Immunotherapy Improves the Survival of Stage 4 Non–Small Cell Lung Cancer Patients at the US Population Level: The Real‐World Evidence

ABSTRACT Introduction Immunotherapy has revolutionized the management of lung cancer and improved lung cancer survival in trials, but its real‐world impact at the population level remains unclear. Methods Using data obtained from eight Surveillance, Epidemiology, and End Results (SEER) registries from 2004 through 2019, we addressed the long‐term trends in the incidence, incidence‐based mortality (IBM), and survival of lung cancer patients in the United States. Results The incidence and IBM of both non–small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) all significantly decreased steadily from 2004 to 2019. The 1‐year survival (1‐YS) of both NSCLC and SCLC improved over time, with the best improvement observed for Stage 4 NSCLC. Two significant turning points of Stage 4 NSCLC 1‐YS were observed over the years: 0.63% (95% confidence interval [CI]: 0.33%–0.93%) from 2004 to 2010, 0.81% (95% CI: 0.41%–1.21%) from 2010 to 2014 and a striking 2.09% (95% CI: 1.70%–2.47%) from 2014 to 2019. The same two turning points in 1‐YS were pronounced for Stage 4 NSCLC in women, which were coincident with the introduction of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR‐TKIs) and immunotherapy. However, for Stage 4 NSCLC in men, only one significant turning point in the 1‐YS starting in 2014 was found, which might only correspond to immunotherapy. Significant period effects in reduced IBM were also observed for both Stage 4 AD and Stage 4 SQCC during the period. Conclusion This SEER analysis found that immunotherapy improved the survival of Stage 4 NSCLC patients at the population level in the United States. This real‐world evidence confirms that immunotherapy has truly revolutionized the management of lung cancer.