Trends in the Incidence and Survival Outcomes in Patients With Small Cell Lung Cancer in the United States: An Analysis of the SEER Database

BACKGROUND: There has been a lack of updated epidemiological data on the incidence and survival outcomes for patients with small cell lung cancer (SCLC) in the United States over the last two decades. METHODS: A retrospective, population-based study was conducted utilizing the Surveillance, Epidemiology, and End Results (SEER) program to identify patients with SCLC from 2000 to 2020. Trends in cancer incidence, incidence-based mortality rates, 1-year relative survival rates and 1-year observed survival were evaluated utilizing the SEER database. RESULTS: The database identified a total of 188,426 SCLC patients during the study period from 2000 through 2020. The age-adjusted incidence rate slowly declined, on average, by 3% (95% CI: -3.2% to -2.8%) each year from 9 per 100,000 in 2000 to 4.6 per 100,000 in 2020. The decline is evident for all age groups, sexes, and races. Incidence-based mortality also declined slowly from 6.6 in 2005 to 3.5 in 2020. However, survival outcomes, including 1-year relative survival and 1-year observed survivals, have not improved significantly over the last two decades. CONCLUSION: This study found that the incidence of SCLC has decreased from 2000 to 2020, likely due to a reduction in smoking rates, underscoring the importance of smoking abstinence. An improvement in incidence-based mortality is likely related to an enhanced medical care and a decrease in the incidence of SCLC, but the lack of improvement in survival outcomes reflects the need for more effective systemic therapy.