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Vol.57 No.1 contents | Japanese/English |
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- Case Report -
A Case of Lung Adenocarcinoma That Transformed to Small Cell Carcinoma During Gefitinib Therapy
Chihiro Torigoe1, Takuya Ueno1, Suehiro Nishio1, Toshiyuki Sawabe1, Tokujiro Yano21Department of Respiratory Medicine, 2Department of Thoracic Surgery, National Hospital Organization Beppu Medical Center, Japan
Background. Lung adenocarcinoma can acquire resistance during therapy with epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI). This resistance is attributed to a second mutation of the EGFR gene in the majority of cases. However, the transformation to small cell carcinoma is another mechanism known to induce therapy resistance, although it is much less frequent. Case. A 73-year-old man was diagnosed with lung adenocarcinoma (cT4N2M1a, stage IV) with an EGFR mutation and treated with gefitinib as first-line therapy. The cancer exhibited a good response to the therapy. While the primary lesion stayed well-controlled, an elevated serum level of neuron-specific enolase (NSE) and liver tumors were newly detected. A liver biopsy to identify the origin of the tumors revealed small cell lung cancer (SCLC) with an EGFR mutation. Our findings suggested that the lung adenocarcinoma had transmutated to SCLC. The liver metastases decreased in size after the administration of chemotherapeutic agents for SCLC. Conclusion. When adenocarcinoma acquires resistance to EGFR-TKI therapy, the prediction and diagnosis of transformation to SCLC markedly helps optimize the therapeutic strategy. Therefore, if the lesion size and serum tumor markers indicate this specific transformation, a repeated biopsy should be strongly considered following the evaluation of risks and other conditions.
key words: Lung adenocarcinoma, Transformation to small cell lung cancer, EGFR-TKI
Received: September 29, 2016
Accepted: November 18, 2016
JJLC 57 (1): 35-40, 2017
