AIM: To determine the frequency, time course and sites of recurrence following surgical resection of gastrointestinal stromal tumours (GIST) and to evaluate the performance of a risk-based surveillance protocol in detection of recurrence. METHODS: Eighty-one patients on surveillance following complete resection of GIST were included. Patients were stratified into risk groups according to accepted histopathological criteria. Computed tomography (CT) examinations were retrospectively reviewed to determine rates, sites and imaging characteristics of recurrence and to assess compliance with the local follow-up protocol. RESULTS: The median time of follow-up was 41 months. Nineteen patients suffered recurrence, all of whom were in the high-risk group. Fifty-eight percent of relapses occurred within 1 year and 84% within 3 years. Even within the high-risk group, patients with relapse had significantly larger (mean 15 versus 10.4 cm, p < 0.05) and more mitotically active primary tumours (mean 33.7 versus 5.6 mitoses per 50 high-power fields; p < 0.05) than those with no relapse. Relapse was to the liver in 12 cases (63%) and to the omentum and mesentery in nine cases (47%), and was asymptomatic in three-quarters of patients. CONCLUSIONS: The high incidence of GIST recurrence in the high-risk group in the first 3 years after surgery supports the use of intensive imaging surveillance in this period. Relapse is often asymptomatic and commonly occurs to the liver, omentum and mesentery. Stratification by tumour factors may enable improved tailoring of surveillance protocols within the high-risk group in the future.
AIM: To determine the frequency, time course and sites of recurrence following surgical resection of gastrointestinal stromal tumours (GIST) and to evaluate the performance of a risk-based surveillance protocol in detection of recurrence. METHODS: Eighty-one patients on surveillance following complete resection of GIST were included. Patients were stratified into risk groups according to accepted histopathological criteria. Computed tomography (CT) examinations were retrospectively reviewed to determine rates, sites and imaging characteristics of recurrence and to assess compliance with the local follow-up protocol. RESULTS: The median time of follow-up was 41 months. Nineteen patients suffered recurrence, all of whom were in the high-risk group. Fifty-eight percent of relapses occurred within 1 year and 84% within 3 years. Even within the high-risk group, patients with relapse had significantly larger (mean 15 versus 10.4 cm, p < 0.05) and more mitotically active primary tumours (mean 33.7 versus 5.6 mitoses per 50 high-power fields; p < 0.05) than those with no relapse. Relapse was to the liver in 12 cases (63%) and to the omentum and mesentery in nine cases (47%), and was asymptomatic in three-quarters of patients. CONCLUSIONS: The high incidence of GIST recurrence in the high-risk group in the first 3 years after surgery supports the use of intensive imaging surveillance in this period. Relapse is often asymptomatic and commonly occurs to the liver, omentum and mesentery. Stratification by tumour factors may enable improved tailoring of surveillance protocols within the high-risk group in the future.