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Vol.58 No.7 contents | Japanese/English |
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- Case Report -
Multiple Primary Lung Cancers Containing Adenocarcinoma with EGFR Gene Mutation and Adenocarcinoma with Strong PD-L1 Positivity
Yasuyuki Hayashi1, Takahiro Kawai1, Teppei Tsuneishi1, Michinobu Hashimoto1, Shigeaki Iwatsubo1, Takashi Nishimura11Department of Respiratory Medicine, Kyoto Katsura Hospital, Japan
Background. Driver gene mutations, including epidermal growth factor receptor (EGFR) gene mutations, and immune escape mechanisms, including the programmed death-ligand 1 (PD-L1) pathway, have attracted attention as therapeutic targets for lung cancer. Case. A 57-year-old man was found to have a 35-mm mass in the right upper lobe, a 17-mm nodule in the right lower lobe, and swollen supraclavicular and mediastinal lymph nodes. A mediastinal lymph node biopsy led to the diagnosis of lung adenocarcinoma (cT4N3M0: Stage IIIC), which arose from the right upper lobe. The tumor was EGFR gene mutation (exon21 L858R)-positive and PD-L1-negative. After the initiation of afatinib treatment, the tumor in the right lower lobe and supraclavicular and mediastinal lymph nodes shrank; however, the tumor in the right upper lobe continued to grow. Another biopsy from the tumor in the right upper lobe revealed adenocarcinoma that was EGFR gene mutation-negative and PD-L1-positive (90%). Subsequently, the tumor in the right upper lobe was diagnosed as lung adenocarcinoma (cT2aN0M0: Stage IB), with strong PD-L1 positivity but no EGFR gene mutation. In contrast, the tumor in the right lower lobe was lung adenocarcinoma (cT1aN3M0: Stage IIIC), with an EGFR gene mutation (exon21 L858R) but no expression of PD-L1. This led to the diagnosis of multiple lung cancers. Conclusion. In cases in which multiple tumor sites show heterogeneous treatment responses, it is advisable to collect as many pathological specimens as possible in consideration of the possibility of multiple cancers or transformation.
key words: EGFR, PD-L1, Multiple primary lung cancers
Received: August 21, 2018
Accepted: October 2, 2018
JJLC 58 (7): 984-988, 2018
