Respiratory Medicine Case Reports (Jan 2024)

Transformation of epidermal growth factor receptor mutated lung adenocarcinoma to small-cell carcinoma long after the cessation of tyrosine kinase inhibitor treatment: A case series and literature review

  • Kenya Miyamoto,
  • Hirokazu Ogino,
  • Takumi Kakimoto,
  • Yugo Matsumura,
  • Keiko Haji,
  • Atsushi Mitsuhashi,
  • Yutaka Morita,
  • Yuki Tsukazaki,
  • Yohei Yabuki,
  • Ryohiko Ozaki,
  • Hiroto Yoneda,
  • Seidai Sato,
  • Masaki Hanibuchi,
  • Yoshimi Bando,
  • Hiroshi Nokihara,
  • Yasuhiko Nishioka

Journal volume & issue
Vol. 51
p. 102076

Abstract

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Histological transformation to small-cell lung cancer (SCLC) is a well-known mechanism of acquired resistance to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), and almost all patients receive EGFR-TKIs at the time of transformation. We herein report three cases of EGFR-mutated lung adenocarcinoma that transformed into SCLC long after the cessation of EGFR-TKIs. Rapid tumor progression and elevated SCLC marker levels were observed at the time of transformation. Our case highlights the importance of considering SCLC transformation throughout the clinical course. Careful observation of the tumor behavior and SCLC markers should be performed to avoid diagnostic delays.

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