Novel targets for therapeutic agents in small cell lung cancer.

Small cell lung cancer (SCLC) is known to have an aggressive phenotype and often presents with distant metastasis. Despite frequent initial response to chemotherapy, it inevitably relapses within 2 years in the majority of patients. Because of the poor overall prognosis of the disease and its unique tumor biology, the opportunity for improving clinical outcome of patients with development of novel therapeutics is great. This review provides current insights into the novel molecular targets in SCLC. Cellular signal transduction pathways and their relationship to cellular functions also are discussed. Discussion of the role receptor tyrosine kinases (RTKs) have in SCLC therapeutic inhibition is emphasized. In particular, the recent development of small molecule inhibitors of RTKs such as c-Kit, c-Met, and VEGF-R and the potential for clinical trials are highlighted.