Distribution and prognostic value of histopathologic data and immunohistochemical markers in gastrointestinal stromal tumours (GISTs): An analysis of the EORTC phase III trial of treatment of metastatic GISTs with imatinib mesylate.
BACKGROUND
The 62005 EORTC phase III trial, comparing two doses of imatinib in patients with advanced GIST, reported a median progression-free survival of 25 months with a trend towards dose dependency for progression-free survival. The current analysis of that study aimed to assess whether histological/immunohistochemical parameters correlate with clinical response to imatinib.


METHODS
Pre-treatment samples of GISTs from 546 patients enroled in phase III study were analysed for immunohistochemical characteristics, correlations with clinicopathological data, with survival and with tumours' genotype.


RESULTS
There was no correlation between immunomorphological or clinical characteristics and response to treatment, PFS or OS. No correlations between immunophenotype of the tumour and PFS or OS in the two dose arms were observed.


CONCLUSIONS
The results confirm the heterogeneity of GIST in terms of immunophenotypic expression, but indicate that these parameters have no impact on the outcome of the patients under imatinib treatment.
Sciot
Raf
R
Department of Pathology, Catholic University of Leuven, University Hospital Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium. Raf.Sciot@uz.kuleuven.be
Debiec-Rychter
Maria
M
Daugaard
Soren
S
Fisher
Cyril
C
Collin
Francoise
F
van Glabbeke
Martine
M
Verweij
Jaap
J
Blay
Jean-Yves
JY
Hogendoorn
Pancras C W
PC
D018952:Antigens, CD34 / Q000378:metabolism; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D001549:Benzamides; D018572:Disease-Free Survival; D004305:Dose-Response Relationship, Drug; D005091:Exons; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000188:drug therapy* / Q000235:genetics; D006801:Humans; D000068877:Imatinib Mesylate; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D008297:Male; D009154:Mutation / Q000235:genetics; D010879:Piperazines / Q000008:administration & dosage*; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics / Q000378:metabolism; D011743:Pyrimidines / Q000008:administration & dosage*; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000235:genetics
D018952:Antigens, CD34; D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate; D019009:Proto-Oncogene Proteins c-kit; D020796:Receptor, Platelet-Derived Growth Factor alpha