Surgical treatment of gastric GIST in the imatinib era

Surgical treatment of gastric GIST in the imatinib era
Stiekema J1, Kol S1, Cats A2, van Coevorden F1, van Sandick J1
1 the
Nederlands Cancer Institute – Antoni van Leeuwenhoek hospital, Surgical Oncology
the Nederlands Cancer Institute – Antoni van Leeuwenhoek hospital, Gastroenterology
The introduction of the tyrosine kinase inhibitor imatinib (Glivec) has profoundly
changed the treatment of gastrointestinal stromal tumours (GISTs). Neo-adjuvant
imatinib treatment is strongly advised in patients with locally advanced or marginally
resectable disease, where the risk of incomplete resection, tumour spill or significant
postoperative morbidity is high. In metastatic GIST imatinib is considered treatment of
primary choice, followed by secondary surgery in responding patients. In this study, the
outcome of patients who were operated for a gastric GIST with or without neo-adjuvant
imatinib was investigated.
All patients surgically treated for a gastric GIST at our institute in the past twelve years
(1999-2011) were included in this retrospective study. Patient, tumour, and treatment
characteristics were retrieved from written and electronic patient files.
A series of 48 patients was identified: 18 patients were treated with primary surgery
(group 1) and 30 patients received imatinib prior to surgery (group 2). The median
tumour size was 5.0 cm (range 1.5-19 cm) in group 1, and 13.5 cm (range 3.0-29 cm) in
group 2. Most patients had local disease, but one patient in group 1 and seven patients in
group 2 had metastatic GIST. Neo-adjuvant treatment led to a 25% reduction in tumour
size (p < 0.001). Complete resection (RO) was achieved in all patients in group 1, and 27
patients (90%) in group 2. Wedge, partial and total gastric resection was required in 7
(39%), 10 (56%) and none of the patients (0%) in group 1, against 3 (10%), 13 (43%)
and 4 patients (13%) in group 2. Multiple organ resection was performed in 1 patient
(5%) in group 1, and in 10 patients (34%) in group 2. Postoperative complications (0%
in group 1 and 20% in group 2; p= 0.043), were all transient with one complication in
group 2 necessitating a re-intervention. Stratified for extent of resection, there was no
significant difference in complication rate (p= 0.226). At a median follow-up of 30
months, 2 patients (11%) in group 1 and 5 patients (17%) in group 2 had recurrent or
progressive disease. This was seen exclusively in patients with R1 or R2 resection or
tumour spill during the operation. Five patients died of GIST. Median survival was not
yet reached in either group.
Conclusions: In this surgical series of gastric GIST patients, neo-adjuvant imatinib led to
a significant reduction in tumour size, with a non-significant increase in postoperative
complication rate. Considering the larger tumour size of patients in group 2, with a
historical poor prognosis, imatinib proved its value in our series in achieving a longer
progression free and overall survival.