Background: Gastrointestinal Stromal Tumours (GISTs) are the most common mesenchymal tumours. The evidence in this research field is broad and the body of evidence is scattered and expanding.
Objectives: The purpose of this evidence-mapping (EM) project is to identify, describe and organise the current-available evidence about therapeutic interventions on sarcomas.
Methods: We conducted an EM based on the methodology proposed by Global Mapping Initiative. The stages of the process were: (1) Setting the boundaries and context of the evidence map: We consulted the World Health Organization classification and oncology experts; (2) Searching and selection of systematic reviews: We conducted searches in PubMed, EMBASE, the Cochrane Library, and Epistemonikos from 1990 to March 2016; the former was updated in November 2016; (3) Data analysis: We obtained general characteristics from systematic reviews (SRs) and the specific research questions addressed in these documents; and, (4) Synthesising findings: We displayed the information in tables and bubble plots.
Results: This mapping was based on 17 published SRs including 66 individual studies conducted between 2001 and 2014. Of the total studies included, 43 were observational studies, 15 were randomised-controlled trials (RCT), and 8 were phase II clinical trials. According to the clinical spectrum we divided the PICOs into patients with localised GIS and patients with unresectable and/or metastatic GIST.The majority of the interventions reported as 'beneficial' were palliative. Only 3 studies evaluated quality of life as an outcome and none of them conducted an economic evaluation. Overall, the quality of the SRs according to AMSTAR was moderate to high (see the bubble plot).
Conclusions: The most common type of study used to evaluate therapeutic interventions in GIST sarcomas has been non-experimental studies. However, the majority of interventions are reported as beneficial or probably beneficial by the respective authors of SRs. Evidence mapping is a useful and reliable methodology to identify and present existing evidence about therapeutic interventions.