Fernando Azevedo Pacheco, Marcos Eduardo Machado Paschoal, Maria da Glória da Costa Carvalho
Recent advances in genetics and molecular biology lead to the identification of genes and protein products overexpressed by tumors. Such products, called tumor markers, were previously used only as diagnostic and prognostic tools, but are currently being the target of extensive research, with growing evidence that some of them may have an important role in the development of new treatment modalities, targeting the tumor cell biological cycle. In this article, the authors review the role of some of the traditionally known tumor markers (CEA, p53, NSE, K-ras), and describe the prevalence and the role of the epidermal growth factor receptor (EGFR) overexpression and its protein product, p185neu. New drugs have been developed, aiming at the blockade of the signaling process initiated by the EGFR. Among these, the authors highlight ZD1839 (Iressa), a new orally administered drug that reversibly and selectively inhibits the EGFR tyrosine-kinase activity. This drug has demonstrated good results in the treatment of non-small-cell lung cancer, as an isolated drug or in combination with other chemotherapy agents. Targeting the EGFR could represent a significant contribution to cancer therapy, mainly the non-small-cell lung cancer.
Keywords: Lung neoplasms. Tumor markers. Receptor epidermal growth factor.