Evidence mapping based on systematic reviews of therapeutic interventions for soft tissue sarcomas

Soft tissue sarcomas are a heterogeneous group of rare tumours of mesenchymal origin. Evidence mapping is one of the most didactic and friendly approaches to organise and summarise the range of research activity in broad topic fields. The objective of this evidence mapping is to identify, describe and organise the current available evidence about therapeutic interventions on soft tissues sarcomas. We followed the methodology of global evidence mapping. We performed a search of the PubMed, EMBASE, The Cochrane Library and Epistemonikos to identify systematic reviews (SRs) with or without meta-analyses published between 1990 and March 2016. Two independent literature reviewers assessed eligibility and extracted data. Methodological quality of the included systematic reviews was assessed using AMSTAR. We organised the results according to identified PICO questions and used tables and a bubble plot to display the results. The map is based on 24 SRs that met eligibility criteria and included 66 individual studies. Three-quarters were either observational or uncontrolled clinical trials. The quality of the included SRs was in general moderate or high. We identified 64 PICO questions from them. The corresponding results mostly favoured the intervention arm. This evidence mapping was built on the basis of SRs, which mostly included non-experimental studies and were qualified by the AMSTAR tool as of moderate quality. The evidence mapping created from PICO questions is a useful approach to describe complex and huge clinical topics through graphical media and orientate further research to fulfil the existing gaps. However, it is important to delimitate the steps of the evidence mapping in a pre-established protocol.