EGFR gene copy number gain is related to high tumor SUV and frequent relapse after adjuvant chemotherapy in resected lung adenocarcinoma.
OBJECTIVE
The purpose of our study was to define the prognostic impact of increased copies of epidermal growth factor receptor (EGFR) gene in lung adenocarcinoma patients receiving adjuvant chemotherapy after surgery.


METHODS
The study included 95 adenocarcinoma patients who received curative resection for non-small cell lung cancer. Patients received adjuvant chemotherapy composed of paclitaxel and carboplatin. We performed fluorescent in situ hybridization on tissue microarray in duplicate to detect EGFR copy number change.


RESULTS
The EGFR fluorescent in situ hybridization result was available in 93 patients with a positive rate of 32.6%. EGFR copy number change did not correlate with age, gender or smoking history. However, EGFR copy number gain was related to high tumor standardized uptake value at diagnosis (P = 0.042). An increase in EGFR copy number was a negative prognostic factor in terms of disease-free survival (median disease-free survival not reached versus 23.6 months, P = 0.037) and overall survival (median overall survival 74.6 versus 43.5 months, P = 0.032). An increase in EGFR copy number was independently related to short disease-free survival in multivariate analysis (hazard ratio 2.039, P = 0.025).


CONCLUSIONS
EGFR copy number gain is associated with aggressive tumor biology and is a poor prognostic factor for tumor relapse in resected lung adenocarcinoma patients receiving adjuvant chemotherapy of paclitaxel and carboplatin.
Department of Internal Medicine, Seoul National University Hospital, 101 Daehagro, Chongno-gu, Seoul 110-744, Republic of Korea.
Youngil
Y
Koh
Bogun
B
Jang
Yoon Kyung
YK
Jeon
Tae Min
TM
Kim
Se-Hoon
SH
Lee
Dong-Wan
DW
Kim
Doo Hyun
DH
Chung
Young Tae
YT
Kim
Young Whan
YW
Kim
Dae Seog
DS
Heo
D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000235:genetics* / Q000601:surgery; D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D016190:Carboplatin / Q000008:administration & dosage; D017024:Chemotherapy, Adjuvant; D015331:Cohort Studies; D056915:DNA Copy Number Variations; D018572:Disease-Free Survival; D066246:ErbB Receptors / Q000235:genetics*; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000235:genetics* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D017239:Paclitaxel / Q000008:administration & dosage; D011013:Pneumonectomy; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D011379:Prognosis; D040081:Protein Array Analysis; D012008:Recurrence
D016190:Carboplatin; D066246:ErbB Receptors; D017239:Paclitaxel