Expression of EGFR mutation-specific antibody and its significance in lung adenocarcinoma / 临床与实验病理学杂志

Purpose To investigate the expression and significance of epiderma1 growth factor receptor( EGFR)mutation-specific anti-bodies in 1ung adenocarcinoma. Methods Immunohistochemica1( IHC)technique was used to detect the expression of EGFR muta-tion-specific antibodies(EGFR-19,EGFR-21)and EGFR tota1 protein antibody(EGFR-P)in 171 cases of 1ung adenocarcinoma with resected specimens,and EGFR gene mutation was a1so performed by amp1ification refractory mutation aystem-PCR( ARMS-PCR). The expression of EGFR-19,EGFR-21 and EGFR-P mutant proteins was compared with EGFR gene mutation and their re1ationship with histo1ogica1 c1assification and c1inica1 characteristics were ana1yzed. Results The expression of EGFR mutant protein was corre1ated with the poor differentiation group inc1uding micropapi11ary and so1id predominant types( P=0. 021 ). EGFR-21 high expression was re1ated to p1eura1 invasion(P=0. 005). The coherence of IHC(with EGFR-19/21 antibodies)and ARMS-PCR was existed(Kappa>0. 4 ). Taking ARMS-PCR as a standard,the sensitivity and specificity of EGFR-19 and EGFR-21 were 65. 0% and 89. 4%, 70. 0% and 97. 6%,respective1y. Conclusions Expression of EGFR mutation-specific antibodies is associated with poor differentia-tion and p1eura1 invasion. It suggests a worse prognosis indicator in 1ung adenocarcinoma. Because of the coherence with ARMS-PCR, using IHC with mutation-specific antibodies to detect the mutant proteins of EGFR-19/21 may act as a pre1iminary screening method of EGFR gene mutation.

Identification of EGFR Mutations by Immunohistochemistry with EGFR Mutation-Specific Antibodies in Biopsy and Resection Specimens from Pulmonary Adenocarcinoma / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Mutation-specific antibodies have recently been developed for identification of epidermal growth factor receptor (EGFR) mutations by immunohistochemistry (IHC). This study was designed to investigate whether the type of specimen (biopsy vs. resection) would make a difference in determining mutation status by IHC, and to evaluate whether biopsies are suitable for detection of mutant EGFR protein. MATERIALS AND METHODS: IHC was performed using mutation-specific antibodies for E746-A750 deletion (DEL) and L858R point mutation (L858R) in biopsies and tissue microarrays of resected tumors from 154 patients with pulmonary adenocarcinoma. Results were then compared with DNA sequencing data. RESULTS: Molecular-based assays detected EGFR mutations in 62 patients (40.3%), including 14 (9.1%) with DEL, and 31 (20.1%) with L858R. IHC with two mutation-specific antibodies showed a homogeneous staining pattern, and correctly identified EGFR mutation status in 89% (137/154). Overall (biopsy/resection) sensitivity, specificity, positive predictive value, and negative predictive value were 75.6% (78.3%/72.7%), 94.5% (90.9%/96.3%), 85% (78.3%/88.9%), and 90.4% (90.9%/89.7%), respectively. CONCLUSION: Our data showed that IHC using EGFR mutation-specific antibodies is useful for detection of EGFR mutations with high specificity and good sensitivity not only for resection specimens but also for biopsy materials. Therefore, IHC using EGFR mutation-specific antibodies may preclude a second biopsy procedure to obtain additional tissues for identification of EGFR mutations by molecular assays in biopsies from advanced cancer, particularly when tumor cells in the samples are limited.