Clinicopathologic characteristics of the EGFR gene mutation in non-small cell lung cancer.
BACKGROUND
The authors sought to define clinicopathologic features associated with mutations of the epidermal growth factor receptor (EGFR) gene in non-small cell lung cancer (NSCLC).


METHODS
The authors evaluated surgically resected NSCLC tumors for EGFR (exons 18-21) and KRAS (codons 12-13) mutations and immunohistochemistry (EGFR, phosphorylated-EGFR, and HER2/Neu), and correlated results with clinical outcome and patient and disease features. After their analysis on 159 patients was completed, they selected a second cohort of Asian patients (n = 22) and compared EGFR mutation results to place of birth and immigration to the United States.


RESULTS
Of 159 patients, 14 had EGFR mutations and 18 had KRAS mutations. EGFR mutations were associated with adenocarcinoma (p = 0.002), female gender (p = 0.02), never-smoking (p < 0.0001), Asian ethnicity (p = 0.005), air bronchograms (p = 0.004), and multiple wedge resections (p = 0.03). Although statistical significance was not reached, a higher incidence of synchronous primary cancers (36% versus 17%; p = 0.09) and a smaller median tumor size (11.8 cm versus 24.0 cm; p = 0.24) were seen. There was no difference in disease-free survival; however, median overall survival in patients with EGFR mutations was shorter (3.49 versus 4.29 years; p = 0.85). EGFR mutation did not correlate with immunohistochemistry. In the second cohort of 22 Asian patients, 12 (55%) had the mutation. Of interest, there was no geographic difference in incidence of EGFR mutation. Asian women with the EGFR mutation developed adenocarcinoma at an earlier age than other lung cancer patients.


CONCLUSIONS
There is a distinct clinical profile for NSCLC patients with the EGFR mutation. However, this mutation does not alter disease-free survival and is likely attributable to an inherited susceptibility instead of an environmental effect.
Tsao
Anne S
AS
Department of Thoracic/Head & Neck Medical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030-4009, USA.
Tang
Xi Ming
XM
Sabloff
Bradley
B
Xiao
Lianchun
L
Shigematsu
Hisayuki
H
Roth
Jack
J
Spitz
Margaret
M
Hong
Waun Ki
WK
Gazdar
Adi
A
Wistuba
Ignacio
I
D000230:Adenocarcinoma / Q000235:genetics; D002282:Adenocarcinoma, Bronchiolo-Alveolar / Q000235:genetics; D000328:Adult; D001741:Black or African American; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D002289:Carcinoma, Non-Small-Cell Lung / Q000208:ethnology / Q000235:genetics* / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000235:genetics; D066246:ErbB Receptors / Q000235:genetics*; D005091:Exons; D005260:Female; D006630:Hispanic or Latino; D006801:Humans; D008175:Lung Neoplasms / Q000208:ethnology / Q000235:genetics* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016283:Proto-Oncogene Proteins p21(ras); D016019:Survival Analysis; D014481:United States; D044465:White People; D018631:ras Proteins
C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D066246:ErbB Receptors; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins