HER2/neu expression in malignant lung tumors.
Despite intensive treatment efforts, the prognosis for lung cancer is very poor; less than 15% of patients survive 5 years. Trastuzumab, a monoclonal antibody targeting the HER2/neu protein receptor, is effective in the treatment of metastatic breast cancer and may be useful in the treatment of non-small cell lung cancer (NSCLC). Using the HercepTest (Dako; Carpenteria, CA), 25% of NSCLC show 2+ or greater HER2/neu expression, but only 6% to 8% of NSCLC tumors have 3+ overexpression. Positive HER2/neu expression is most often seen in adenocarcinomas compared with squamous cell carcinomas or large cell carcinomas, and is rarely seen in small cell lung cancer. As determined by fluorescence in situ hybridization analysis, the high degree of HER2/neu gene expression and gene amplification seen in breast cancer is lower in NSCLC. Polysomy is the cause of increased HER2/neu expression in most NSCLC. Prospective clinical studies with trastuzumab in lung cancer are ongoing. Future studies in NSCLC need to include immunohistochemistry and fluorescence in situ hybridization analysis to determine the method of choice for evaluating clinically relevant HER2/neu-positive tumors.
Hirsch
Fred R
FR
Lung Cancer Program, Department of Pathology, University of Colorado Cancer Center, Denver, CO 80262, USA.
Franklin
Wilbur A
WA
Veve
Robert
R
Varella-Garcia
Marileila
M
Bunn
Paul A
PA
D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000235:genetics / Q000503:physiopathology; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000235:genetics* / Q000503:physiopathology; D002986:Clinical Trials as Topic; D005784:Gene Amplification; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008175:Lung Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000503:physiopathology; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis*; D000068878:Trastuzumab; D015854:Up-Regulation
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab