Advances in chemotherapy for small cell lung cancer: single-agent activity of newer agents.

Small cell lung cancer (SCLC) is a common neoplasm with an extremely poor prognosis. Patients with extensive-stage disease have a 5-year survival rate of 1% to 2%. Identification of new active chemotherapy agents is of great importance for the development of more effective treatment for SCLC. Several new drugs that have established a role in the management of non-SCLC in the past decade are also active in SCLC. The mean response rates in untreated versus previously treated patients for these newer drugs are: 26% versus 14% for vinorelbine, 27% versus 14% for gemcitabine, 45% versus 29% for paclitaxel, 22% versus 25% for docetaxel, 39% versus 19% for topotecan, and 50% versus 16% to 24% for irinotecan. A comparison of the response rates of those agents to more established drugs (e.g., cisplatin and etoposide) suggests that the newer drugs are equally or more active in previously treated patients with SCLC. This activity is even more impressive because initial therapy during the past decade has almost always included platinum and/or an epipodophyllotoxin in the regimen. Furthermore, a recent randomized trial showed that the combination of a newer agent (irinotecan) with cisplatin was superior to a standard etoposide and cisplatin regimen in patients with newly diagnosed extensive-stage SCLC. These data support further evaluation of the newer chemotherapeutic drugs, and especially the camptothecins (irinotecan and topotecan) and the taxanes (paclitaxel and docetaxel), in the initial treatment of SCLC.