Significance of EGFR protein expression and gene amplification in non-small cell lung carcinoma.
We evaluated epidermal growth factor receptor (EGFR) protein expression by immunohistochemical analysis and EGFR gene amplification by fluorescence in situ hybridization in 199 consecutive newly diagnosed and surgically treated patients with primary non-small cell lung carcinoma (NSCLC) and correlated results with clinicopathologic findings. EGFR protein expression was more common in squamous cell carcinoma (SCC; 17 [26.2%]) than in adenocarcinoma (14 [11.1%]; (P = .0076) and more frequently associated with EGFR amplification (8 [14.5%] vs 4 [3.6%] cases; P = .0208). Poor differentiation was associated with a higher average number of EGFR gene copies per cell (mean, 4.18; P = .0322) and a higher EGFR/chromosome 7 ratio (mean, 1.84; P = .0324). N0 disease showed a higher number of EGFR gene copies (mean, 4.196; P = .0163). SCCs demonstrated a higher EGFR/chromosome 7 ratio than adenocarcinomas (mean, 1.95 vs 1.47; P = .0324), particularly T1 tumors (mean, 1.79; P = .0243). Statistical analysis failed to show correlation between outcome and EGFR protein expression and gene amplification in early NSCLC. EGFR protein expression was uncoupled from gene amplification in most cases, although good correlation occurred in a subset of SCCs.
Dacic
Sanja
S
Department of Pathology, Division of Anatomic Pathology, University of Pittsburgh Medical Center, Presbyterian University Hospital, Pittsburgh, PA 15213, USA.
Flanagan
Melina
M
Cieply
Kathleen
K
Ramalingam
Suresh
S
Luketich
James
J
Belani
Chandra
C
Yousem
Samuel A
SA
D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism / Q000556:secondary; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D018287:Carcinoma, Large Cell / Q000235:genetics / Q000378:metabolism / Q000556:secondary; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics / Q000378:metabolism* / Q000556:secondary; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000378:metabolism / Q000556:secondary; D002897:Chromosomes, Human, Pair 7; D018572:Disease-Free Survival; D066246:ErbB Receptors / Q000235:genetics* / Q000378:metabolism*; D005784:Gene Amplification; D018628:Gene Dosage; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D008875:Middle Aged; D009367:Neoplasm Staging; D011446:Prospective Studies
D014408:Biomarkers, Tumor; D066246:ErbB Receptors