1489P - Final results of a French Sarcoma Group (FSG) retrospective review of 110 patients with primary localized gastrointestinal stromal tumors (GIST) of...
|Date||29 September 2012|
|Event||ESMO Congress 2012|
|Session||Poster presentation I|
F. Duffaud1, T. Huynh1, P. Cassier2, E. Boucher3, O. Bouché4, A. Le Cesne5, B. Landi6, J. Mancini7, F. Marchal8, J. Blay2
Duodenal GISTs represent 3-5% of all GISTs, with limited understanding of patient outcomes from small series. We conducted a retrospective analysis of localized duodenal GISTs over the past 18 years.Methods
Patients (pts) were identified in 2 ways: a group of 101 pts reported via survey from 20 FSG centers, and a group of 9 pts included in the BFR14 trial.Results
Pts were: 55 females, 55 males, with a median age of 57 years (30-84), and median ECOG 0 (0-3). Abdominal pain, anemia, and overt GI bleeding were the most common symptoms. Tumors (T) originated mainly in D2 (41%), or D3 (27%), with a median size of 5 cm (1.5-30). All pts except four had resection of the primary T. Surgical procedures were: local resection (LR) [segmental duodenectomy (n = 31), wedge local resection (n = 31), local excision (n = 6)], and duodenopancreatectomy (DP, n = 20). Resections were R0 in 84 pts (79%), R1 in 6 pts (6%). T characteristics included: KIT+ (n = 100), CD34 + (n= 54), mitoses/50 HPF ≤ 5 (n= 70), or > 5 (n = 24), Miettinen low-risk (n = 37), and high-risk (n = 19), necrosis (n = 29), spindle cell (n = 84). Genotype was evaluated in 36 cases: KIT exon 11 mutant (n = 30), no mutation (n = 4), and KIT exon 9 mutant (n = 2). 12 pts received neoadjuvant imatinib (IM) therapy resulting in 6 PR, 3 SD, 1 PD. 17 pts received adjuvant IM therapy. With a median FU of 32 months (1-250), 95 pts (86%) are alive. Twenty-eight (26%) pts relapsed: 6 LR, and 26 metastases. The 4-year OS and EFS rates were 89.5% and 68.2 %. The 6-year OS and EFS rates were 89.5% and 36.5%. Univariate analysis showed that: age and ECOG PS have an impact on OS (p= 0.008, p <0.001), necrosis, spindle-cell type, T size, mitoses/50 HPF, and Miettinen risk were predictive of relapse (p< 0.001). In multivariate analysis tumor size and mitoses/ 50 HPF only were predictive of relapse (p< 0.001).Conclusions
Pts with resected duodenal GIST have a reasonably favourable prognosis. LR rather than DP should be pursued if possible to preserve optimal pancreas function. Neoadjuvant IM may potentially allow a proportion of patients requiring DP to undergo LR. Adjuvant IM should be systematically discussed with a patient based on his individual-risk of relapse.Disclosure
All authors have declared no conflicts of interest.