A list of clinical and imaging findings that may help distinguish interstitial lung disease (ILD) associated with epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) therapy used in the treatment of lung cancer from lung-associated manifestations of COVID-19 infection was published in the Journal of Thoracic Oncology.
While EGFR-TKI–associated ILD is relatively rare, with a reported incidence in the range of 0.3% to 4.3% depending on patient population and specific EGFR-TKI used, it is considered to be the most serious adverse effect of EGFR-TKI treatment. Symptoms of this condition are often nonspecific and include dyspnea, fever, and cough, with diagnosis of ILD typically involving the exclusion of other diseases.
Symptoms of this condition are also observed in some patients infected with COVID-19, with fever, cough, fatigue, sputum production, shortness of breath, myalgias/arthralgias, headache, sore throat reported to be among clinical sequelae of the latter disease, thereby further complicating a diagnosis of ILD. In addition, some of the chest imaging findings associated with ILD, such as the presence of ground-glass opacities (GGOs), are also observed in some patients infected with the severe acute respiratory syndrome (SARS)-CoV-2 virus.
However, while early detection of ILD — as well as cessation of EGFR-TKI therapy and the timely administration of high-dose steroids — are key elements of the treatment of patients with ILD, the use of steroids may be harmful to patients infected with COVID-19. Hence, it is critically important to expediently distinguish these 2 conditions during the COVID-19 crisis.
The median time from initiation of EGFR-TKI therapy to development of ILD has been reported to range from approximately 4 to 8 weeks, and can be a useful factor in evaluating the likelihood of EGFR-TKI–associated ILD. Furthermore, results of rapid COVID-19 testing in patients with symptoms consistent with this infection can also facilitate treatment decision making in this setting, especially when performed within 2 months of EGFR-TKI initiation.
Regarding chest imaging, cardinal hallmarks of COVID-19 infection on chest computed tomography (CT) have been reported to include “bilateral distribution of [ground glass opacity] with or without consolidation in posterior and peripheral lungs,” whereas 4 patterns have been associated with ILD related to EGFR-TKI therapy: “nonspecific areas with ground glass opacity (GGO), multifocal areas of airspace consolidations, patchy distribution of GGO accompanied by interlobar septal thickening, and extensive bilateral GGO or airspace consolidations with traction bronchiectasis.”
Chang H-L, Chen Y-H, Yang C-J, et al. Epidermal growth factor receptor (EGFR) tyrosine kinase Inhibitor (TKI)-associated interstitial lung disease during the COVID-19 pandemic. J Thorac Oncol [published online May 5, 2020]. doi: 10.1016/j.jtho.2020.04.029