Advanced NSCLC: from cytotoxic systemic chemotherapy to molecularly targeted therapy.

Approximately a third of non-small cell lung cancer patients present with disseminated disease at the time of diagnosis. For these patients, as well as those with recurrent disease, chemotherapy remains the mainstay of treatment. For several decades, researchers have attempted different combinations of drugs in search for the 'best' chemotherapy regimen. Despite the emergence of newer, 'third-generation' cytotoxic agents, success is still modest at best. Fortunately, new insights in tumor biology, leading to the design of molecularly targeted drugs, are opening a new era in cancer treatment. These novel agents target molecular pathways specifically found in cancer cells, thus maximizing the antitumor effect while minimizing toxicities on normal cells.