Systemic therapy for small cell lung cancer.

Small cell lung cancer is an aggressive tumor characterized by genetic complexity, rapid doubling time, and early development of disseminated disease. Unfortunately, few chemotherapeutic advances have been made in the treatment of extensive-stage disease, and cisplatin/etoposide has remained the standard of care for more than 30 years. Other regimens with comparable efficacy include cisplatin/irinotecan and carboplatin/etoposide. Each of these combinations is associated with a different toxicity profile that must be considered when selecting an initial regimen. Several strategies, including maintenance chemotherapy, 3-drug combinations, alternating combination chemotherapy regimens, and high-dose chemotherapy, have consistently failed to demonstrate improvements in survival when compared with 4 to 6 cycles of platinum doublets. Several options are available for patients who experience progression during or relapse after induction therapy, although topotecan is the only FDA-approved agent for second-line treatment. Recently, scientific efforts have identified potentially actionable genetic alterations in small cell tumors that may lead to the development of effective, targeted therapies.