CASE REPORT article
Front. Oncol.
Sec. Thoracic Oncology
Volume 15 - 2025 | doi: 10.3389/fonc.2025.1651248
This article is part of the Research TopicTailored Strategies for Lung Cancer Diagnosis and Treatment in Special PopulationsView all 14 articles
Case Report: A Small Cell Lung Cancer Transformed from an EGFRmutated Adenocarcinoma Demonstrated a Long-term Remission to Anti PD-1 Antibody
Provisionally accepted
Yusuke Kawanaka
Kimio Yonesaka*Junko TanizakiOsamu Maenishi
Kazuko SakaiKazuhiro KakimiKazuto Nishio
Hidetoshi Hayashi- Kindai University Faculty of Medicine, Osaka-sayama, Japan
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Transformation to small cell lung cancer (SCLC) is a resistance mechanism in epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) after EGFR-tyrosine kinase inhibitor (EGFR-TKI) treatment. The efficacy of immune checkpoint inhibitor (ICI) in transformed SCLC remains to be elucidated. The present case report highlights a patient whose tumor underwent transformation to SCLC after developing resistance to an EGFR-TKI treatment. The patient subsequently achieved long-term remission lasting more than 5 years through treatment with an anti-PD-1 antibody nivolumab. Generally, the efficacy of ICI is inferior in EGFR-mutated NSCLC compared to those with EGFR wild-type NSCLC. However, some cases that have transformed to SCLC may be sensitive to ICI treatment. Further investigation is necessary to determine the efficacy of ICI in cases that have undergone transformation to SCLC.
Keywords: EGFR, EGFR-TKI, Non-small cell lung cancer, Small cell lung cancer transformation, case report
Received: 21 Jun 2025; Accepted: 28 Aug 2025.
Copyright: © 2025 Kawanaka, Yonesaka, Tanizaki, Maenishi, Sakai, Kakimi, Nishio and Hayashi. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Kimio Yonesaka, Kindai University Faculty of Medicine, Osaka-sayama, Japan
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