Small cell lung cancer (SCLC) was diagnosed in 25,000 to 30,000 Americans during 1980, accounting for about 25% of all new cases of lung cancer. It is likely to remain a common disease unless the carcinogenic potential of the "low-tar" cigarettes proves to be substantially less than that of the higher "tar" cigarettes, which have been consumed in previous decades.
The median survival of patients with untreated SCLC ranges from seven to 14 weeks, depending on whether the disease is "extensive" or "limited" at the time of diagnosis. Extensive disease is said to be present when the disease has spread beyond one hemithorax and regional lymph nodes, or when there is a pleural effusion. The median survival of patients who are treated appropriately is now about nine months with extensive disease and 12 to 18 months with limited disease. More importantly, a fraction of the patients (probably less than 3%