Long-term outcome after surgical resection of non-high-risk gastrointestinal stromal tumours without adjuvant therapy

Background Gastrointestinal stromal tumour (GIST) is the most common intra-abdominal sarcoma. Risk classification systems, commonly the modified National Institutes of Health consensus criteria, identify tumour properties relating to patient outcomes. However, owing to limited long-term evidence, most guidelines recommend up to 10-year follow-up for all risk groups except very low-risk GIST.Methods This retrospective multicentre study included patients who had complete resection of primary, non-metastatic GIST from three Scandinavian sarcoma centres: Gothenburg (2004-2020), Stockholm (2000-2019), and Oslo (2000-2017). Medical records were reviewed for clinical details regarding diagnosis, treatment, and follow-up, and recurrence-free and disease-specific survival evaluated.Results The total cohort consisted of 1213 patients with GIST. High-risk patients and those treated with tyrosine kinase inhibitors were excluded. The remaining 649 patients were included in the present analysis: 118 with very low-, 381 with low-, and 150 with intermediate-risk GISTs. Five-year recurrence-free survival rates were 100, 98.5, and 100 per cent for the intermediate-, low-, and very low-risk groups respectively (P = 0.246). Disease-specific survival rates 10 years after surgery were 100, 98.4, and 100 per cent for the intermediate-, low-, and very low-risk groups respectively (P = 0.262).Conclusion Patients with completely resected non-high-risk GISTs have an excellent long-term outcome, irrespective of risk group. Follow-up programmes to detect disease recurrences in these patients are probably not indicated. Gastrointestinal stromal tumour is the most common intra-abdominal sarcoma, with a variable risk of recurrence. This study showed that that the 5-year recurrence-free survival rate was 99.1 per cent, and the 10-year disease-specific survival rate was 99 per cent for patients in non-high-risk groups in three Scandinavian tertiary care centres with long-term follow-up. The authors therefore suggest that postoperative surveillance might not be needed for these risk groups. Gastrointestinal stromal tumours (GISTs) originate from the muscle layer of the gastrointestinal tract. They are divided into risk groups according to size, location, and how quickly they grow. Patients with GIST, regardless of risk group, have been followed with imaging for several years after their tumour has been successfully removed with an operation. The aim of this study was to evaluate whether follow-up is necessary for patients in the lower-risk groups. Six hundred and forty-nine patients with GISTs from the lower-risk groups were followed for 5 years (median). Only 1.2 per cent of the patients experienced a recurrence of their cancer. It was concluded that patients with GIST in the lower-risk groups do not need follow-up with imaging after a successful operation.