e20129 Background: Small cell lung cancer (SCLC) is an aggressive malignancy with historically poor survival outcomes. While advances in radiation therapy, diagnostics, and supportive care have led to gradual gains, core systemic treatment options remained largely unchanged for decades, particularly for extensive-stage (ES) disease. The introduction of immune checkpoint inhibitors (ICIs) into first-line therapy in 2018 represented the most significant therapeutic advancement in SCLC in over 30 years. Whether this paradigm shift has translated into population-level survival improvements across all disease stages remains unclear. Methods: We conducted a retrospective population-based cohort study using the Surveillance, Epidemiology, and End Results (SEER) database. Adults aged ≥18 years with histologically confirmed SCLC diagnosed between 2000 and 2021 were included. Diagnostic years were grouped into four treatment eras: 2000–2006, 2007–2011, 2012–2016, and 2017–2021. Stage at diagnosis was defined using SEER Summary Stage. Localized and regional disease were categorized as limited-stage SCLC, while distant disease was classified as extensive-stage SCLC. Overall survival (OS) was calculated from diagnosis to death from any cause or last follow-up. Kaplan–Meier methods were used to estimate survival trends across eras. Results: A total of 76,472 patients with SCLC were identified, including 18,522 (24.2%) with limited-stage and 57,950 (75.8%) with extensive-stage disease at diagnosis. Among patients with limited-stage SCLC, five-year OS improved steadily over time, increasing from 10.2% (95% CI, 9.3–11.3) in 2000–2006 to 12.5% (95% CI, 11.6–13.4) in 2007–2011, 15.5% (95% CI, 14.5–16.5) in 2012–2016, and 18.1% (95% CI, 16.7–19.6) in 2017–2021.In extensive-stage SCLC, 5 year OS remained low but demonstrated improvement over time: 2.0% (95% CI: 1.7%-2.2%) in 2000-2006, 2.0% (95% CI: 1.8%-2.2%) in 2007-2011, 2.3% (95% CI: 2.1%-2.5%) in 2011-2016, 3.6% (95% CI: 3.2%-4.1%) in 2017-2021 with the largest increase seen after 2017. Conclusions: In this large national analysis, long-term survival among patients with SCLC improved modestly over the past two decades. Incremental gains likely reflect advances in staging accuracy with PET–CT imaging, refinements in radiation delivery, and improvements in supportive care that enhance treatment tolerance. The most pronounced survival improvement was observed in extensive-stage disease after 2017, potentially corresponding with the incorporation of immune checkpoint inhibitors into frontline therapy—the first systemic treatment in more than 30 years to demonstrate a meaningful overall survival benefit in SCLC. Despite these advances, five-year survival remains poor across all stages, highlighting the need for more effective therapeutic strategies and improved implementation of emerging treatments at the population level.
Barsoum et al. (Thu,) studied this question.