Survival After Treatment of Small-Cell Lung Cancer: an Endless Uphill Battle

Extract

The evidence linking tobacco exposure with cancer of the aerodigestive tract is incontrovertible and inarguable. The lethality of this potent carcinogen is best reflected in the death rates from lung cancer, which represent only a portion of tobaccorelated cancer deaths. In the United States, the number of deaths from lung cancer in 1997 will exceed those from breast, prostate, and colon cancers combined, despite a much lower incidence of lung cancer overall ( 1 ). Tobacco's highly addictive properties and intensive marketing are the major factors in sustaining substantial worldwide tobacco use despite the clear danger it represents.

Of all lung cancers, small-cell, undifferentiated cancer is the type most strongly associated with tobacco, with only 3% of patients with this cancer having no history of active exposure ( 2 ). Metastatic small-cell lung cancer (SCLC) is rapidly fatal if untreated, producing death within 6–12 weeks. However, combination chemotherapy can prolong patient survival by several months. For patients with disease limited to the chest (nonmetastatic disease), the prospects for long-term survival are brighter and appear to be even better for those who receive etoposide/cisplatin-based chemotherapy and concurrent thoracic radiation ( 3 – 6 ). Two-year survival in these patients has exceeded 40% in several phase II trials and a recent phase III trial, approximately double the survival rate seen with alkylator- or anthracyclinebased therapies, older treatments that are inherently more difficult to combine with thoracic radiation therapy ( 7 ). This modicum of success in treating limited SCLC is, however, diminished in these survivors by the high rate of death due to second primary cancers and many other causes, as reported by Tucker et al. ( 8 ) in this issue of the Journal.