Epidermal growth factor receptor mutations and gene amplification in non-small-cell lung cancer: molecular analysis of the IDEAL/INTACT gefitinib trials.
OBJECTIVE
Most cases of non-small-cell lung cancer (NSCLC) with dramatic responses to gefitinib have specific activating mutations in the epidermal growth factor receptor (EGFR), but the predictive value of these mutations has not been defined in large clinical trials. The goal of this study was to determine the contribution of molecular alterations in EGFR to response and survival within the phase II (IDEAL) and phase III (INTACT) trials of gefitinib.


METHODS
We analyzed the frequency of EGFR mutations in lung cancer specimens from both the IDEAL and INTACT trials and compared it with EGFR gene amplification, another genetic abnormality in NSCLC.


RESULTS
EGFR mutations correlated with previously identified clinical features of gefitinib response, including adenocarcinoma histology, absence of smoking history, female sex, and Asian ethnicity. No such association was seen in patients whose tumors had EGFR amplification, suggesting that these molecular markers identify different biologic subsets of NSCLC. In the IDEAL trials, responses to gefitinib were seen in six of 13 tumors (46%) with an EGFR mutation, two of seven tumors (29%) with amplification, and five of 56 tumors (9%) with neither mutation nor amplification (P = .001 for either EGFR mutation or amplification v neither abnormality). Analysis of the INTACT trials did not show a statistically significant difference in response to gefitinib plus chemotherapy according to EGFR genotype.


CONCLUSIONS
EGFR mutations and, to a lesser extent, amplification appear to identify distinct subsets of NSCLC with an increased response to gefitinib. The combination of gefitinib with chemotherapy does not improve survival in patients with these molecular markers.
Bell
Daphne W
DW
Massachusetts General Hospital Cancer Center and Department of Pathology, Harvard Medical School, Charlestown, MA 02129, USA.
Lynch
Thomas J
TJ
Haserlat
Sara M
SM
Harris
Patricia L
PL
Okimoto
Ross A
RA
Brannigan
Brian W
BW
Sgroi
Dennis C
DC
Muir
Beth
B
Riemenschneider
Markus J
MJ
Iacona
Renee Bailey
RB
Krebs
Annetta D
AD
Johnson
David H
DH
Giaccone
Giuseppe
G
Herbst
Roy S
RS
Manegold
Christian
C
Fukuoka
Masahiro
M
Kris
Mark G
MG
Baselga
José
J
Ochs
Judith S
JS
Haber
Daniel A
DA
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor / Q000378:metabolism; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism; D066246:ErbB Receptors / Q000235:genetics*; D005260:Female; D000077156:Gefitinib; D005784:Gene Amplification; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011799:Quinazolines / Q000627:therapeutic use*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D015996:Survival Rate
D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D011799:Quinazolines; D066246:ErbB Receptors; D000077156:Gefitinib