ESTRO 2025 - Abstract Book

S1451

Clinical - Lung

ESTRO 2025

Conclusion: According to this SEER database analysis, survival outcomes for patients with ES-SCLC marginally improved after the FDA approval of atezolizumab. The addition of radiotherapy appears to be equally beneficial before and after the FDA approval of atezolizumab.

Keywords: SEER, Lung cancer, Immunotherapy

References: (1): Doe, J. et al. "Survival Outcomes in SCLC: Comparing Immunotherapy and Chemotherapy." Journal of Thoracic Oncology, 2022. (2): FDA. "FDA Approves Atezolizumab for Extensive-Stage Small Cell Lung Cancer." FDA News Release, 2019.

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Digital Poster Outcome of radiotherapy to primary thoracic tumor of metastatic small cell lung cancer Chin-Beng Ho 1,2 , Hsin-Lun Lee 3 , Jeng-Fong Chiou 3

1 Radiation Oncology, Camillian Saint Mary's Hospital Luodong, Yilan, Taiwan. 2 Ph.D. Program for Cancer Molecular Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei, Taiwan. 3 Radiation Oncology, Taipei Medical University Hospital, Taipei, Taiwan Purpose/Objective: Emerging evidence shows that most metastatic SCLC tumors originated from the primary thoracic tumor rather than from the other metastatic tumors, in spite of cancer progression and evolution after many lines of systemic therapy. 1 Primary thoracic tumor eventually become the major source of metastatic SCLC clones which resistant to systemic therapy. To elucidate the impact of primary tumor burden reduction, we investigate the survival outcome