Increasing pancreatic cancer is not paralleled by pancreaticoduodenectomy volumes in Brazil:A time trend analysis

Background: Currently, surgical resection represents the only curative treatment for pancreatic cancer(PC), however, the majority of tumors are no longer resectable by the time of diagnosis. The aim of this study was to describe time trends and distribution of pancreaticoduodenectomies(PDs) performed for treating PC in Brazil in recent years. Methods: Data were retrospectively obtained from Brazilian Health Public System(namely DATASUS) regarding hospitalizations for PC and PD in Brazil from January 2008 to December 2015. PC and PD rates and their mortalities were estimated from DATASUS hospitalizations and analyzed for age, gender and demographic characteristics. Results: A total of 2364 PDs were retrieved. Albeit PC incidence more than doubled, the number of PDs increased only 37%. Most PDs were performed in men(52.2%) and patients between 50 and 69 years old(59.5%). Patients not surgically treated and those 70 years or older had the highest in-hospital mortality rates. The most developed regions(Southeast and South) as well as large metropolitan integrated municipalities registered 76.2% and 54.8% of the procedures, respectively. LMIM PD mortality fluctuated, ranging from 13.6% in 2008 to 11.8% in 2015. Conclusions: This study suggests a trend towards regionalization and volume-outcome relationships for PD due to PC, as large metropolitan integrated municipalities registered most of the PDs and more stable mortality rates. The substantial differences between PD and PC increasing rates reveals a limiting step on the health system resoluteness. Reduction in the number of hospital beds and late access to hospitalization, despite improvement in diagnostic methods, could at least in part explain these findings.

Inter-annual variations in vegetation and their response to climatic factors in the upper catchments of the Yellow River from 2000 to 2010

To understand the variations in vegetation and their correlation with climate factors in the upper catchments of the Yellow River, China, Normalized Difference Vegetation Index（NDVI） time series data from 2000 to 2010 were collected based on the MOD13Q1 product. The coefficient of variation, Theil–Sen median trend analysis and the Mann–Kendall test were combined to investigate the volatility characteristic and trend characteristic of the vegetation. Climate data sets were then used to analyze the correlation between variations in vegetation and climate change. In terms of the temporal variations, the vegetation in this study area improved slightly from 2000 to 2010, although the volatility characteristic was larger in 2000–2005 than in 2006–2010. In terms of the spatial variation, vegetation which is relatively stable and has a significantly increasing trend accounts for the largest part of the study area. Its spatial distribution is highly correlated with altitude, which ranges from about 2000 to 3000 m in this area. Highly fluctuating vegetation and vegetation which showed a significantly decreasing trend were mostly distributed around the reservoirs and in the reaches of the river with hydropower developments. Vegetation with a relatively stable and significantly decreasing trend and vegetation with a highly fluctuating and significantly increasing trend are widely dispersed. With respect to the response of vegetation to climate change, about 20–30% of the vegetation has a significant correlation with climatic factors and the correlations in most areas are positive： regions with precipitation as the key influencing factor account for more than 10% of the area; regions with temperature as the key influencing factor account for less than 10% of the area; and regions with precipitation and temperature as the key influencing factors together account for about 5% of the total area. More than 70% of the vegetation has an insignificant correlation with climatic factors.