Determinants of the access to remote specialised services provided by national sarcoma reference centres

BACKGROUND: Spatial inequalities in cancer management have been evidenced by studies reporting lower quality of care or/and lower survival for patients living in remote or socially deprived areas. NETSARC+ is a national reference network implemented to improve the outcome of sarcoma patients in France since 2010, providing remote access to specialized diagnosis and Multidisciplinary Tumour Board (MTB). The IGéAS research program aims to assess the potential of this innovative organization, with remote management of cancers including rare tumours, to go through geographical barriers usually impeding the optimal management of cancer patients. METHODS: Using the nationwide NETSARC+ databases, the individual, clinical and geographical determinants of the access to sarcoma-specialized diagnosis and MTB were analysed. The IGéAS cohort (n = 20,590) includes all patients living in France with first sarcoma diagnosis between 2011 and 2014. Early access was defined as specialised review performed before 30 days of sampling and as first sarcoma MTB discussion performed before the first surgery. RESULTS: Some clinical populations are at highest risk of initial management without access to sarcoma specialized services, such as patients with non-GIST visceral sarcoma for diagnosis [OR 1.96, 95% CI 1.78 to 2.15] and MTB discussion [OR 3.56, 95% CI 3.16 to 4.01]. Social deprivation of the municipality is not associated with early access on NETSARC+ remote services. The quintile of patients furthest away from reference centres have lower chances of early access to specialized diagnosis [OR 1.18, 95% CI 1.06 to 1.31] and MTB discussion [OR 1.24, 95% CI 1.10 to 1.40] but this influence of the distance is slight in comparison with clinical factors and previous studies on the access to cancer-specialized facilities. CONCLUSIONS: In the context of national organization driven by reference network, distance to reference centres slightly alters the early access to sarcoma specialized services and social deprivation has no impact on it. The reference networks' organization, designed to improve the access to specialized services and the quality of cancer management, can be considered as an interesting device to reduce social and spatial inequalities in cancer management. The potential of this organization must be confirmed by further studies, including survival analysis

Pantropical variability in tree crown allometry

Aim Tree crowns determine light interception, carbon and water exchange. Thus, understanding the factors causing tree crown allometry to vary at the tree and stand level matters greatly for the development of future vegetation modelling and for the calibration of remote sensing products. Nevertheless, we know little about large‐scale variation and determinants in tropical tree crown allometry. In this study, we explored the continental variation in scaling exponents of site‐specific crown allometry and assessed their relationships with environmental and stand‐level variables in the tropics. Location Global tropics. Time period Early 21st century. Major taxa studied Woody plants. Methods Using a dataset of 87,737 trees distributed among 245 forest and savanna sites across the tropics, we fitted site‐specific allometric relationships between crown dimensions (crown depth, diameter and volume) and stem diameter using power‐law models. Stand‐level and environmental drivers of crown allometric relationships were assessed at pantropical and continental scales. Results The scaling exponents of allometric relationships between stem diameter and crown dimensions were higher in savannas than in forests. We identified that continental crown models were better than pantropical crown models and that continental differences in crown allometric relationships were driven by both stand‐level (wood density) and environmental (precipitation, cation exchange capacity and soil texture) variables for both tropical biomes. For a given diameter, forest trees from Asia and savanna trees from Australia had smaller crown dimensions than trees in Africa and America, with crown volumes for some Asian forest trees being smaller than those of trees in African forests. Main conclusions Our results provide new insight into geographical variability, with large continental differences in tropical tree crown allometry that were driven by stand‐level and environmental variables. They have implications for the assessment of ecosystem function and for the monitoring of woody biomass by remote sensing techniques in the global tropics

Interactions between fire and climate in the Western Ghats, India

International audienc

Interactions between fire and climate in the Western Ghats, India

International audienc