High epidermal growth factor receptor amplification rate but low mutation frequency in Middle East lung cancer population.
Epidermal growth factor receptor (EGFR) exon 18-21 mutations were shown to be highly predictive of response to gefitinib (Iressa) therapy in lung cancer. Studies on Western and Japanese lung cancers have indicated substantial differences in the EGFR mutation frequency between these populations. To investigate the prevalence of EGFR in another distinct ethnic group, EGFR alterations were studied in 47 consecutive non small cell lung cancers from Saudi Arabia by immunohistochemistry, fluorescence in situ hybridization, and DNA sequencing. Detectable EGFR expression was seen in 69.8% of 43 interpretable cancers. Epidermal growth factor receptor amplification, present in 15.3% of 39 analyzable cancers, was strongly associated with high levels of EGFR expression (P = .0047). Only 1 exon 18-21 mutation was seen among 34 lung cancers that could be successfully sequenced. It is concluded that EGFR exon 18-21 mutations are rare in Middle East patients with lung cancer and occur in a similar range as in Western patients. The remarkable high rate of EGFR gene amplifications could potentially facilitate studies on the predictive role of gene copy number changes for response to anti-EGFR therapies in Middle East patient sets.
Al-Kuraya
Khawla
K
King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.
Siraj
Abdul K
AK
Bavi
Prashant
P
Al-Jommah
Naif
N
Ezzat
Adnan
A
Sheikh
Salwa
S
Amr
Samir
S
Al-Dayel
Fouad
F
Simon
Ronald
R
Guido
Sauter
S
D000230:Adenocarcinoma / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism; D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D015331:Cohort Studies; D004252:DNA Mutational Analysis; D004273:DNA, Neoplasm / Q000032:analysis; D066246:ErbB Receptors / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D005260:Female; D000077156:Gefitinib; D005784:Gene Amplification; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008175:Lung Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011799:Quinazolines / Q000627:therapeutic use; D012529:Saudi Arabia; D046888:Tissue Array Analysis
D000970:Antineoplastic Agents; D004273:DNA, Neoplasm; D011799:Quinazolines; D066246:ErbB Receptors; D000077156:Gefitinib