Haodong Xu
University of California at Los Angeles, USA
Title: Immunohistochemical Detection of EGFR Mutations and ALK Rearrangement in Lung Adenocarcinoma
Biography
Biography: Haodong Xu
Abstract
Epidermal growth factor receptor (EGFR) gene mutational analysis and anaplastic lymphoma kinase (ALK) gene rearrangement detection are standard for guiding the treatment of advanced-stage lung adenocarcinoma. The lung biopsy specimens may contain a limited number of tumor cells for extracting enough DNA for gene mutational analysis, or performing fluorescence in-situ hybridization (FISH)to determine the genetic translocation.Immunohistochemistry (IHC) may be an alternative approach. Studies were performed to further validate the sensitivity and specificity of the antibodiesagainst EGFR with del E746-A750 in exon 19 and L858R in exon 21 or ALK, and to determine if the immunostaining withthese antibodies is a reliable screening method in the detection of these two genes’ abnormalities in the biopsied and resected lung adenocarcinomas. Sections from the tumor specimens were immunostained with these antibodies and the same specimens were used for DNA purification, analysis for EGFR mutations, and FISH for the detection of ALK rearrangement with break-apart probes. Based on the molecular testing, the overall sensitivity and specificity are high for antibodies against EGFR with del E746-A750 and L858R mutations and ALK. IHC is a very useful screening method for detecting EGFR gene mutation and ALK gene rearrangement.