Changing epidemiology of small-cell lung cancer in the United States over the last 30 years: analysis of the surveillance, epidemiologic, and end results database.

PURPOSE: Small-cell lung cancer (SCLC) is a histologic subtype of lung cancer with a distinct biology and clinical course. It has been observed that the incidence of SCLC has been decreasing over the last several years.

METHODS: We used the Surveillance, Epidemiologic, and End Results (SEER) database to determine the incidence of SCLC over the last 30 years. In addition, we sought to determine sex- and stage-based differences in the incidence and survival of SCLC among a proportion of reported cases of lung cancer over the last 30 years (1973 to 2002). Joinpoint analyses were applied to test the trends in annual percentage change for statistical significance.

RESULTS: The proportion of SCLC (among all lung cancer histologic types) decreased from 17.26% in 1986 to 12.95% in 2002. Of all patients with SCLC, the proportion of women with SCLC increased from 28% in 1973% to 50% in 2002. A modest but statistically significant improvement in 2- and 5-year survival was noted among both limited-stage SCLC and extensive-stage SCLC cohorts during the study period.

CONCLUSION: Our analysis indicates that the incidence of SCLC is decreasing in the United States, and only modest improvements have been seen in survival over the last 30 years. Possible explanations for the decreasing incidence include the decrease in the percentage of smokers and the change to low-tar filter cigarettes. Despite trends toward modest improvement in survival, the outcome remains very poor.