of vegetation, with the linear correlation coefficients to NDVI being 0.72 and 0.58, respectively. The regions with better restored vegetation were mainly on the slopes of 15 degrees-25 degrees, indicating that the Program of Conversion of Cropland to Forestland and Grassland had a favorable effect in the vegetation restoration in northern Shaanxi.