Transient Asymptomatic Pulmonary Opacities during Osimertinib Treatment: "Stop or Go" Decision

Transient asymptomatic pulmonary opacities in a patient with MET exon 14 skipping non-small cell lung cancer: A case report

Mesenchymal epithelial transition factor receptor (MET) tyrosine kinase inhibitors (MET-TKIs) have been approved for the treatment of non-small cell lung cancers with MET exon 14 skipping mutations. Transient asymptomatic pulmonary opacities (TAPOs) associated with epidermal growth factor receptor (EGFR)-TKIs have been reported. Here, we report a case wherein ground-glass opacities (GGOs) appeared during the course of treatment with tepotinib, a MET-TKI, but spontaneously resolved with drug withdrawal, after which treatment was resumed with a reduced dose. Although there have been no reports of TAPOs with MET-TKIs, the clinical and imaging findings of this case were consistent with TAPOs. For TAPOs occurring because of MET-TKI, the drug can be continued under careful observation even if GGOs appear.

Molecular and Clinical Features of EGFR-TKI-Associated Lung Injury

The tyrosine kinase activity of epidermal growth factor receptors (EGFRs) plays critical roles in cell proliferation, regeneration, tumorigenesis, and anticancer resistance. Non-small-cell lung cancer patients who responded to EGFR-tyrosine kinase inhibitors (EGFR-TKIs) and obtained survival benefits had somatic EGFR mutations. EGFR-TKI-related adverse events (AEs) are usually tolerable and manageable, although serious AEs, including lung injury (specifically, interstitial lung disease (ILD), causing 58% of EGFR-TKI treatment-related deaths), occur infrequently. The etiopathogenesis of EGFR-TKI-induced ILD remains unknown. Risk factors, such as tobacco exposure, pre-existing lung fibrosis, chronic obstructive pulmonary disease, and poor performance status, indicate that lung inflammatory circumstances may worsen with EGFR-TKI treatment because of impaired epithelial healing of lung injuries. There is limited evidence from preclinical and clinical studies of the mechanisms underlying EGFR-TKI-induced ILD in the available literature. Herein, we evaluated the relationship between EGFR-TKIs and AEs, especially ILD. Recent reports on mechanisms inducing lung injury or resistance in cytokine-rich circumstances were reviewed. We discussed the relevance of cytotoxic agents or immunotherapeutic agents in combination with EGFR-TKIs as a potential mechanism of EGFR-TKI-related lung injury and reviewed recent developments in diagnostics and therapeutics that facilitate recovery from lung injury or overcoming resistance to anti-EGFR treatment.

Successful Re-administration of Osimertinib in Osimertinib-induced Interstitial Lung Disease with an Organizing Pneumonia Pattern: A Case Report and Literature Review

Osimertinib is the standard therapy for epidermal-growth-factor-receptor (EGFR)-mutant lung cancers. We herein report a case of osimertinib-induced interstitial lung disease (OsiILD) with an organizing pneumonia (OP) pattern and provide a literature-based review. Six months after osimertinib administration, a 75-year-old woman with right pleural carcinomatosis developed ILD with an OP pattern. After salvage chemotherapy, osimertinib with corticosteroid was successfully re-administered. A literature review suggested that 1) OsiILD with an OP pattern was rare but should be recognized, and 2) re-administration of osimertinib in OsiILD was successful in select patients. A criterion that determines whether a patient would benefit from re-administration is warranted.