A Case of DILD Likely Induced by Molecular-Targeted Therapy Following Administration of an Immune Checkpoint Inhibitor Against Metastatic Lung Lesions from Tongue Cancer

In recent years, anticancer drug therapies have undergone remarkable developments. However, drug-induced interstitial lung disease (DILD) is an occasional serious adverse event of anticancer drug treatment involving immune checkpoint inhibitors and molecular-targeted therapies. We report a case of DILD caused by molecular-targeted therapy following administration of an immune checkpoint inhibitor in a patient with metastatic lung lesions from tongue cancer. A 54-year-old man with tongue cancer was diagnosed with metastasis to the lung and underwent radiotherapy with cetuximab (Cmab) in November 2015. In February 2016, the patient underwent combination therapy with Cmab and paclitaxel (PTX). An increase in pulmonary metastasis was detected in January 2018, and nivolumab (Nivo) was administered in February 2018. Seven cycles of Nivo were administered but tumor control was difficult. Therefore, Cmab and PTX combination therapy was administered again. After 11 cycles of Cmab and PTX, fever and cough appeared, and chest computed tomography revealed a shadowgram; blood examination showed an increase in inflammatory markers (WBCs 7340/μL, neutrophils 64.7%, eosinophils 1.9%, LDH 190 IU/L, CRP 15.47mg/dL, KL-6 191 U/mL, and SP-D <15ng/mL). DILD was diagnosed, and internal prednisolone was administered. After DILD improved, chemotherapy with carboplatin and PTX was initiated. The efficacy of chemotherapy was poor; the patient’s general state worsened, and he died 277 days after initiation of Cmab treatment.. Increased incidence of anti-EGFR-induced lung disease following immune checkpoint inhibitor therapy has been reported in patients being treated for lung cancer; thus, clinicians should be aware of the development of DILD in these patients.