HER2 status in lung adenocarcinoma: A comparison of immunohistochemistry, fluorescence in situ hybridization (FISH), dual-ISH, and gene mutations

Highlights • We analyzed HER2 alterations in patients with lung adenocarcinoma by using four methods and explored the concordance of these methods. • HER2 protein overexpression, gene amplification, and gene mutations appeared to be uncommon in lung adenocarcinoma. • Cases with HER2 mutations tended to show HER2 gene amplification. • DISH was better than FISH for detection of cases with HER2 amplification. • HER2 gene amplification and mutations should be tested to determine whether patients with lung adenocarcinoma are eligible for administration of new anti-HER2 agents.