Gastrointestinal stromal tumours: incidence, recurrence and mortality. A decade of patients from a New Zealand tertiary surgical centre.

BACKGROUND

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the gastrointestinal tract. The New Zealand (NZ) population incidence has not previously been documented nor has the potential effect of ethnicity been reviewed. We furthermore wanted to assess the difference between those undergoing a wedge resection versus a more extensive operation which we hypothesised would correlate with recurrence and mortality.

METHODS

All patients (n = 103) with a GIST diagnosed and treated at Te Whatu Ora Waitematā (Auckland, New Zealand) between 2012 and 2021 are presented. Patient demographics, method of GIST detection, management approach, index surgery, histological features, use of adjuvant and neoadjuvant imatinib, follow-up, recurrence and mortality rates were analysed.

RESULTS

This paper reports the largest NZ GIST cohort to date and estimates an incidence of 17 cases per million per year. Eighty-four patients underwent surgical resection, 58 received a wedge resection and 17 received a more extensive operation. Five-year disease-free survival rates were 100% in the low/very low risk, 90% in the intermediate and 59% in the high risk groups as determined by the modified NIH criteria. Our overall 5-year GIST-specific survival rate was 83%; it was 91% in those who underwent a wedge resection and 60% in the extensive operation group. There is evidence that Māori have higher rates of GIST recurrence compared to non-Māori and are more likely to require an extensive surgical resection.