Increased vascular-endothelial growth factor (VEGF) tumor expression and response to epidermal growth factor receptor (EGF-R) inhibitor erlotinib in non-small cell lung cancer (NSCLC).

A 37-year-old female never smoker with metastatic large cell carcinoma of the lung had a partial response to a second line palliative therapy with the EGF-R tyrosine kinase inhibitor erlotinib after platinum based first line therapy failed. Molecular analysis of the primary and a liver metastasis did neither find any EGF-R mutation nor an EGF-R amplification. However, both the primary and the metastasis showed an increased gene expression of vascular-endothelial growth factor-A in contrast to normal tissue, which was confirmed by immunohistochemistry. To our knowledge, this is the first report about a high vascular-endothelial growth factor-A expression in the tumor of a patient responding to an EGF-R inhibitor postulating that there might be a link between both tyrosine kinase pathways.