Second-line treatment of small-cell lung cancer.

Approximately 45,000 new cases of small-cell lung cancer were diagnosed in 2005 in the United States. Although response to first-time therapy is up to 90%, the majority of patients will ultimately relapse. Therefore, active second-line therapy is needed for this patient population. The only second-line treatment for small-cell lung cancer approved by the US Food and Drug Administration is topotecan. Other agents have been investigated and have shown modest efficacy. These include vinorelbine, irinotecan, etoposide, paclitaxel, and gemcitabine. Novel "targeted therapies" have shown disappointing results in this disease. Much of the recent work has focused on investigating alternative dosing and scheduling of topotecan. Combination therapies have also been investigated, and some have been shown to increase activity over single agents, but toxicity and quality of life variables are imperative in the treatment of this patient population.