[Immunohistochemical detections of EGFR status in NSCLC].
BACKGROUND
Patients with non-small cell lung cancer (NSCLC) harboring mutations of the epidermal growth factor receptor (EGFR) respond well to EGFR-tyrosine kinase inhibitor therapy. Immunohistochemistry (IHC) is a simple and widely used technique in clinical pathology laboratories. IHC also features cost effectiveness and rapid detection of EGFR mutations compared with molecular methods. This study aims to determine the accuracy of IHC for EGFR mutation detection in NSCLC.


METHODS
Specimens (obtained from surgery or biopsy) from 97 NSCLC cases were stained through IHC with mutation-specific antibodies. The clinicopathological features of patients with positive immunostaining results were analyzed. Positive specimens were subjected to liquid chip technology to detect the actual EGFR status. Forty NSCLC specimens obtained from surgery and confirmed to have EGFR mutations through liquid chip technology were collected. These specimens were then subjected to IHC analyses with mutation-specific antibodies. The sensitivity of IHC in detecting EGFR mutations was calculated.


RESULTS
Seventeen of the 97 NSCLC specimens were stained positive, and positive results were mostly observed in females, patients with adenocarcinoma, and non-smokers. About 76.9% of specimens with positive IHC results harbored mutations. The sensitivity of IHC was 40% among the 40 cases identified as containing EGFR mutations through liquid chip technology.


CONCLUSIONS
The strong positive immunostaining result is accurate, but the sensitivity of the method may not be optimal and significantly varies in different studies. The widespread application of IHC in clinics must be further investigated.
Department of Medical Oncology, Tianjin Medical University General Hospital, Tianjin 300052, China.
Jie
J
Wang
Department of Medical Oncology, Tianjin Medical University General Hospital, Tianjin 300052, China.
Chang
C
Liu
Department of Medical Oncology, Tianjin Medical University General Hospital, Tianjin 300052, China.
Diansheng
D
Zhong
Department of Pathology, Tianjin Medical University, Tianjin 300070, China.
Dongbo
D
Xu
Department of Medical Oncology, Tianjin Medical University General Hospital, Tianjin 300052, China.
Chao
C
Ning
Department of Medical Oncology, Tianjin Medical University General Hospital, Tianjin 300052, China.
Qing
Q
Ma
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D066246:ErbB Receptors / Q000235:genetics* / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D008175:Lung Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009154:Mutation
D066246:ErbB Receptors