Forty six studies were included (n=5,105 patients of whom 4,543 had GIST). One study was prospective and all others were retrospective. Some 63% of studies included more than 30 patients, 91% clearly indicated the tumour site, 43% calculated the diagnostic yield of the various procedures, 28% included a comparison of diagnostic tools, 93% enrolled consecutive patients and 83% provided a clear definition of the disease's molecular diagnosis.
There was considerable variation across studies in the proportion of patients with GIST who presented each of the clinical symptoms examined. Gastrointestinal bleeding was the most common clinical presentation (pooled prevalence 33%, range 0 to 84% across studies).
The pooled diagnostic yield of endoscopy plus mucosal biopsy was 33.8% (range 0 to 100%, based on 11 studies) and of intestinal contrast radiography was 35.1% (range 11 to 100%, based on five studies). The yield of ultrasound endoscopy was 68.7% (range 40 to 100%, based on six studies), which increased to 84% (74 to 100%, based on five studies) when associated with fine needle aspiration biopsy. The diagnostic yield of CT was 73.6% (range 35 to 100%, based on 10 studies) and that of MRI was 91.7% (range 75 to 100%, based on five studies).