Prognostic relevance of KIT and PDGFRA mutations in gastrointestinal stromal tumors.
BACKGROUND
Prediction of biological behavior is crucial for selection of new therapeutic modalities in GIST. Here, we aimed to assess whether KIT and PDGFRA mutations have survival impact in gastrointestinal stromal tumors (GIST).


METHODS
Fifty-five Brazilian patients with completely resected GIST were examined for KIT and PDGFRA mutations. The 5-year disease-free survival (DFS) was analyzed.


RESULTS
KIT and PDGFRA mutations were identified in 74.5% and 7.3% of patients, respectively. The 5-year DFS rate for all patients was 52.8%. The 5-year DFS rate was lower in patients with tumors having in-frame deletions or concomitant in-frame deletions and insertions affecting codons 557-558 than in patients with tumors having other exon 11 KIT mutations (p=0.023). Conversely, when the patients with concomitant deletion-insertion mutations affecting codons 557-558 were excluded from the analysis, deletions involving codons 557-558 had no influence on 5-year DFS rates.


CONCLUSIONS
Our findings indicate that a specific KIT mutation may be associated with unfavorable behavior in GIST. This finding may have implications on selecting patients for adjuvant therapy.
Braggio
Esteban
E
Center of Bone Marrow Transplantation (CEMO), Instituto Nacional de Câncer (INCA), Rio de Janeiro, Brazil.
Braggio
Danielle De Almeida
Dde A
Small
Isabele Avila
IA
Lopes
Lisandro F
LF
Valadão
Marcus
M
Gouveia
Maria Emmerick
ME
Moreira
Aline Dos Santos
Ados S
Linhares
Eduardo
E
Romano
Sérgio
S
Bacchi
Carlos E
CE
Renault
Ilana Zalcberg
IZ
Guimarães
Denise Peixoto
DP
Ferreira
Carlos Gil
CG
D000328:Adult; D000368:Aged; D003062:Codon; D005091:Exons; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011379:Prognosis; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics*; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000235:genetics*
D003062:Codon; D019009:Proto-Oncogene Proteins c-kit; D020796:Receptor, Platelet-Derived Growth Factor alpha