A multi-centre analysis of the impact of updated risk stratification on follow-up of gastric gastro-intestinal stromal tumours in the post-imatinib era

Abstract

Background: Previously Gastro-Intestinal Stromal Tumours (GISTs) have been risk stratified histologically according to their size and mitotic index. However, gastric GISTs have a lower likelihood of recurrence and so the Miettinen criteria are now used to risk stratify patients. Records were reviewed from multiple centres to determine if these changes altered patients' clinical care and also to determine the survival of patients following the introduction of imatinib therapy.

Methods: Prospective databases of GISTs undergoing surgical resection and those reviewed by the regional sarcoma MDT were cross-referenced and added to by searching a variety of clinical and pathology coding datasets, to identify patients diagnosed between January 2000 and March 2010. Patients undergoing resection for localised disease were re-scored using Miettinen criteria and Kaplan-Meier analysis was used to determine survival outcomes.

Results: The search identified 203 patients; including 132 gastric GISTs, 89 of which had resections of untreated localised disease. These were reassessed, of which approximately one third were scored as intermediate risk. Following reclassification, 26 of 29 of intermediate risk cases moved to low risk groups, representing 27.7% of all those remaining in follow-up at the time of audit. Median survival was not reached after a median follow-up of 3.85 years and 4-year survival was estimated at 72%.

Conclusions: Clinicians involved in the follow-up of gastric GISTs should reassess the pathology of all intermediate and high risk patients in order to decrease patient exposure to stressful interventions, as well as hospital workload, and expenditure on unnecessary observation.