RT Journal Article T1 Phosphorylated-insulin growth factor I receptor (p-IGF1R) and metalloproteinase-3 (MMP3) expression in advanced gastrointestinal stromal tumors (GIST). A GEIS 19 study. A1 Maurel, Joan A1 López-Pousa, Antonio A1 Calabuig, Silvia A1 Bagué, Silvia A1 Del Muro, Xavier Garcia A1 Sanjuan, Xavier A1 Rubió-Casadevall, Jordi A1 Cuatrecasas, Miriam A1 Martinez-Trufero, Javier A1 Horndler, Carlos A1 Fra, Joaquin A1 Valverde, Claudia A1 Redondo, Andrés A1 Poveda, Andrés A1 Sevilla, Isabel A1 Lainez, Nuria A1 Rubini, Michele A1 García-Albéniz, Xabier A1 Martín-Broto, Javier A1 de Alava, Enrique AB Most GISTs have mutations in KIT or PDGFRA. Patients with advanced GIST with KIT exon 9, PDGFRA mutation or WT for KIT and PDGFRA have a worse progression-free survival (PFS) compared to patients with KIT exon 11 mutated tumors. We evaluated the immunohistochemical (IHC) expression of p-IGF1R (Y1316) and MMP3 as predictors of PFS or overall survival (OS). Ninety-two advanced GIST patients included in GEIS-16 study with KIT and PDGFRA mutational information were examined for p-IGF1R (Y1316) and MMP3 expression in a tissue micro-array. To study activation of the IGF1R system, we have used an antibody (anti-pY1316) that specifically recognizes the active phosphorylated form of the IGF1R. DNA was extracted from paraffin-embedded tissues and intronic PCR primers were used to amplify exons 9, 11, 13 and 17 of KIT, 12 and 18 of PDGFRA. Bidirectional sequencing with specific primers was performed on a ABI3100 sequencer using the Big Dye Terminator v3.1 kit. Multivariate model was built using a stepwise automated variable selection approach with criterion to enter the variable in the model of p  Phospho-IGF1R was expressed only in 9 % (2/22) of cases without KIT mutation. MMP3 expression was detected in 2/5 patients (40 %) with PDGFRA mutation, 1/16 patients (6 %) with WT genotype and 7/71 patients (10 %) of KIT mutant patients. At univariate analysis KIT exon 11/13 mutation had better PFS than patients with exon 9 mutation, PDGFRA mutation or WT genotype (p = 0.021; HR: 0.46; 95 %CI (0.28-0.76). Less than 24 months disease free-interval (HR 24.2, 95 % CI 10.5-55.8), poor performance status (PS) (HR 6.3, 95 % CI 2.5-15.9), extension of disease; >1 organ (HR 1.89; 95 % CI 1.03-3.4) and genotype analysis (HR 0.57, 95 % CI 0.37-0.97) but not immunophenotype analysis (HR 1.53; 95 % CI 0.76-3.06) were the strongest prognostic factors for PFS in the multivariate analysis. Our results do not support p-IGF-1R and MMP3 evaluation in non-selected GIST patients but evaluation of this immunophenotype in WT and mutant PDGFR mutation in larger group of GIST patients, deserve merits. SN 2045-3329 YR 2016 FD 2016-06-29 LK https://hdl.handle.net/10668/27773 UL https://hdl.handle.net/10668/27773 LA en DS RISalud RD Apr 4, 2025