PDGFRalpha gene mutation and protein expression in gastrointestinal stromal tumors.
OBJECTIVE
Mutation of the PDGFRalpha is a potential candidate in the pathogenesis of KIT wild-type gastrointestinal tumors (GISTs). In this study, we evaluated the prevalence of PDGFRalpha mutations and corresponding protein expression in GISTs, to determine their usefulness in obtaining a prognosis.


METHODS
Genomic DNA was extracted from paraffin-embedded tumor tissues from 194 GISTs. Exons 12, 14 and 18 of the PDGFRalpha were amplified and sequenced. Immunohistochemical staining was performed in 179 patients.


RESULTS
Mutations in the PDGFRalpha were detected in 6 (3.1%) patients, and were observed solely in KIT wild-type GISTs. Among the 6 patients with PDGFRalpha gene mutations, 5 patients with localized GISTs showed no relapse after resection during the 19- to 80-month follow-up period. Intensity of PDGFRalpha expression was classified as 0 in 26 (14.5%), 1+ in 69 (38.5%), 2+ in 71 (39.7%) and 3+ in 13 (7.3%) patients. Levels of PDGFRalpha expression showed no correlation with relapse-free survival.


CONCLUSIONS
PDGFRalpha mutations in GISTs were found to be rare in this Korean population. Although localized GISTs with PDGFRalpha mutations showed relatively good prognosis after resection, the difference was not statistically significant.
Department of Internal Medicine, Division of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Heung Moon
HM
Chang
Min-Hee
MH
Ryu
Hyoungnam
H
Lee
Se Jin
SJ
Jang
Jae-Lyun
JL
Lee
Tae Won
TW
Kim
Jeong Hwan
JH
Yook
Sung Tae
ST
Oh
Byung Sik
BS
Kim
Jung Shin
JS
Lee
Yoon-Koo
YK
Kang
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004252:DNA Mutational Analysis; D004273:DNA, Neoplasm; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007723:Korea; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011379:Prognosis; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000235:genetics* / Q000378:metabolism*; D016019:Survival Analysis
D004273:DNA, Neoplasm; D020796:Receptor, Platelet-Derived Growth Factor alpha