Role of topoisomerase I inhibitors in small-cell lung cancer

Lung cancer continues to be the leading cause of cancer-related death in the United States. Small-cell lung cancer constitutes 15%-20% of all cases of lung cancer. It is a chemosensitive disease with an overall response rate of 70%-90% in first-line treatment. However, the majority of patients relapse, and further treatment at that time is unlikely to achieve a durable response. Among the new drugs studied in this disease, topoisomerase I inhibitors are emerging as active agents with significant activity in both untreated and relapsed disease. This paper reviews the current status of irinotecan and topotecan in the treatment of small-cell lung cancer.